DeepResource | Observing the renewable energy transition ...
July 2014
A comparative review on ENERGY
Contents page
Some definitions and fundamental Laws- - - - 6
- Power - - - - - - - - 6
- Energy - - - - - - - - 6
- Law of Conservation of Energy - - - - 7
- Law of Conservation of Mass - - - - - 7
- Efficiency - - - - - - - - 7
- Production factor - - - - - - - 7
- Energy yield - - - - - - - 8
- Some efficiencies - - - - - - 8
- Units and conversion factors for power - - - 9
- Units and conversion factors for energy - - - 9
- Primary energy - - - - - - - 9
- Energy content of some fuels - - - - - 9
- Mechanical equivalent of heat - - - - - 10
- Energy conversion - - - - - - 10
- Carnot's formula - - - - - - - 10
- Newton's laws of motion - - - - - 11
Energy consumption of a household - - - - 12
Solar energy - - - - - - - 13
Wind energy - - - - - - - 19
Storage of solar and wind energy - - - - 21
Hydropower - - - - - - - 22
Geothermal energy - - - - - - 22
Tidal energy - - - - - - - - 23
Biomass - - - - - - - - 24
Energy storage in the batteries of electric cars - - 25
Energy Internet - - - - - - - 25
Combined Heat and Power - - - - - 26
Heat pump - - - - - - - - 26
Batteries - - - - - - - - 28
Atomic battery - - - - - - - 33
Walking and cycling - - - - - - 34
Electric bicycle - - - - - - - 36
Electric trains - - - - - - - 37
Vessels - - - - - - - - 39
Aircraft - - - - - - - - 40
The petrol car - - - - - - - 41
The electric car - - - - - - - 42
The hybrid car - - - - - - - 47
The fuel cell car - - - - - - - 49
The Hydrogen Economy - - - - - - 51
Nuclear fusion - - - - - - - 54
Nuclear energy - - - - - - - 56
Some facts, calculations, and things worth knowing
Energy consumption in the Netherlands - - - 62
The efficiency of the production of electricity - - - 62
The efficiency of the production of petrol - - - 62
The mass-energy equivalent - - - - - 63
The Sun - - - - - - - - 64
The Leopoldhove - - - - - - 67
Wind energy - - - - - - - - 69
Comparison of solar and wind energy - - - - 69
Some fuels and CO2 - - - - - - 70
The greenhouse effect - - - - - - 72
Light sources - - - - - - - 73
Aircraft - - - - - - - - 75
Electric train - - - - - - - - 77
Cycling - - - - - - - - 78
Electric bicycles - - - - - - - 81
The Hydrogen bicycle - - - - - - 85
Power plants - - - - - - - 86
The combined gas and steam plant - - - - 86
Electric cars - - - - - - - - 88
The plug-in hybrid car - - - - - - 91
Comparison of an electric car, a hybrid car and a petrol car 92
Electric race-car - - - - - - - 94
Comparison means of transport - - - - 95
Comparison power plants - - - - - 95
Some projects of Wubbo Ockels - - - - 97
- The sustainable sailboat - - - - - 97
- The Super bus - - - - - - - 97
- The World Solar Challenge - - - - - 98
- Hydrogen race - - - - - - - 98
Shell eco marathon - - - - - - 99
Bio fuel - - - - - - - - 100
A few more things worth knowing - - - - 102
Some units - - - - - - - - 107
Tables and graphs - - - - - - - 108
Alternative energy sources - - - - - 114
Tesla - - - - - - - - - 117
Storage of Energy - - - - - - - 118
Energy saving - - - - - - - 121
The collapse of the oil-economy - - - - 123
How will the future look? - - - - - - 125
The energy agreement - - - - - - 128
Energy content and water example - - - - 129
Energy consumption of some household appliances - 131
A book on Energy - - - - - - 133
Some preliminary remarks
|~ In this overview abbreviations will be avoided as much as possible |
|~ Units will not be written with a capital letter but always in full words |
|For example: newton-metre, volt, megawatt-hour etc. |
|~ Numbers are usually rounded. In this overview relations will be |
|emphasized and not the exact values in the first place. They do not |
|exist actually. Efficiencies of cars, lighting, energy generation etc. |
|are getting better all the time. Of course there are exact laws, such |
|as the Law of Conservation of Energy |
|~ Many numbers are a snapshot. Internet sites come and go |
|Therefore it is not always possible to verify all numbers via the internet. |
|~ The amount of energy needed to produce for example cars, windmills |
|solar panels, bio fuels etc. has not been taken in consideration. |
|~ There are as little units used as possible. Almost everything is |
|converted into kilowatt-hours and megawatt-hours. |
|~ Many people have no idea how the ratios are between the different |
|forms of energy generation and energy consumption. |
|This overview tries to tell facts which are the basis of clarification |
|~ Discussions about energy usually only concern electricity generation |
|So coal-fired power plants, nuclear power, hydropower, wind mills, |
|solar energy etc. One must however bear in mind, that the total |
|energy problem (in the Netherlands) is 3,4 times larger. It therefore |
|should also cover heating, industry, food production and transport. |
|~ This overview will be regularly updated on the basis of new facts, |
|new insights and comments from readers. |
Introduction
The energy consumption and the coherent environmental pollution is
proportional to the number of people on earth.
So the most effective environmental measure will be restricting the number
of people. That will be achieved (in the long run) when the reproduction rate
is not greater than 1. So not more than 2 children per couple.
After us the flood
In the book "Na ons de zondvloed" ("After us the flood") the author
P. Gerbrands, writes: "Within reasonable margins, growth of the number
of people and economic expansion will be possible, as long as we know
to limit ourselves to the consumption of the interest the earth us offers.
But if also the capital named earth itself is eaten, we as human species
will be entering a dead-end street"
Quote from “The Greens Party” program 2002
The uncontrolled growing population is a violent threat to life on earth. Yet
there is an explosive growth of the world's population. Just like China India
will soon be a country with more than one billion inhabitants. (in 2010, India
already had 1,2 billion inhabitants). There is a direct relationship between
pollution of the environment and the population rate. More people. produce
more waste, have more need for food, consume more raw materials, have
more hassle, have less living space, get less attention and need more money
The conclusion is clear: birth control is a necessity. If not, we all end up like
bacteria on a limited breeding ground. After unbridled growth unprecedented
mortality follows.
The population explosion
From 1990 to 2000 each year the world's population has increased with an
average of 1,5% Suppose that this increase had occurred always from the
beginning of our era until today. How large would the world's population be
now, based on 2 people in the year zero?
|~ after 2000 years the increase would be: 1,0152000 = 8,55 × 1012 |
|~ the surface of the earth is 4 π r2 = 4 π × 40 × 106 square kilometres |
|(r = the radius of earth = 6400 kilometres) |
|~ the total of earthlings would be: (2 × 8,55 × 1012 ) / (4 π × 40 × 106) |
|= 34000 per square kilometre, oceans and the poles included |
In reality there live on earth “only” 51 people per square kilometre. (in 2010,
on land) In the Netherlands the population density is 401 inhabitants per
square kilometre. That means a living place of 50 × 50 metres per person
Overview of the population growth (rounded)
| |1960 |2000 |2050 |
| the Netherlands |11 million |16 million |17 million |
| world population | 3 billion | 6 billion | 9 billion |
Daily increase of the world population (medium variant)
|year |world population |increase in 10 years |increase per day |
|2010 |6.909 million | | |
|2020 |7.675 million |766 million |210.000 |
|2030 |8.309 million |634 million |174.000 |
|2040 |8.801 million |492 million |135.000 |
|2050 |9.150 million |349 million | 96.000 |
The average increase of the world population in the period 2010 – 2050
amounts to 153.000 people per day. So 1 million per week
|In 2011 the 7 billionth earthling was born |
|In 2023 the 8 billionth is expected |
A comparative review on ENERGY
Some definitions and fundamental laws
Power
|Power is a measure of the speed at which energy can be |
|generated or used |
|power = energy / time |
Units
|1 watt = 1 joule / second |
For example
|~ An electric power plant has a capacity (power) of 600 megawatts, |
|even if the power plant is temporary out of operation |
|~ A car engine has a capacity (power) of 70 kilowatts, even if the car |
|is stationary. |
|~ An incandescent lamp has a capacity (power) of 75 watts, even if |
|the lamp is not in use or is still in the box. |
Power is a property.
Energy
|Energy is generated or used during a certain time |
|energy = power x time |
Units:
|1 joule = 1 watt x second |
For example:
|~ An electric power plant of 600 megawatts will generate in 5 hours: |
|600 megawatts × 5 hours = 3000 megawatt-hours electrical |
|energy (at full power) |
|~ A car engine of 70 kilowatts will generate in 2 hours |
|70 kilowatts × 2 hours = 140 kilowatt-hours mechanical energy |
|(at full power) |
|~ An incandescent lamp of 75 watts uses in 10 hours |
|75 watts × 10 hours = 750 watt-hours electrical energy |
Energy always generates something: electricity, movement,
light, heat, sound, radio waves, a chemical reaction etc.
In the shop one pays for the power
(for example what is stated on a vacuum cleaner)
At home one pays for the energy
(the energy used by the vacuum cleaner)
In daily life is valid:
|~ the basic unit for power is watt |
|~ the basic unit for energy is watt-hour |
Law of Conservation of Energy
|~ Energy cannot be lost |
|~ Energy cannot arise from nothing |
|~ Energy can be converted from one form to another, |
|but the sum of the energies cannot change |
Law of Conservation of Mass
|~ Mass cannot be lost |
|~ Mass cannot arise from nothing |
|~ Mass can be converted from one form to another, |
|but the sum of the masses cannot change |
Energy and mass are never “consumed”
In normal language mass and energy are “consumed” anyway.
For example, if you drive the tank of a car empty, then the petrol
is consumed. But in doing so the Law of Conservation of Energy
and the Law of Conservation of Mass will be applied
|During the combustion of petrol, chemical energy converts into mechanical |
|energy (= labour) and thermal energy (= heat). This is linked to |
|the chemical energy = the mechanical energy + the thermal energy |
|Petrol is a chemical compound of the elements carbon and hydrogen |
|The combustion of petrol with oxygen, results in carbon dioxide and water |
|the mass of petrol + oxygen = the mass of carbon dioxide + water |
Efficiency
|efficiency = useful energy / energy supplied |
For example:
|~ A car engine with a power of 50 kilowatts runs for 1 hour at full |
|power. Than the useful mechanical energy will be: |
|50 kilowatts × 1 hour = 50 kilowatt-hours |
|~ Suppose the amount of energy supplied is 200 kilowatt-hours |
|(that is approximately 22 litres of petrol) |
|~ The efficiency will be (50 / 200) × 100% = 25%. |
|So 150 kilowatt-hours of useless energy disappears in the form |
|of heat |
Efficiencies are always less than 100%.
So Perpetual Mobile does not exist.
Production factor (the availability)
|production factor = actual annual yield / theoretical annual yield |
For example
|~ Suppose a windmill has an actual annual yield of 10950 megawatt-hours |
|~ Its capacity (power) is 5 megawatts. Than the theoretical annual yield |
|will be 5 megawatts × 8760 hours = 43800 megawatt-hours |
|(1 year = 8760 hours) |
|~ The production factor will be (10950 / 43800) × 100% = 25% |
Efficiency and production factor are 2 completely different concepts
Some examples:
|~ The production factor of solar energy in the Netherlands is 11%, |
|in the Sahara 33%. The efficiency of a solar panel is 12% |
|~ The production factor of wind energy on land is 25%, at sea 40% |
|The efficiency of a wind mill is 50% |
|~ The production factor of an electric power plant is 80% |
|The efficiency of an electric power plant is 40% |
Energy yield
|energy yield = theoretical yield x production factor x efficiency |
Example:
|The energy yield of a solar panel in the Netherlands is |
|8760 kilowatt-hours × 11,4% × 12% = 120 kilowatt-hours |
|per square meter per year |
8760 kilowatt-hours = the theoretical yield per square meter per year
11,4% = the production factor of solar energy in the Netherlands
12% = the efficiency of a solar panel
Comparing energy sources
When comparing energy sources one should not only look at
the power, but also consider the energy yield.
This is especially true for solar and wind energy, because here
the production factor and the efficiency often will be very low
Some efficiencies (approximately)
- photosynthesis = 1%
- incandescent lamp = 5%
- electric solar panel = 12%
- concentrated solar power (CSP) = 15%
- LED lamp (light emitting diode) = 25%
- from food to mechanical energy = 25%
- petrol engine = 25%
- energy saving lamp = 29%
- nuclear power plant = 33%
- Atkinson petrol engine (Prius) = 34%
- diesel engine = 35%
- conventional electric power plant = 40%
- fluorescent tube = 41%
- steam turbine = 45%
- fuel cell = 50%
- wind mill = 50%
- combined gas and steam plant = 58%
- thermal solar panel (water heater) = 65%
- charging cycle of a lead-acid battery = 75%
- electrolysis of water = 80%
- hydroelectric power plant = 80%
- electric motor = 90%
- combined heat and power (CHP) = 90%
- generator in a power plant = 95%
- charging cycle of a super capacitor = 97%
Units and conversion factors for power
1 watt = 1 joule per second = 1 newton-metre per second
1 kilowatt = 1 kilo joule per second = 3600 kilojoules per hour
Units and conversion factors for energy
1 watt-second = 1 joule = 1 newton-metre
1 kilowatt-hour = 3600 kilojoules = 367.100 kilogram-metres
Primary energy
|Primary energy is the energy content of fuels in their natural |
|form, before any technical conversion has taken place |
Energy content of some fuels
1 kilogram of dry wood = 5,3 kilowatt-hours
1 kilogram of coal = 8,1 kilowatt-hours
1 cubic metre of natural gas = 8,8 kilowatt-hours
1 litre of petrol = 9,1 kilowatt-hours
1 litre of diesel oil = 10,0 kilowatt-hours
1 kilogram of hydrogen = 33,6 kilowatt-hours
In the following the energy consumption or energy yield is converted into litres
petrol-equivalent (if possible). That appeals a bit more to imagination and it
makes a good comparison possible
Thermal energy in 1 litre of petrol
|1 litre of petrol = 7800 kilocalories |
At an efficiency of 100% it is possible to increase the temperature of 7800 litres
of water with 1 degree Celsius (or to heat 78 litres with 100 degrees)
Mechanical energy in 1 litre of petrol
|1 litre of petrol = 9,1 kilowatt-hours |
This would keep a motor of 91 kilowatts running during 0,1 hours (= 6 minutes)
on full power. Because the efficiency of a petrol engine is approximately 25%,
such a motor runs only 1,5 minute on 1 litre of petrol, while 75% of the supplied
energy is converted into useless heat
|1 litre of petrol = 3.340.000 kilogram-metres |
With 1 litre of petrol one can theoretically lift up a Jumbo of 334.000 kilogram
10 metres. Bringing up such aircraft 10 kilometres, costs (apart from the
forward speed, air resistance, efficiency etc.) 1000 litres of fuel
Mechanical equivalent of heat
|This indicates the relationship between mechanical energy |
|(= labour) and thermal energy (= heat). |
|1 kilocalorie equals 427 kilogram-metres |
An example:
|~ To raise the temperature of 1 litre of water with 1 degree Celsius, |
|1 kilocalorie is needed (by definition). |
|~ If one put one's hand in 1 litre of cold water during 1 minute then |
|the temperature of the water has risen approximately with |
|1 degree Celsius. |
|~ This corresponds with a quantity of mechanical energy |
|of 427 kilogram-metres. |
|~ That will be sufficient energy to lift a cow (or 2 pianos) for 1 metre |
Heat is the most compact form of energy.
Energy conversion
|Conversion of heat into mechanical energy |
The efficiency will be limited according to Carnot's formula
The maximum achievable efficiency is about 50%
For example:
A steam turbine in a power plant has an efficiency of 45%
|Conversion of mechanical energy into electricity |
This can theoretically occur with an efficiency of 100%
For example:
A generator in a power plant has an efficiency of 95%
|Conversion of electricity into mechanical energy |
This can theoretically occur with an efficiency of 100%
For example:
The electric motor of the Solar car has an efficiency of 97%
Carnot's formula
|With Carnot's formula, one can calculate the maximum achievable efficiency, |
|at the conversion of thermal energy (= heat) into mechanical energy (= labour). |
The thermal energy is proportional to the absolute temperature T (kelvin)
|efficiency = (Thigh - Tlow) / Thigh |
Thigh - Tlow = the heat which is converted into useful mechanical energy
Thigh = the highest temperature in the process (the energy supplied)
Tlow = the lowest temperature in the process (the residual energy)
Example:
The inlet temperature of a steam turbine is 527 degrees Celsius and the exhaust
temperature is 207 degrees Celsius (0 degrees Celsius = 273 kelvin)
Thigh = 527 + 273 = 800 kelvin
Tlow = 207 + 273 = 480 kelvin
Than the maximum achievable efficiency is (800-480) / 800 = 0.4 = 40%
Newton's laws of motion
|1. Every object continues in its state of rest, or of uniform motion in a straight |
|line, unless compelled to change that state by external forces acted upon it |
|2. The acceleration a of a body is parallel and directly proportional to the |
|net force F acting on the body, is in the direction of the net force, and is |
|inversely proportional to the mass m of the body. F = ma |
|3. When two bodies interact by exerting force on each other, these action |
|and reaction forces are equal in magnitude, but opposite in direction |
(these laws are clearly visible when playing billiards)
1 newton
|1 newton is the net force required to accelerate a mass of |
|1 kilogram at a rate of 1 metre per second squared |
Energy consumption of a household
An average household in the Netherlands (statistically) consists of 2,28
people. In the year 2008 the energy consumption per household was:
|~ for lighting 528 kilowatt-hours of electricity was consumed |
|~ for the refrigerator, TV, washing, ironing, vacuuming etc. |
|3032 kilowatt-hours of electricity was consumed |
|~ for heating, hot water and cooking 1625 cubic metres |
|of natural gas was consumed |
|~ for the car 1444 litres of petrol was needed. |
The electricity is generated with an efficiency of 40%. The table below
shows how much primary energy per day is consumed by a household.
This is also converted into litres petrol-equivalent.
| |primary energy |litres petrol- |
| |(kilowatt-hours) |equivalent |
|lighting | 3,6 | 0,4 |
|refrigerator, TV, washing, ironing etc |20,8 | 2,3 |
|heating, hot water, cooking |39,2 | 4,3 |
|the car |36,0 | 4,0 |
|total |99,6 |11,0 |
Energy consumption of a household
[pic]
In 20 minutes a car consumes as much primary energy, as an average
Dutch household in 24 hours for lighting, refrigerator, TV, washing,
ironing, vacuuming etc.
(briefly to the letterbox by car)
It makes little sense to save on lighting as it is only 4% of the total energy
consumption. But it does help lowering the heating. All energy fed to lighting
and devices is fully converted into heat. A living room is not noticeably
warmer when the TV or the lights are switched on. Apparently the energy
consumption of the lighting and the TV is negligible compared to the energy
needed for heating. Many people think: “all tiny bits will help". The "tiny bits"
will contribute very little and give the misleading sense, that one does quite a
lot for the environment and that therefore one can further go one's own way.
(with the heating and the car)
If everyone does a little, we’ll achieve only a little
If comfort is at stake, one is no longer "at home".
Solar energy
Almost all the energy on earth comes from the Sun
|~ The intensity of solar radiation outside the atmosphere is |
|1,36 kilowatts per square metre. (that is the solar constant). |
|~ At the height of the earth's surface and at a completely |
|unclouded sky, the solar radiation has an intensity of 1 kilowatt |
|per square metre. (at perpendicular radiation) |
|~ So the theoretical annual yield per square metre is |
|8760 kilowatt-hours (1 year = 8760 hours) |
|~ The actual annual yield of solar energy in the Netherlands |
|is 1000 kilowatt-hours. measured at a horizontal plane of |
|1 square metre, seasons, cloudy sky, day and night included |
|~ So the production factor adds up to |
|(1000 / 8760) × 100% = 11,4% |
|~ To maximise the yield of sunlight in the Netherlands, a fixed |
|solar panel should be mounted under an angle of 36 degrees |
|and aimed at the south |
|~ A solar panel mounted at an angle of 36 degrees has a surplus |
|of 15% compared to a horizontally mounted solar panel. |
|~ A solar panel that rotates with the position of the sun, (a sun |
|tracking system), still delivers 30% extra energy. |
|~ At perpendicular radiation of sunlight on a solar water heater, |
|a solar panel, a parabolic mirror or a solar trough, the amount |
|of irradiated energy per square metre and during the same time |
|is (of course) always the same |
|~ At a heliostat the radiation is never perpendicular. There, the |
|angle of radiation is determined by the distance from the |
|heliostat to the solar tower and the position of the sun |
|~ In the Netherlands the amount of irradiated solar energy on a |
|horizontal plane, in summer (June, July, August) is 6 times |
|as much as in winter (December, January, February) |
|Of course that will not be the same every year. see Leopoldhove |
|~ In the Netherlands the energy captured by a solar panel consists |
|of 40% direct sunlight and 60% indirect sunlight. |
|~ In the Sahara the amount of irradiated solar energy on a |
|horizontal plane is only 3 times as much as in the Netherlands |
|(during a year and on the same surface) |
|~ The annual amount of solar energy irradiated on the whole earth |
|is 8000 times as much as the annual world energy consumption |
Solar energy in the Netherlands
|~ in 2009 the yield of solar energy was 0,05 billion kilowatt-hours. |
|~ then the electricity consumption was 113,5 billion kilowatt-hours |
|~ so the share of solar energy was 0,04% |
Solar energy in Germany
|~ in 2009 the yield of solar energy was 6,58 billion kilowatt-hours. |
|~ then the electricity consumption was 592,5 billion kilowatt-hours. |
|~ so the share of solar energy was 1,11% |
In 2012 the amount of solar energy in Germany exploded to more
than 28 billion kilowatt-hours. That is more than the world production
of solar energy in 2009
Some possibilities to use solar energy are:
|~ photosynthesis (bio fuel) |
|~ direct generation of electrical energy |
|(electric solar panel) |
|~ production of electricity with concentrated solar |
|irradiation (concentrated solar power) |
|~ water heating (solar water heater) |
Efficiencies and revenues of solar energy at an irradiation of
1000 kilowatt-hours per square metre per year (in the Netherlands)
| |efficiency |kilowatt-hours |energy type |
|bio fuel |< 1% | 3 |chemical |
|electric solar panel |12% |120 |electric |
|solar water heater |65% |650 |heat |
The average electricity consumption of a household in the Netherlands is 3600
kilowatt-hours per year. So it takes 30 square metres of solar panels to fulfil
this need. It seems the efficiency of an electric solar panel can still be increased
to 24% Then 15 square metres would be sufficient.
Are there any higher returns possible on solar energy?
|~ concentrated solar power with solar cells provide a return of |
|more than 35% |
|~ with nano-antennas an efficiency of 80% would be achievable. |
|~ very high returns seem possible with light trapping |
Concentrated solar power (CSP)
At concentrated solar power the solar radiation is concentrated on a small
surface by means of mirrors. This can be done in different ways:
|~ with parabolic mirrors |
|~ with solar troughs |
|~ with heliostats |
Condition for "concentrated solar power" is a sun-tracking system. The accuracy
with which the position of the sun must be followed, is at least 1 degree. That
means, that the system should be adjusted every 4 minutes. In addition, the sun
must shine freely. At a cloudy sky "concentrated solar power" doesn’t work.
Therefore it is not applied in the Netherlands. The gains of the higher yield, are
nullified by the fact that the sun only shines a few hours a day at full strength in
the Netherlands (on average)
Parabolic mirrors
[pic]
|~ A parabolic mirror revolves around 2 perpendicular |
|axes and follows the position of the sun. |
|~ The sunlight can be focused by a factor of 500. |
|~ Then there is a temperature of 1000 degrees Celsius |
|in the focal point. |
|~ A hot-air engine (Stirling engine) might be posted |
|there, propelling a generator |
|~ The generator generates electricity. |
Solar troughs
[pic]
|~ A solar trough is a trough-shaped mirror, with a parabola |
|shaped cross-section. |
|~ The longitudinal-axis is in North-South direction and the solar |
|trough revolves around this axis in the same position as the sun, |
|so every day from east to west. |
|~ The concentration of sunlight in the "fire line" is a factor 80. |
|A temperature of 400 degrees Celsius is reached there. |
|~ Oil is heated in a tube in the fire line. |
|~ In a heat exchanger water is heated to hot steam. |
|Then electricity is generated in the usual manner. |
|~ The efficiency of converting the solar radiation into hot steam |
|is 50%. From hot steam to electricity is 30%. So the total |
|efficiency is 15% (so little higher than at electric solar panels). |
|~ The advantage of solar troughs is, that part of the absorbed |
|solar heat can be temporarily stored. |
|Thus brief sunless periods can be bridged |
Heliostats
[pic] [pic]
|~ A heliostat is a slightly curved or flat mirror, with 2 axes |
|keeping up the position of the sun. |
|~ The sunlight reflected by the heliostat is focussed on the top |
|of a "solar tower". The top of this solar tower, which is about |
|100 metres high, is lightened by a field of hundreds of heliostats |
|and is therefore the common focal point of a huge surface with |
|a few hundred mirrors. |
|~ All mirrors must be focussed continuously and individually. |
|Very high temperatures are reached. in the top of the tower, |
|up to 1000 degrees Celsius. |
|~ The captured heat is used for the generation of electricity |
|~ The temperature generated at parabolic mirrors or heliostats |
|is much higher than at solar troughs. Therefore the efficiency |
|of electricity generation is also higher (Carnot) |
Concentrated solar power with solar cells
"Concentrated solar power" (in a milder form) can also be applied in combination
with appropriate solar cells. Spectrolab delivers solar cells, that can tolerate a
power of 50 watts per square centimetre, provided they are cooled with a
temperature below 100 degrees Celsius. Under these conditions an efficiency of
over 35% will be achieved
Greenpeace solar panel
In the year 2000 Greenpeace introduced an electric solar panel in
the Netherlands:
|~ the effective surface is 0,75 square metres |
|~ the yield is 80 kilowatt-hours per year |
|~ that is an average of 220 watt-hours per day. |
|~ that will be sufficient to watch TV for 2 hours per day |
|~ this solar panel saves 80 × € 0,20 = € 16,- on an annual basis |
|~ the panel costs € 454,- (subsidies included) |
|~ the payback-period is 28 years |
An advertisement for solar panels
A quote from a recent advertisement for solar panels:
"This solar panel which has been manufactured with Laser Technology (?)
has a high efficiency at cloudy skies and until late in the evening" Yes,
perhaps the efficiency is high, but the yield will be almost zero at cloudy
skies and in the evening, because the amount of irradiated energy then will
be very little.
Solar energy has the potential, to ever be interesting:
|~ in the Netherlands the amount of radiant solar energy |
|on a surface of 25 square kilometres, annually amounts: |
|25.000.000 square meters × 1000 kilowatt-hours per |
|square meter = 25 billion kilowatt-hours. |
|~ this is the amount of energy which equals 1 kilogram-mass |
|~ at an efficiency of 100% it would be sufficient for almost |
|a quarter of the annual electricity consumption in the |
|Netherlands. |
|~ there is no practical possibility yet to capture this energy |
|in an efficient way |
The Waldpolenz Solar Park
[pic]
The Waldpolenz Solar Park is a large sun-voltaic power plant
in Germany and is located near Leipzig.
|~ the electricity is generated by 550.000 electric solar panels |
|~ the total panel surface is 400.000 square metres |
|~ the total land area is 1 square kilometre |
|~ the capacity (power) of this power plant is 40 megawatts |
|~ the annual production is 40.000 megawatt-hours |
|~ the production factor is 11,4% |
|~ a 600 megawatt power plant produces 100 times |
|as much energy in 1 year. |
Compare the largest windmill in the world.
That generates 21.000 megawatt-hours per year
A sun-thermal power plant with heliostats
In early 2009 near Sevilla in Spain a large commercial sun-thermal
power plant, the PS20, was put into service.
|~ the sunlight is captured by 1255 heliostats |
|~ each heliostat has an area of 120 square metres |
|~ so the total surface of the heliostats will be |
|150.600 square metres |
|~ the heliostats rotate with the position of the Sun |
|~ the capacity (power) of this power plant is 20 megawatts |
|~ the annual production is 48.000 megawatt-hours |
|~ the production factor is 27,4% |
|~ a 600 megawatt power plant produces almost 90 times |
|as much energy in 1 year |
The concentrated sunlight heats a barrel with water, which is located on top
of a tower of 160 metres. Electricity is generated in the usual way using the
hot steam that arises.
This sun-thermal power plant has the advantage of the possibility of constant
energy delivery (during daytime), thanks to a buffer of hot steam with a heat
capacity of 15 megawatt-hours. The production factor has therefore been
significantly increased.
A sun-thermal power plant with solar troughs
An even larger sun-thermal power plant has been built in Andalusia,
the Andasol Solar Power Station.
|~ the solar radiation is collected in solar troughs |
|~ the solar troughs are drawn up in north-south direction and |
|rotate along with the position of the sun |
|~ the mirrors are drawn up in rows, which are 150 metres long |
|~ the reflecting surface of a single row is 800 square metres |
|~ the total surface of the troughs is 1,53 square kilometres |
|~ the total land area of the plant is 6 square kilometres |
|~ there is a steel tube in the fire line, where oil flows |
|~ the concentrated solar radiation heats the oil to 400 degrees |
|celsius |
|~ in a heat exchanger water is heated to steam |
|~ electricity is generated in the usual manner by means of the |
|steam. |
|~ the capacity (power) of this power plant is 150 megawatts. |
|~ the annual production is 495.000 megawatt-hours |
|~ the production factor is 37,6% |
|~ a 600 megawatt power plant produces 8,5 times |
|as much energy in 1 year |
During daytime a part of the collected heat is stored in a huge tank with
25000 tonnes of molten salt. The heat capacity is sufficient to generate
electricity for 7 hours, when the sun doesn't shine.
At Andasol the amount of irradiated solar energy is 2100 kilowatt-hours
per square metre per year, so 2 times the irradiation in the Netherlands
Comparison of the above mentioned solar power plants
| |power |annual production |production |
| |(megawatts) |(megawatt-hours) |factor |
| Waldpolenz Solar Park | 40 | 40.000 |11,4% |
| Sevilla (heliostats) | 20 | 48.000 |27,4% |
| Andasol (solar troughs) |150 |495.000 |37,6% |
Wind energy
Near Zoetermeer, there is a wind mill with a capacity of 1,5 megawatts
(= 1500 kilowatts). That equals the power of 20 cars. (the Opel "Astra",
has an engine of 74 kilowatts). A few years ago this was the largest wind
mill in the Netherlands.
|~ the hub height of this mill is 85 metres and the diameter of |
|the blades is 70 metres |
|~ so the highest point reached by the blades is 120 metres |
|~ the capacity (power) is 1,5 megawatts |
|~ so the theoretical annual yield is 1,5 × 8760 hours = |
|13140 megawatt-hours (1 year = 8760 hours) |
|~ the actual annual yield is 3000 megawatt-hours |
|~ so the production factor is (3000 / 131400) × 100% = 23% |
The generated energy by a wind mill is proportional to the 3rd power
of the wind speed. If the wind blows "half" force, the energy yield is
only 1/8 compared with "full" force.
|~ the production factor of a windmill on land is 25% |
|~ the production factor of a windmill at open sea it is 40% |
The production factor increases, as the windmill is higher and larger
Wind energy in the Netherlands
|~ n 2009 the yield of wind energy was 4,6 billion kilowatt-hours |
|~ then the electricity consumption was 113,5 billion kilowatt-hours |
|~ so the share of wind energy was 4,1% |
Some Dutch wind farms
| |number of |power per |total |annual yield |
| |windmills |windmill |power |(megawatt-hours) |
| Egmond aan Zee |36 |3 megawatts |108 megawatts |378.000 |
|10 km off the coast | | | | |
| IJmuiden |60 |2 megawatts |120 megawatts |435.000 |
|23 km off the coast | | | | |
| Westereems |52 |3 megawatts |156 megawatts |470.000 |
|Eemshaven, on land | | | | |
A 600 megawatt power plant generates 4.200.000 megawatt-hours per year.
That is about 10 times as much as 1 wind farm
The largest wind mill in the world
The largest wind mill in the world is the Enercon E-126
|~ the hub height is 135 metres |
|~ the diameter of the blades is 126 metres |
|~ so the highest point that is reached by the blades is |
|198 metres |
|~ the maximum power is 7,5 megawatts (100 cars) |
|~ at a production factor of 32% (on land) the annual |
|yield is 21.000 megawatt-hours |
|~ a 600 megawatt power plant produces 200 times |
|as much energy in 1 year |
At Estinnes (Belgium) 11 of these mills are in operation
Storage of solar and wind energy
Large-scale application of solar and wind energy is only possible, if a solution will
be found for storing very large amounts of electrical energy. The problem occurs
especially with solar energy, that the need for energy usually is greatest, when the
Sun has gone down behind the horizon already. Solar and wind energy is usually
returned to the grid. Than (temporarily) less "grey" energy needs to be generated.
Some possibilities for large-scale storage of electrical energy
|~ pumping of water to an higher reservoir at a |
|hydroelectric power plant |
|~ pumping up water from an energy island |
|~ compressing air in underground salt domes |
|~ the production of hydrogen |
|~ energy storage in batteries of electric cars |
|~ energy storage in vanadium redox batteries |
Hydro power
Hydro power is of limited significance even in Switzerland, because the energy
consumption increased in recent years. Nowadays in Switzerland 40,5% of
electrical energy is generated by nuclear power plants. Only in Norway virtually
all electrical energy is generated by hydro power
Worldwide 16,5% of all electrical energy is generated by hydro power.
That is slightly more than by nuclear energy
The largest hydroelectric power plants in the world
A very large hydroelectric power plant, the Itaipu Dam is located at the
border between Brazil and Paraguay. Its reservoir is 170 kilometres long.
|~ the capacity of this power plant is 12.600 megawatts |
|~ the energy yield is 75 billion kilowatt-hours per year |
In China an even greater hydroelectric power plant has been built, the
Three Gorges Dam
|~ the energy yield is 84 billion kilowatt-hours per year |
|~ that is 3% of the electricity consumption in China |
For comparison:
Annually the Three Gorges Dam will produce 20 times as much energy as
a 600 megawatt power plant.
Teletext 19 May 2011
China admits, that there are problems at the three Gorges Dam in the Yangtze
River. Agricultural land drying out, the River is less navigable and many people
have lost their work. For the construction of the dam half a million people had
to leave their homes
Geothermal energy
Geothermal energy is extracted from the heat in the earth. The temperature of
the surface of the earth increases with depth; roughly with 30 degrees Celsius
per 1000 metres. That is an average value. This can vary (strongly) depending
on local circumstances. In volcanic areas temperatures are considerably higher.
At a depth of 5000 metres the average temperatures are 150 degrees Celsius.
Geothermal energy may play a (modest) role in future energy supply. It is now
possible to exploit geothermal energy on a commercial scale thanks to the
improved drilling techniques developed for the extraction of oil at great depth
Geothermal energy is:
|~ clean, durable and inexhaustible |
|~ not depending on weather conditions |
|seasons and time of the day |
|~ the production factor is 100% |
|~ there is no CO2 emission |
|~ the energy is constantly available, so |
|there is no storage problem |
Geothermal energy in a few countries
| |power |annual energy yield |
| |(megawatts) |(megawatt-hours) |
| China |1440 |12.600.000 |
| Sweden |1140 |10.000.000 |
| USA | 990 | 8.680.000 |
| Iceland | 760 | 6.610.000 |
| New Zealand | 220 | 1.970.000 |
| Japan | 160 | 1.430.000 |
For comparison:
A 600 megawatt power plant generates 4.200.000 megawatt-hours per year
Geothermal energy is already used on small scale in the Netherlands. In the West
of the country some greenhouses are heated with geothermal energy while there
are also advanced plans for the use in new residential areas in the Hague.
Press release on 23 September 2010
Recently completed test drilling has shown that there is enough water with a high
temperature available 2000 metres below ground level to heat the targeted 4.000
homes and 20.000 square metres of business premises in the Hague Southwest,
as it turns out from the test results. "We had a final goal of 75 °C. Our goal has
been achieved”
Tidal energy
The energy generated by a tidal power plant is indirectly derived from the moon.
The largest tidal power plant in the world is in France at La Rance. (since 1966)
|~ the difference in height between ebb and flood tide is |
|very large, up to 13 metres. |
|~ the capacity of the tidal power plant is 320 megawatts |
|~ the production factor is approximately 20% |
|~ the annual energy generated is 540.000 megawatt-hours |
|~ a 600 megawatt power plant produces 8 times |
|as much energy in 1 year |
During the "turning point", that is the period in which flood turns into ebb or
conversely, there is virtually no energy excited. In an ordinary hydroelectric
power plant with a reservoir, the production factor can rise to 100%.
Biomass
Biomass is the collective name for organic materials, which can be used for the
generation of "sustainable energy". Examples of such organic materials are: fruit
vegetable and garden waste, wood and manure. Special "energy crops" can be
grown, such as oilseed rape, maize and sugar cane, which may be used as fuel
for vehicles possibly after digestion, fermentation or gasification,
An example of this is bio fuel
During the growth of trees for example, oxygen is produced and carbon dioxide
(CO2) is absorbed from the atmosphere. When combustion takes place the
opposite occurs. Net, this so-called "short cycle" does not pollute the environment
("CO2 neutral"). The advantage of using biomass: there is no storage problem.
The biomass can be incorporated in the fuel of coal-fired power plants. (those
coal-fired power plants which are so maligned by environmentalists). The extra
CO2 released is "green" and is deducted from the emissions according to "Kyoto".
Biomass in the Netherlands
|~ in 2009 the energy generated by the burning of biomass in |
|the Netherlands was 7,8 billion kilowatt-hours. |
|~ the electricity consumption then was 113,5 billion kilowatt-hours. |
|~ so the share of biomass was 6.9% |
This can not be much more in the near future, because the amount of biomass
is limited. One can therefore have legitimate doubts about energy suppliers who
are going to sell huge quantities of "green" energy to the consumer suddenly.
Energy storage in the batteries of electric cars
Maybe someday wind energy will play an important role in common electricity
generation. Naturally the supply of wind energy is subject to severe and often
rapid fluctuations. The production factor is at best (at sea) 40% because the
wind is not always blowing (hard). So in 60% of time no or very little wind
energy is excited. Therefore the existing infrastructure for electricity generation
should be maintained for 100%.
At large-scale production of wind energy, storage of electricity is necessary to
compensate for the fluctuations in the supply. Energy storage can be achieved
by production of hydrogen via electrolysis of water, a cumbersome method with
little (total) efficiency. The use of batteries seems to be a more realistic solution
to the storage problem of electrical energy, When electric cars will be widely
used, the potential storage capacity for electrical energy will be very large.
If we assume, that there are 1 million electric cars (in the Netherlands there are
over 7 million cars) and each battery has a capacity of 25 kilowatt-hours, then
25 million kilowatt-hours of total storage capacity will be available.
For comparison:
A 600 megawatts power plant delivers in 24 hours at full power:
600 × 24 = 14.400 megawatt-hours = 14,4 million kilowatt-hours
This form of energy storage requires an intelligent, automated energy
management system. (Energy Internet)
Energy internet
Energy internet (smart grid) is an energy management system, which controls
the distribution between the energy generated by renewable energy sources
(wind and solar energy) and conventional power plants.
The aim is:
|~ the maximum flattening of the peaks and off-peaks |
|in the generation of energy. ("peak shaving") |
|~ compensation for the varying energy yield of |
|renewable energy sources |
A primitive form of energy management already exists in the system of "off-peak
hours", which is often applied by suppliers of electricity. Electric boilers are
remotely enabled when the demand for electricity is low. (usually at night and in
weekends)
An intelligent energy management system may offer the following options:
|~ thermostats of devices (for example, boilers and air conditioning) can |
|be remotely and automatically disabled or enabled according to the |
|instantaneous load of the grid. |
|~ batteries of electric cars can be loaded for one moment and the loading |
|can be stopped or the energy from the batteries can be (partially) fed |
|back to the grid, when an energy deficit is likely to occur. |
|~ as the wind varies, the energy of wind farms will be proportionally |
|supplemented by energy from (rapid starting) gas-fired power plants. |
Combined Heat and Power
The efficiency of electricity production in a power plant is approximately 40%.
Therefore 60% of primary energy is lost through the cooling water. Many plants
are using this "waste heat" nowadays for district heating and the heating of
greenhouses. Often the heat must be transported and distributed over great
distances, which obviously yields quite a few losses. The overall efficiency of
the power plant has nevertheless been increased significantly.
At Combined Heat and Power the generation of heat and electricity (power) is
linked directly. Heat and electricity are then exited at the consumer. The main
issue is the heat production while electricity is a by-product. The total efficiency
is very high, because there is virtually no heat lost and all electricity is being used.
(excess electricity is fed into the grid). Combined Heat and Power is widely
applied in hospitals, swimming pools, factories and horticulture. In horticulture
the CO2 released is very welcome, because it stimulates the growth of the plants.
(carbon dioxide assimilation).
The total efficiency of Combined Heat and Power is about 90%.
Heat pump
A heat pump transfers heat from a low temperature level to a higher level. For
example, the lower level is the ground heat which is approximately 12 degrees
during the whole year at any depth. The heat pump works according to the same
principle as a refrigerator, but the goal is different. In a refrigerator the interior is
chilled and the temperature outside is of no importance. In a heat pump, the heat
is important. A room can be heated with it. The heat that arises is the total of the
pump-energy and the heat from the ground. The efficiency seems to be more
than 100%. With a heat pump one uses the concept of COP (= coefficient of
performance). For example, the COP = 4. Then 3 times as much (free) heat,
from the ground is tapped compared with the pump energy. The total amount of
heat produced is then 4 times the pump-energy. The COP of a heat pump is
greater when the temperature difference between inlet and exhaust is smaller.
Therefore, a heat pump is often used in combination with floor heating.
Press release on 13 January 2009:
"In the Hague a seawater heat plant has been opened. Over 800 homes in the
Scheveningse district "Dune village" will be equipped with heat, which will be
extracted from the North Sea ".
Some data:
|~ the system consists of 1 large central heat pump, |
|that will pump up the temperature of seawater |
|from 5 degrees to 11 degrees Celsius. |
|~ through a distribution network, water of this |
|temperature will be supplied to the houses. |
|~ each house has a small heat pump, which will |
|increase the temperature to 45 degrees for |
|(floor) heating and 65 degrees for hot water |
Ice stadium and swimming pool heating and cooling each other
The largest indoor sports centre of the Netherlands has been opened in
Dordrecht. Heat released when making ice for the ice rink, will be used
for heating water of the swimming pool, the buildings and the restaurant.
In total 50% less energy is used than in comparable complexes
Combined Heat and Power (CHP) compared with a heat pump
|~ CHP is at the expense of the efficiency at electricity generation. |
|For a useful amount of heat, the cooling water should not be too |
|cold, so the efficiency of electricity generation goes down. (Carnot) |
|~ CHP is not "green", because it will only work on electricity |
|generated by means of fossil fuels. |
|~ Heat pumps can work on "green energy" (in the distant future). |
|~ A heat pump is roughly 4 times more efficient than "ordinary" |
|electric heating. |
|~ Some heat pumps can work in 2 directions. They therefore can be |
|used for heating or cooling. Also, they can simply be turned off, |
|this is in contrast to CHP. |
Possibilities for the generation of heat (idealized)
|primary energy = 100% |electricity |waste heat |useful heat |
|burning |- |- |100% |
|generating of electricity |40% |60% |- |
|combined heat and power |40% |- | 60% |
|heat pump |(40%) |60% |160% |
Electricity (40%) is completely converted into heat in the heat pump.
At a coefficient of performance = 4, useful heat generated becomes
4 × 40% = 160%. So the heat pump is significantly more efficient than
combined heat and power.
If the waste heat is also used, the generated heat will be even 220%
Batteries
Alkaline battery (AA-cell):
|~ contains 1,5 ampere-hour at 1,5 volt, that is 2,25 watt-hours |
|~ such a battery costs approximately € 0,40 |
|~ so 1 kilowatt-hour from an alkaline battery costs € 178,00 |
Rechargeable nickel-metal hydride battery (AA-cell)
|~ contains 2,7 ampere-hour at 1,2 volt, that is 3,24 watt-hours |
|~ the use of rechargeable batteries is much cheaper and more |
|environmentally friendly than ordinary batteries. |
The rechargeable nickel-metal hydride batteries of GP PowerBank meet up to
the electrical specifications for 100%, which may be called noteworthy. I haven't
tested other brands, but there is a lot of “chaff among the wheat", especially in
quickly rechargeable batteries. Unfortunately, the dimensions of AA-cells have
not been normalized apparently, or the manufacturers are not always keeping up
to the standard. This may cause (mechanical) problems at some applications
when alkaline batteries are replaced by rechargeable nickel-metal hydride
batteries. Sometimes they are a bit longer and thicker than the alkaline batteries.
Also the lower clamp voltage (1,2 volt) may be a disadvantage.
Some of the features of rechargeable batteries
| |watt-hours |cell voltage |efficiency |self discharge |
| |per kilogram |volt |charging cycle |per month |
|lead-acid battery | 30 - 40 |2,1 |50 - 92% |3 – 20% |
|nickel-cadmium battery | 40 - 60 |1,2 |70 - 90% | 10% |
|nickel-metal hydride battery | 30 - 80 |1,2 | 66% | 30% |
|lithium-ion battery | 160 |3,6 |80 - 90% |5 – 10% |
|lithium-ion polymer battery |130 – 200 |3,7 | 99% | 5% |
|zinc-air battery | 470 |1,6 |- - - |- - - |
|vanadium redox battery | 10 - 20 |1,2 |75 - 80% |- - - |
The zinc-air battery
The zinc-air battery ("electric fuel") is not rechargeable, in the usual meaning of the
word. When the battery is empty, the (zinc) anodes must be replaced. Application
in an electric car, might be an advantage, because then one doesn't have to wait
for hours until the battery is recharged. Instead, the battery has to be exchanged
with a regenerated one. The zinc-air battery for use in electric cars is still in the
experimental stage. The energy density is 12 times as much as a lead-acid battery,
but still 27 times less then petrol. (at the same weight).
The vanadium redox battery
The vanadium redox battery is a liquid battery with a very large energy-content.
The electrolyte is a solution of vanadium sulphate in sulphuric acid. The battery
contains a membrane, which distributes the electrolyte into 2 halves. This
membrane will only allow positive ions to go through.
[pic]
During loading a redox reaction takes place in the battery. The ionisation degree
of the atoms changes. In one half the electrolyte is reduced and in the other half
oxidized. This will create opposite charges. At discharging, the reverse reactions
will take place Both halves are connected with their own storage tank with
electrolyte. The amount of electrolyte (and thus the energy content of the battery)
can be made very large. The electrolyte from the storage tank is pumped along the
corresponding electrode. When the battery delivers energy, positive ions flow
trough the membrane, and electrons trough the external circuit. While discharging
the battery, the charges on both sides of the membrane are settled. When the
electrolytes are developed, they should be replaced by fresh electrolytes with a
new load. The battery can also be recharged by an electric current.
Some of the features:
|~ the battery is especially suited for stationary applications and can be |
|used to level off the fluctuating yield of solar panels and windmills |
|~ the energy density is low, approximately 20 watt-hours per kilogram |
|~ the lifespan is very large, more than 10,000 load cycles |
|~ the power is determined by the dimensions of the membrane |
|~ the energy content is virtually unlimited and is determined by the size |
|of the storage tanks with the electrolytes |
|~ already a vanadium redox battery has been made with an energy |
|content of 12 megawatt-hours. |
|~ an electric train could run 2000 kilometres on this energy content |
|(a 4-wagons Double Decker consumes 6 kilowatt-hours per kilometre) |
|~ loading may be done (very quickly) by replacing the electrolytes, |
|but the battery can also be recharged by an electric current |
|~ perhaps the redox battery is interesting for application in an electric car, |
|because loading can be done very quickly by replacing the electrolytes |
The principle of the vanadium redox battery resembles "Blue Energy" There
also a membrane is applied that separates 2 "electrolytes", salt and fresh water
which have different charges
The lifetime of a rechargeable battery or accumulator
The lifetime of a rechargeable battery or accumulator will strongly be influenced
by the depth of discharge. The end of lifetime is reached, when the capacity is
only 70% of the replacement value. The lifetime is expressed in the number of
discharge cycles consumed.
For lithium-ion batteries is valid:
|depth of |lifetime |
|discharge |discharge cycles |
|100% | 500 |
| 50% |1500 |
| 25% |2500 |
| 10% |4700 |
The effective number of ampere-hours of a battery
The effective number of ampere-hours of a battery, will be heavily
dependent on the current supplied.
For example:
|~ a battery of 100 ampere-hours can deliver a current |
|of 5 amperes during 20 hours |
|~ at a current of 25 amperes, the battery will be empty |
|in 2 hours, which corresponds to 50 ampere-hours |
The working cycle of a battery of an electric car
The working cycle consists of 4 sub processes:
|~ converting the mains voltage to the desired voltage |
|of the battery charger |
|~ charging the battery |
|~ discharging the battery |
|~ converting the battery direct current to alternating |
|current with the desired frequency for driving the |
|electric 3-phase induction motor of an electric car |
Quote from "De Ingenieur" ("The Engineer") 13 November 2009:
"Researchers from the Technion-Israel Institute of Technology have invented
a battery which is powered by oxidation of silicon. A battery of this type will
have an energy density which is nearly sixty times larger than a high-quality
lithium battery. Theoretically the energy density is 8,5 kilowatt-hours per
kilogram (which is almost as much as petrol) or 21,1 kilowatt-hours per litre.
An industrial introduction may take place within 3 years. Large silicon
rechargeable batteries for use in cars might be available in about 10 years”
This story is too good to be true and therefore it is probably not true. Would
it be true, then the problem of electric cars would have been resolved.
With a battery-weight, equal to a full petrol tank, (and with half the volume),
the action radius of an electric car would then be about 2000 kilometres. If
the batteries are always charged, when the car doesn't drive, the average
energy-stock would be more than enough for everyday use. The question
remains: “how to heat the car in winter”. If the energy is derived from the
battery then it will be at the expense of the action radius
Toshiba announces a breakthrough in rechargeable lithium-ion batteries
Early 2008 Toshiba launched an improved lithium-ion battery, the SCiB
(Super Charge ion Battery)
The main features of the standard module, which contains 10 cells, are:
|~ the voltage is 24 volt at 4,2 ampere-hours |
|(so the energy content is 100 watt-hours) |
|~ the battery is very safe (no explosion or fire hazard) |
|~ the charging time is 10 minutes |
|~ the energy density is bad in comparison with an ordinary |
|lithium-ion battery (100 watt-hours at a weight of 2 kilograms |
|and a volume of 1,35 cubic decimetre) |
|~ the lifespan is very large, 10 years or 6000 charging cycles |
|(after 3000 charging cycles the capacity loss will be only 10%) |
|~ the battery can be used within a wide temperature range |
|(-30 to + 45 degrees Celsius) |
|~ the properties of the battery highly agree with those of a |
|super capacitor (high charge and discharge currents and very |
|short charge and discharge times) |
Using this new type of lithium-ion battery, the electric car, the hybrid car and
also the electric bicycle could become a great success. The rapid charging is
especially interesting for recovery of electrical energy during braking and
speed reduction.
Sony also has developed a new lithium-ion battery
The new Sony battery stands out for the large discharge current,
which is possible. Some of the features:
|~ a cell, type 18650 will deliver 1,1 ampere-hours at |
|3,2 volts, so the energy content will be 3,5 watt-hours |
|~ the energy density is 95 watt-hours per kilogram |
|~ the maximum discharge current is 20 amperes |
|~ the battery can be recharged in 30 minutes up |
|to 99% of the capacity |
|~ the lifetime is 2000 charge cycles |
Nexeon announces a lithium-ion cell, with the "highest energy
content in the world"
This concerns the type of lithium-ion cell, that is often used in laptops
and also in the Tesla Roadster. This cell, the 18650, has a diameter
of 18 and a length of 65 millimetres. Some of the features:
|~ the cell provides 3,2 ampere-hours at 3,6 volts, |
|so that is 11,5 watt-hours (compare the cells in the |
|Tesla Roadster, supplying 8,2 watt-hours each) |
|~ the energy density is 275 watt-hours per kilogram |
|~ n the long term even 4 ampere-hours is expected, |
|that is 14,4 watt-hours per cell |
|~ the lifetime is 300 charge cycles |
This may be an interesting breakthrough, for example for use in an electric
bicycle
KIT also announces a new type of battery
Another piece of news mentions a new type of battery, with an energy content
10 times as high as an ordinary lithium-ion battery. Maybe it will ever get
some with electric cars etc.
The graphene super capacitor
The latest news in the field of batteries and super capacitors
is the graphene super capacitor.
Fast charging of a battery
At the fast charging of a battery from the mains, one gets to do with
massive charge currents.
|~ to charge 9,1 kilowatt-hours (= 1 litre of petrol equivalent) in |
|1 hour from 230 volt, a current of 9100 / 230 = 40 amperes |
|will be needed. (efficiencies disregarded). |
|~ if this amount of energy will be charged in 5 minutes in a |
|battery then the current from the mains will be 12 times as |
|large, so 480 amperes. |
So the refuelling of energy in the form of petrol is much easier and
faster than the "refuelling" of electrical energy.
Batteries and accumulators are (still) not very suitable for storing (very) large
quantities of electrical energy, such as is required in an electric car. Even if by
new developments batteries and accumulators will be smaller and lighter, still
the problems remain of charging with very large currents or long charging times.
At a certain amount of energy the product of charging current and charging
time will be constant. At a short charging time, the charging current will be
large. Conversely, a small charging current will expire irrevocably in long
charging times. In this regard the use of fuel cells is less problematic, because
then hydrogen will be refuelled.
The (total) efficiency however, will be significantly worse, and of course the
question remains: "where does the hydrogen come from".
Atomic battery
In an atomic battery energy is released by the decay of radioactive isotopes
and not by a chain reaction.. There are 2 techniques to generate electricity:
thermal conversion
|~ a thermocouple produces a small electrical voltage |
|if heat is applied. A thermocouple is formed by |
|2 different metals connected to each other. |
|~ a hot-air engine starts running if heat is applied |
non-thermal conversion
|~ a capacitor is loaded if radiation, coming from a radioactive source, |
|is beaming on one of the plates. |
|~ radioactive radiation can be converted into infrared light. A photocell |
|can convert this into electricity. |
|~ an electromechanical nuclear battery consists of a fixed metal plate |
|and a bendable plate. Both are isolated from each other. Radioactive |
|radiation creates opposite charges and as a result the bendable plate |
|will move towards the fixed plate until they touch. Then they are |
|discharged and the bendable plate moves back again. This process |
|repeats itself 35 times per second. The movement of the bendable |
|plate is converted into electricity by a piezoelectric material |
Some of the features of the nuclear battery
|~ very expensive |
|~ small size |
|~ low efficiency, up to 8% |
|~ extremely long life, many decades |
|~ very high energy content |
|~ small power |
|~ can work by heat generation or beta radiation |
|as a result of radioactive decay |
|~ applications in the medical sector (pacemakers) |
|~ as an energy source for space vehicles and |
|communications equipment |
|~ in underwater systems and in computerized |
|scientific systems on hard to reach places |
Walking and cycling
For a person of 75 kilograms the basal metabolism will be about 300 kilojoules
per hour. That is 2 kilowatt-hours per day. This amount of energy will be needed
continuously for heartbeat, breathing, maintaining the constant body temperature
(supplementing the heat losses), digestion etc. For example, the energy content
of 1 litre of whole milk is 2700 kilojoules and that will be sufficient for 9 hours
basal metabolism.
|~ approximately 300 kilojoules extra will be needed to walk 1 kilometre |
|~ approximately 60 kilojoules extra will be needed to cycle 1 kilometre |
So walking costs 5 times as much energy as cycling over the same distance
Now the calculation for walking and cycling during the same time
|~ 1 hour walk = 4 kilometres = 4 × 300 = 1200 kilojoules |
|~ 1 hour cycling = 20 kilometres = 20 × 60 = 1200 kilojoules |
So walking will cost the same amount of energy as cycling during the same time
The amount of energy necessary for cycling depends heavily on the bike speed
and the wind. In this example no headwind is assumed and the cyclist is seated
upright. The above figures show how much energy is consumed in the form of
food. The energy content of 1 litre of petrol is 32,6 mega joules.
Conversion to the petrol-equivalent provides the following values:
walking: 1 litre per 108 km cycling: 1 litre per 540 km
A recumbent
The air resistance of a recumbent is about 3 times as small as at a regular bicycle
with an upright seated cyclist. Therefore less energy per kilometre will be needed.
At a speed of 20 kilometres per hour and no wind the petrol equivalent of
a recumbent will be 1 litre per 1235 km
walking:
|~ the mass of a walker is lifted up and down a few centimetres at |
|every step, that takes a lot of energy |
|~ the energy used is proportional to the mass (weight) of the walker |
cycling:
|~ a cyclist is fixated on the saddle and his centre of gravity |
|always remains at the same height. When one leg goes |
|down, the other goes up |
|~ energy is only used for overcoming the air resistance and |
|rolling friction when cycling on a flat road with constant speed |
|The rider's weight is not an issue. (Newton’s 1st Law) |
|~ acceleration and driving up a slope costs extra energy |
|The required energy is proportional to the weights |
|of rider + bicycle. |
The amount of mechanical energy required for cycling 100 km
|~ an upright seated cyclist has to produce a power of approximately |
|75 watts during 5 hours, whilst cycling 20 kilometres per hour and |
|no wind |
|~ so 100 kilometres of cycling requires a quantity of mechanical |
|energy of 75 × 5 = 375 watt-hours |
|~ this equals 1350 kilojoules. |
|~ the efficiency of the conversion of food into mechanical energy |
|is 25% |
|~ so in the form of food 4 x 1350 = 5400 kilojoules will be required, |
|that equals the energy content of only 2 litres of whole milk. |
|~ one doesn't lose weight by cycling 100 kilometres |
|As a result of heat losses one does lose weight from swimming |
|(and especially by eating less!). |
|~ at a headwind of 5 metres per second (= 18 kilometres per hour) |
|3 times as much energy will be needed as when there is no wind. |
Electric bicycle
|~ on an electric bicycle the cyclist is supported by |
|an electric motor |
|~ this motor gets its power from a rechargeable battery |
|~ the degree of support is automatically controlled by |
|a pedal sensor |
|~ the pedal sensor measures the force that is being |
|exercised on the pedals |
|~ the motor gets energy proportional to that force |
|~ the result is, that on a slope or with headwind, |
|support will increase |
Ideally, climbing a slope or cycling against wind will be as easy as cycling on a
flat road without wind. But of course that will cost a lot of energy. Therefore
it is possible at most electric bicycles, to adjust the extent of support more
or less progressively by using a switch on the bicycle handlebar. One can for
example, choose between the modes "normal" or "power". The action radius
of the support is determined by the energy content of the battery and the
energy consumption of the motor.
The legal maximum power of the motor is 250 watts.
Electric bicycles are so constructed that the electric motor can only be enabled,
when one is pedalling. A bicycle with an auxiliary engine in the literal sense of
the word.
The energy consumption of an electric bicycle
The energy consumption of an electric bicycle is strongly depending on the
circumstances under which the bicycle will be used. For example:
|~ 50% support |
|~ an upright seated cyclist |
|~ a speed of 20 kilometres per hour |
|~ a headwind of 4 metres per second |
|~ hard inflated tyres |
Under these circumstances, the energy delivered by the battery will be
5 watt-hours per kilometre
|~ the total efficiency of the charging cycle of the |
|battery and the electricity generation is 30% |
|~ so the primary energy consumption is |
|5 / 0,30 = 16,7 watt-hours per kilometre |
|~ converted to petrol-equivalent this is |
|1 litre per 545 km |
Electric trains
The Double Decker
[pic]
The Double Decker is the most modern and efficient train of the Dutch Railways.
|~ the basic implementation of the train is 4 wagons |
|with 372 seats |
|~ the total length of 4 wagons is 108 metres. |
|~ the weight, including the travellers is 254 tonnes. |
|~ the power is 1608 kilowatts. |
The weight and number of passengers in this train is similar to that of a Jumbo.
In the following, global calculation we will assume an 85% efficiency of the train,
a trajectory of 14 kilometres and a speed of 140 kilometres per hour
(= 39 metres per second).
|~ the maximum power of 1608 kilowatts will be used during |
|acceleration |
|~ the speed of 140 kilometres per hour will be reached |
|in 2,4 minutes |
|~ at that time 3000 metres have been travelled and |
|54 kilowatt-hours consumed |
|~ during the following 9360 metres 1/3 of the power is used |
|~ in the next 4 minutes, at a constant speed, 30 kilowatt- |
|hours are consumed (overcoming the rolling resistance |
|frictional losses and air resistance) |
|~ the remaining 1640 metres will be used for speed reduction |
|and braking |
|~ so the net amount of energy consumed will be 54 + 30 = |
|84 kilowatt-hours (that is some more than the energy the |
|Greenpeace solar panel of 0,75 square meters will generate |
|in a year). |
|~ the total efficiency of the electricity generation and the train |
|together will be 33% × 85% = 28%. |
|~ for a trajectory of 14 kilometres gross consumption will be |
|84 / 0,28 = 300 kilowatt-hours which is equivalent to |
|33 litres of petrol |
|~ this will allow 372 persons to be transported over a distance |
|of 14 kilometres |
|~ which is a consumption of 1 litre per 158 km per traveller |
|~ during the braking of the train, energy can be fed back into |
|the overhead line. |
|~ much extra energy is needed for heating in winter |
|~ that energy should also be supplied via the overhead line |
The results of this calculation come out well in line with the data I got from a
train driver. In a car the heating is provided by waste-heat. On a train energy
for heating is generated with an efficiency of approximately 33%.
The Thalys
[pic]
The Thalys, which runs on the High Speed Line (HSL), consumes much more
energy than an ordinary train. The 1500 volt direct current, as applied in
the Netherlands, will no longer be sufficient.
The Thalys on the line Amsterdam-Paris is suitable for 3 different voltages:
|~ 25000 volts alternating current (on all HSL lines, |
|for this the train has been designed) |
|~ 3000 volt direct current (in Belgium on existing rail) |
|~ 1500 volt direct current (in the Netherlands on existing rail) |
The switching happens automatically. In the Netherlands, the Thalys partially
runs on tracks that already exist. There the speed will be limited to about
160 kilometres per hour especially near Rotterdam and Amsterdam. The train
is equipped with 6 different signalling systems, including the Dutch, Belgian,
German and French system
|~ the Thalys has a fixed composition of 8 wagons |
|2 motor cars with 377 seats. |
|~ its length is 200 metres. |
|~ its weight, including the travellers is 414 tonnes |
|~ its power is 8850 kilowatts. |
In the following global calculation will be assumed that the train will have an
efficiency of 85%. The trajectory will be 100 kilometres and the speed will
be 300 kilometres per hour. (= 83 metres per second)
|~ during acceleration the maximum power of 8850 kilowatts |
|is used |
|~ the speed of 300 kilometres per hour will be reached after |
|3,5 minutes |
|~ at that time than 8 kilometres have been travelled and |
|396 kilowatt-hours consumed |
|~ during the following 92 kilometres 2/3 of the power is used |
|~ than in 18,4 minutes, at a constant speed, 1538 kilowatt-hours |
|will be consumed (for overcoming the rolling resistance, |
|frictional losses and air resistance) |
|~ so the net amount of energy consumed is 396 + 1538 = |
|1934 kilowatt-hours |
|~ the total efficiency of the electricity generation and train |
|together will be 33% × 85% = 28% |
|~ for the entire route of 100 kilometres the gross consumption |
|will be 1934 / 0.28 = 6907 kilowatt-hours |
|~ this is the equivalent to 759 litres of petrol |
|~ this allows 377 persons to be transported over a distance |
|of 100 kilometres |
|~ per traveller this is a consumption of 1 litre per 50 km |
Vessels
Electric boat (seen on an exhibition of boats)
|~ a battery of 420 ampere-hours and 24 volts, so 10 kilowatt-hours. |
|~ this amount of energy is sufficient to sail a boat of 800 kilograms for |
|8 hours at a speed of 6 kilometres per hour. |
|~ the energy costs about € 2,- and for that price 8 persons could be |
|transported over a distance of 50 kilometres. |
|~ converted to petrol-equivalent, that is 1 litre per 91 km per person. |
The fast ferry between Harwich and Hook of Holland
|~ this boat, a Catamaran, with a speed of 75 kilometres |
|per hour is the fastest ferry in the world. |
|~ the boat is powered by 4 gas turbines with a total |
|capacity (power) of 69.000 kilowatts. |
|~ the boat is 124 metres long and 40 metres wide. |
|~ the transport capacity is 1500 passengers and 350 cars |
|~ so the amount of energy consumed is |
|69.000 / 75 = 920 kilowatt-hours per kilometre. |
|~ the consumption is 337 litres of petrol-equivalent per |
|kilometre at an efficiency of 30% of the gas turbines. |
|~ a car weighs on average as much as 12 passengers. |
|~ altogether that is the weight of |
|350 × 12 + 1500 = 5700 passengers. |
|~ this is 1 litre per 17 km per "passenger". |
This ferry has been taken out of service, because there was too little interest
Aircraft
The Boeing 747 “Jumbo"
[pic]
Some global data and calculations:
|~ a Jumbo can carry a maximum of 100.000 litres of fuel per wing. |
|~ the action radius is then 13.500 kilometres. (= 1/3 of the earth's |
|circumference). |
|~ the fuel consumption will therefore be: |
|2 × 100.000 / 13.500 = 15 litres per kilometre |
|~ a Jumbo can carry 450 passengers. |
|~ so the fuel consumption is 1 litre per 30 km per passenger |
|(far more economical than a car with 1 passenger). |
|~ about half of the take-off weight of a Jumbo consists of fuel |
|(on a long distance flight). |
|~ the empty weight is 181 tonnes, the maximum fuel weight is |
|173 tonnes. |
|~ refuelling will take about an hour. That's 200.000 litres in |
|60 minutes = 3.333 litres per minute. |
|~ 200.000 litres = 200 cubic metres. This is the equivalent of a |
|"swimming pool" of 2 metres deep with a surface of 10 by 10 metres. |
|~ the cruising speed at a height of 10 kilometres is 900 kilometres |
|per hour. |
|~ the flight time is 15 hours for the maximum distance of |
|13.500 kilometres. |
|~ so the average fuel consumption of the 4 engines together is |
|200.000 litres per 15 hours. That is a primary energy consumption |
|of 200.000 × 10 kilowatt-hours per 15 hours |
|(1 litre of kerosene = 10 kilowatt-hours) |
|~ this is 40.000 kilowatt-hours per hour useful energy at an |
|efficiency of 30%. A power of 40.000 kilowatts = 40 megawatts. |
|~ the "take off" speed is 290 kilometres per hour. |
|~ within 1 minute the Jumbo is independent of the runway |
|So the (average) acceleration is 1,5 metres / sec2 |
|~ the distance travelled on the runway is 2000 to 2500 metres |
|(depending on the take-off weight) |
The petrol car
The petrol consumption of an average car is 1 litre per 15 km. At a speed
of 120 kilometres per hour, that is 8 litres of petrol per hour. The efficiency
of a petrol engine is heavily dependent on:
|~ the revolutions per minute |
|~ the delivered torque |
|~ the momentary power |
The maximum achievable efficiency is 25% and this is determined by the
compression ratio and the temperature range in the cylinders. (Carnot)
The efficiency of a diesel engine is approximately 35%. A petrol engine
can approach this by:
|~ optimal fuel injection |
|~ optimal oxygen-fuel ratio at all revolutions |
|~ optimal ignition-time at all revolutions |
|~ as many valves as possible |
|~ variable valve timing |
|~ a motor temperature as high as possible |
Hence ever experiments took place with ceramic engines. That would allow a
higher temperature than with engines made of metal. Affecting the efficiency
of the engine in a car is caused by:
|~ the use of the catalyst |
|~ cold start |
|~ variable speed |
|~ variable load |
|~ cooling |
|~ idling |
The electric car
|[pic] |An electric car from 1916 |
Already 5000 electric cars had been manufactured in America by Baker Electric
between 1899 and 1915. The top speed was 23 kilometres per hour, with an
action radius of 80 kilometres. Another well-known brand in the initial phase was
Detroit Electric. This company produced electric cars that reached a top speed
of 32 kilometres per hour, at a 130 kilometres action radius.
A car battery of 12 volt, 36 ampere-hours can provide 12 × 36 = 432 watt-hours
energy. The contents of a normal petrol tank is 48 litres. This corresponds to
437 kilowatt-hours. which is approximately equal to the energy content of
1000 batteries.
Nowadays electric cars can cover reasonable distances. That is due to:
|~ a better kind of battery (nickel-metal hydride or lithium-ion |
|instead of lead batteries) |
|~ the higher efficiency of the electric motor (90%) compared |
|with a petrol engine (25%) |
|~ a lower speed (the air resistance is proportional to the 2nd |
|power of the speed) |
|~ a low rolling resistance, low weight and a streamline |
|~ regenerating of energy during braking, speed reduction and |
|descending a slope |
Some characteristics of the electric car are:
|~ the electric car is virtually silent |
|~ the electric car produces no exhaust gases |
|(but the power plant does all the more) |
|~ there are only a few moving parts, so there is less maintenance |
|~ it is relatively easy to drive the individual wheels separately, |
|so there is no need for a differential |
|~ the primary energy consumption is (slightly) lower than an |
|equivalent car with a petrol engine |
|~ the electric motor can deliver maximum torque at all speeds, |
|this enables a quick acceleration |
|~ the efficiency of the electric motor is high at all revolutions |
|~ the electric motor is never running idle |
|~ there is no need for a gearbox |
|~ the action radius is (very) limited |
|~ the battery is heavy, very expensive and takes a lot of space |
|~ charging the battery lasts very long (minimum 4 hours) |
|~ heating an electric car comes at the expense of the range |
For special applications such as courier services, municipal services
and commuting there may be a future for electric cars in the offing.
It decreases the air pollution in the large cities, however
at the expense of the air pollution at the power plant
The General Motors EV1
[pic]
The General Motors EV1 (electric vehicle) has been produced between 1996 and
1999. It was an electric 2-seater car. 1117 pieces have been produced. They
were not for sale, as they were meant to be for leasing purposes only. In 2003 all
cars were seized and destroyed by General Motors except for a few units, that
were donated to museums and schools. At first they were made unusable. This may
have happened under pressure of the oil industry. The first draft was created on the
occasion of the "World Solar Challenge" in Australia in 1987. The first type, the
"Impact" reached a top speed of 295 kilometres per hour. Everyone was excited,
except General Motors. They started developing the EV-1, to show that time was
not yet ripe for a successful electric car. However, the developers were so excited,
that it was difficult to curb them. The battery of this car could be charged via an
induction coil. This was safe during rainy periods. Slow charging via a plug was
also possible. For the user the EV-1 was a great success. For General Motors the
profit margin was too low and there was fear that the sale of ordinary cars, which
created much profit, would decrease. This happened anyway, because Japan
imported many modern cars. The EV-1 was the best electric car ever made. It was
far ahead of its time.
Some data:
|~ low weight because of an aluminium frame and plastic components |
|~ a very low air resistance |
|~ heating by means of a heat pump |
|~ keyless entry and ignition |
|~ the power of the 3-phase induction motor was 102 kilowatts |
|~ the car accelerated in 8 seconds from 0 to 100 kilometres per hour |
|~ its top speed was 130 kilometres per hour |
|~ the energy content of the nickel-metal hydride battery was |
|26 kilowatt-hours |
|~ the action radius was 200 kilometres |
|~ the average energy consumption was 130 watt-hours per kilometre |
|~ the load time of the battery was 8 hours |
A film has been made about this car in 2006: "Who killed the electric car?"
The Tesla Roadster
[pic]
In 2008, a 2-seater electric sports car was introduced, the Tesla Roadster
Some data:
|~ the power of the 3-phase induction motor is 215 kilowatts |
|~ the efficiency of the motor is 92% |
|(virtually independent of the speed) |
|~ the car accelerates in 4 seconds from 0 to 100 kilometres per hour |
|~ then the acceleration is 0,7 g (g = the acceleration of gravity) |
|~ the top speed is 200 kilometres per hour |
|~ the energy content of the lithium-ion battery is 56 kilowatt-hours |
|(that is equivalent to 6,1 litres of petrol) |
|~ the battery consists of 6831 "laptop" cells (type 18650), which |
|are cooled liquidly |
|~ the energy content of 1 cell is 8,2 watt-hours |
|~ the energy density of the battery is 121 watt-hours per kilogram |
|(including housing) |
|~ the action radius is 340 kilometres (at a constant speed of 100 |
|kilometres per hour) |
|~ at this speed the energy consumption of the electric motor is |
|56.000 / 340 = 165 watt-hours per kilometre |
|~ the total efficiency (“plug-to-wheel”) of the car is 88% |
|~ so the energy consumption from the outlet is |
|165 / 0,88 = 188 watt-hours per kilometre |
|~ the total efficiency of the production of electricity is 33% |
|~ so the primary energy consumption is |
|188 / 0,33 = 567 watt-hours per kilometre |
|~ converted to petrol-equivalent one arrives at 1 litre per 16 km |
|~ the weight of the car is 1240 kilograms |
|~ the minimum loading time of the battery is 4 hours |
The quick acceleration is due to the fact that the electric motor delivers a constant
torque on the entire range from 0 up to 6000 revolutions per minute.
The Mechanics teaches that the same amount of energy is needed for fast or slow
acceleration to the same end-speed. At a constant speed on a flat road, the weight
of the car hardly is important. During acceleration and climbing a slope the weight
is indeed important. But while braking, speed reduction and descending a slope, in
proportion to the weight more or less energy will be recovered.
The Tesla model S
[pic]
In 2013 a 5-seater electric car was introduced in Europe, the Tesla model S
Some data:
|~ the power of the 3-phase induction motor is 270 kilowatts |
|~ the efficiency of the motor is 92% |
|(virtually independent of the speed) |
|~ the car accelerates in 5,6 seconds from 0 to 100 kilometres per hour |
|~ then the acceleration is 0,5 g (g = the acceleration of gravity) |
|~ the top speed is 200 kilometres per hour |
|~ the energy content of the lithium-ion battery is 85 kilowatt-hours |
|(= 9,3 litres of petrol-equivalent) |
|~ the action radius is 480 kilometres (at a constant speed of |
|88 kilometres per hour) |
|~ at this speed the energy consumption of the electric motor is |
|85.000 / 480 = 177 watt-hours per kilometre |
|~ the total efficiency ("plug-to-wheel") of the car is 88% |
|~ so the energy consumption from the outlet is |
|177 / 0,88 = 201 watt-hours per kilometre |
|~ the total efficiency of the production of electricity is 33% |
|~ so the primary energy consumption is |
|201 / 0,33 = 610 watt-hours per kilometre |
|~ converted to petrol-equivalent one arrives at 1 litre per 15 km |
|~ the weight of the car is 2100 kilograms |
|~ at home the loading time of the battery is about 8 hours |
|~ with a supercharger the battery can be loaded to 80% in 40 minutes, |
|that requires 0,8 × 85 = 68 kilowatt-hours |
|~ the supercharger delivers direct current directly to the battery. With |
|special cables the loading equipment in the car is bypassed. |
|~ initially the direct current is 200 amperes at a voltage of 380 volts |
|(76 kilowatts). The current slowly decreases to 125 amperes, |
|until 80% loading is reached |
|~ the superchargers are built along major highways |
|In the Netherlands there are already 2 pieces. |
The Opel Ampera
[pic]
A new interesting development is the Opel Ampera. This is a 4-seater car which
meets with the problem of the long charging time of a battery and the limited range
of the electric car. The "Ampera" will be launched around 2012 and will be
equipped with a "charging engine". The energy content of the battery will be
sufficient for an action radius of 60 kilometres. The charging engine is only intended
to load the battery when it gets empty during a long ride. Thus the action radius will
be increased up to 500 kilometres. This will make the applicability of this electric
car more attractive. Although the entire concept does not save any energy, at a well
planned use, on short distances (commuting) one never needs to fuel the tank, while
the risk of an empty battery will be avoided. The charging engine works at a
constant speed, with maximum efficiency. The "Ampera" is solely propelled by the
electric motor. The charging engine has the sole task of charging the battery, when it
is drained during a long ride.
Some data:
|~ the power of the electric motor is 110 kilowatts |
|~ the car accelerates in 9 seconds from 0 to 100 kilometres per hour |
|~ its top speed is 160 kilometres per hour |
|~ the energy content of the lithium-ion battery is 16 kilowatt-hours |
|(= 1,8 litre petrol-equivalent) |
|~ the action radius without recharging is 60 kilometres |
|~ the action radius together with the charging engine is 500 kilometres |
|~ the power of the charging engine is 60 kilowatts |
The hybrid car
|[pic] |The Prius |
In 1997 Toyota has launched the "Prius". This is a "hybrid" car. In 2004 an
improved version appeared. Worldwide there are now (2013) more than 3 million
cars of this type. It is a car which is propelled by an electric motor (60 kilowatts),
a petrol engine (73 kilowatts) or a combination of both, depending on the situation.
Its goal is to achieve an as high as possible (vehicle) efficiency.
|~ the efficiency of the (Atkinson) petrol engine is high, but strongly |
|depending on the load and the speed |
|~ the electric motor always has a high efficiency |
|~ the electric motor is working when the efficiency of the petrol |
|engine is low |
|~ the energy for the electric motor is supplied by a rechargeable |
|nickel-metal hydride battery of 1,3 kilowatt-hours |
|(= 0,14 litres of petrol-equivalent) |
|~ at (regenerative) braking and speed reduction the electric motor |
|works as a dynamo and delivers energy back to the battery |
|~ in addition, the battery is recharged by a generator, which is |
|linked to the petrol engine |
|~ the charging happens, when the petrol engine works with a high |
|efficiency |
|~ the generator can also provide energy directly to the electric |
|motor |
|~ the petrol engine, generator and electric motor are linked |
|together by means of a mechanical energy distributor, which is |
|controlled by a microprocessor |
|~ this energy distributor also functions as a continuously variable |
|automatic transmission |
|~ the efficiency of this automatic "gearbox" is much higher than an |
|ordinary manual gearbox. |
The hybrid system can of course never be more energy efficient than the
petrol engine which is part of it.
All energy is derived from this engine and all energy conversions are accompanied
with (small) losses. The profit of the hybrid system is extracted from the following
properties
|~ the electric motor works during starting from standstill and |
|at low speeds |
|~ the petrol engine is designed for the average power and |
|therefore it will be extra economical. |
|~ the electric motor assists the petrol engine during acceleration |
|and short-term at high speeds. |
|~ energy is returned to the battery when speed is reduced and |
|while braking. |
|~ the petrol engine stops once the car is stationary and so |
|never idles. |
|~ the petrol engine works as much as possible under |
|circumstances when the efficiency is high. |
|~ at low efficiency of the petrol engine the electric motor assists. |
In braking-stopping-acceleration situations the highest effect of the hybrid system
is achieved. For instance in traffic jams and in cities with many traffic lights. Over
long distances and at high speed the hybrid system is not working. Then only the
economical (Atkinson) petrol engine works. The efficiency of this engine is 34%.
A normal petrol engine has an efficiency of 25%. The Prius (a luxury 5-seater car),
with an "energy monitor" on the dashboard, invites you to practise an economical
driving style. The consumption then will approach the 1 litres per 25 km
provided by Toyota.
The fuel cell car
Some characteristics of the fuel cell car are:
|~ the energy source for a fuel cell car is hydrogen gas |
|~ in a fuel cell the hydrogen gas is “burned”, as a result |
|electricity is generated |
|~ at the combustion of hydrogen no harmful gases arise, |
|just water |
|~ the generated electricity is fed through a battery to an |
|electric motor which propels the car |
|~ while braking and speed reduction energy is returned |
|to the battery |
The question remains: "where does the hydrogen come from".
Hydrogen can be obtained by electrolysis (decomposition) of water.
The electric energy needed for the decomposition of the water must be
generated through combustion of fossil fuels (which causes harmful
gases), nuclear energy, wind energy or other forms of "green" energy
Hydrogen can also be extracted from crude oil or natural gas. It is said
Shell will try to produce this in the near future. But that will cost fossil fuel.
Efficiencies
|~ the efficiency of the generation of electricity is 33% |
|~ the efficiency of electrolysis of water is 80% |
|~ the efficiency of a fuel cell is 50% |
|~ the efficiency of an electric motor is 90%. |
So the car that runs on hydrogen, will be no solution to the
energy problem. The total efficiency is only 12%
(33% × 80% × 50% × 90% = 12%)
The energy consumption of the fuel cell car, converted to petrol
equivalent, is about 1 litre per 8 km
According to Toyota, hybrid fuel cell cars cannot be launched on a large scale
before 2015. Some prototypes of this brand are already on the road. A 5-seat
car, type FCHV-4 (Fuel Cell Hybrid Vehicle) with a maximum speed of 150
kilometres per hour. The fuel is pure hydrogen in a high-pressure tank, at a
pressure of 35 atmospheres. Introduction of the fuel cell car requires an
infrastructure that makes possible, that in many places (the very explosive and
therefore dangerous) hydrogen gas under high pressure, can be tanked. The
applied fuel cell has a capacity of 90 kilowatts. The energy goes via a nickel-
metal hydride battery to an 80 kilowatts electric motor.
The latest news in the field of fuel cell cars is the development of the FINE-N. In
this car each of the 4 wheels will be powered by an electric motor. As a result, no
differential will be necessary anymore, which will result in better vehicle efficiency.
The modular structure of the vehicle offers new possibilities for the design, because
there will be no engine in the nose. In addition, the fuel cell can be placed anywhere
in the vehicle in principle.
Will the fuel cell car ever appear on the road?
It is very unlikely that the fuel cell car ever will appear on the road. It is more
obvious, that in future cars will drive on synthetic petrol, synthetic diesel oil or
electricity.
Instructive toy
A working system of a fuel cell car in the form of a instructive toy is for sale for
€ 99,- It includes a solar cell, a reactor for the production of hydrogen by means
of electrolysis of water and a fuel cell car.
Toyota
It is striking, that especially Toyota is very active with the development of "green"
cars on all fronts. All are full 5-seater cars without any compromise in the area of
safety and luxury. For years they have been tested and applied in practice on a
large scale
|~ the electric car |
|~ the hybrid car (Prius) |
|~ the fuel cell car |
The production of the electric car has been discontinued, because of low interest.
Toyota now produces an assortment of 4 hybrid cars, 1 plug-in hybrid car.
In 2015 Toyota will launch the first fuel cell car, the FINE-N
Honda, as well as Toyota a pioneer in the field of hybrid cars, is now launching
the "Insight", after the hybrid version of the "Civic"
Volkswagen says the hybrid car is an "ecological disaster", because it contains a
large battery. Nevertheless, it is also concerned with the development of a hybrid
car, "because there is a demand for such a car". If the allegation of Volkswagen
would be correct, then the electric car should be a major disaster, because it
contains a very large battery.!
BMW has let us know to refrain from the development of the fuel cell car for the
time being. They will however develop an internal combustion engine that will run
on hydrogen. The efficiency of this engine would be about 50%.
Opel describes the Prius as "technologically prehistoric". (the grapes are very
acidic). The market introduction (in 2011) of the Ampera has been postponed
because of problems with the lithium-ion battery. (spontaneous combustion).
The "Hydrogen Economy"
The energy scenario of the future, when the fossil fuels will be exhausted, may be
(partially) based on the so-called hydrogen economy. Hereby it is assumed that
an endless amount of "green" energy will be available around 2050. Solar energy
(from the Sahara) and wind energy (submitted by wind farms in sea) are not
available continuously. (the sun does not shine at night and the wind is not always
blowing). Thus for the electricity generated by these "green" energy sources, there
is a storage problem. It is possible to use electricity for the production of hydrogen
by electrolysis (decomposition) of water. Unlike electricity, hydrogen can be stored
under very high pressure, both in unlimited quantities and during long periods of
time. Transport could take place through a network of pipelines to tank stations,
although huge practical problems will arise. It seems more obvious to produce
hydrogen onsite at tank stations. The hydrogen can deliver electricity via fuel cells
where the only "combustion" product is water. In this scenario hydrogen is an
energy carrier
Some people think hydrogen is an inexhaustible source of energy, but
it's not. On the contrary. Producing hydrogen by electrolysis of water
will cost 1,25 times more energy than it will deliver.
In the media usually the "evidence" of the inexhaustibility is suggested by showing
the sea in the background which is nonsense of course, because water contains no
energy. First it must be decomposed into hydrogen and oxygen. The hydrogen
economy provides the following image:
"green" energy > electrolysis of water > hydrogen > fuel cell > electricity
Storing electrical energy in a battery is accompanied by a efficiency of 75% - 90%
(charging cycle) Storing electrical energy in hydrogen is much less effective. The
efficiency of electrolysis of water is 66% and of the fuel cell is 45%. This will result
in a total efficiency of 30%. Hydrogen as a storage medium of energy only seems
useful for vehicles, when the oil is exhausted and if there has still been no
breakthrough in battery technology. Also it is conceivable that the atomic battery
ever might be a solution.
Comparison petrol – hydrogen
Comparison of the CO2 emissions of a gasoline engine and at the production
of hydrogen gas for a fuel cell in which an electric motor is connected
The hydrogen is produced by electrolysis of water, with electricity provided
by a gas-fired plant.
Petrol
|~ the energy content of 1 litre of petrol is 9.1 kilowatt-hours |
|~ at the combustion of 1 litre of petrol the CO2 emission will |
|be 3,1 kilograms "well-to-wheel" |
|~ the efficiency of a petrol engine is 25% |
|~ so the useful labour will be 9,1 x 0,25 = 2,3 kilowatt-hours |
|~ the CO2 emissions per kilowatt-hour will be |
|3,1 / 2,3 = 1,4 kilograms |
Hydrogen
|~ the energy content of 1 kilogram of hydrogen is 33,6 kilowatt-hours |
|~ at an efficiency of 80% the production of 1 kilogram of hydrogen |
|by means of electrolysis will cost 33.6 / 0.8 = 42 kilowatt-hours |
|~ producing 42 kilowatt-hours by means of a gas-fired plant creates |
|32 kilograms CO2 |
|~ the efficiency of a fuel cell + electric motor is 45% |
|~ so the useful labour will be 33,6 x 0,45 = 15,1 kilowatt-hours |
|~ the CO2 emissions per kilowatt-hour will be: |
|32 / 15,1 = 2,1 kilograms |
Natural gas and petroleum products, such as diesel oil and petrol, are chemical
compounds of carbon and hydrogen. These so-called hydro-carbons are, unlike
pure hydrogen, very well manageable. Energy will be released by incineration of
both the carbon and hydrogen. Carbon dioxide (CO2) and water (H2O) are
formed respectively
The production of hydrogen using nuclear energy may take place via a thermo
chemical process or through electrolysis of water. However, the ideal solution is to
produce hydrogen using "green" energy. The potential of economically extractable
"green" energy is (very) little and the conversion to hydrogen is particularly
inefficient. Of course it is possible to produce hydrogen from fossil fuel, but that
was precisely not the intention because we are running out of fossil fuels.
There are quite a few misunderstandings about water, hydro power, hydrogen
and nuclear fusion of hydrogen-isotopes. Therefore the following overview:
Water
Water is the combustion product of hydrogen and oxygen. So it contains
no energy
Hydro power
When fast running water or water under high pressure drives a turbine, hydro
power is released. This happens in a hydroelectric power plant. Hydro power
is an energy source
Hydrogen gas
Water can be decomposed into hydrogen and oxygen by electrolysis. The energy
in hydrogen is released again at the "burning" in a fuel cell. The energy for the
decomposition of water initially has to be provided by fossil fuels, nuclear energy,
nuclear fusion, wind energy, hydropower, geothermal energy or solar energy. (so
by energy sources). Therefore hydrogen is not an energy source but an energy
carrier.
Nuclear fusion of hydrogen isotopes
Trough nuclear fusion hydrogen isotopes can fuse into helium. A huge amount of
energy is then released. This technique is still in its infancy and it will be at least
50 years before there may be practical applications.
Nuclear fusion is an energy source.
Some quotes from letters in “NRC-Handelsblad”
The promise that in future hydrogen will be the solution for the energy supply for
mankind, is based on pure fantasy. Not technically. It works: the hydrogen engine,
the fuel cell and also the windmills or the solar cells that might deliver the energy
needed for the electrolysis of water to produce hydrogen.
Without any quantification, about the potential of the said technique, this kind
of stories fits into the popular magazines of the car lobby, not in the NRC.
The biggest objection against the use of hydrogen as a fuel in cars is that it is very
unsafe. Both at the distribution trough pipelines and when driving a car safety is
bad. At application of electrolysis using electricity produced in a natural gas-fired
power plant, the chain is:
natural gas > electricity > hydrogen > electricity > propulsion energy
One would really come up with the idea to drive cars on natural gas and to forget
hydrogen
Nuclear fusion
There are 2 types of nuclear reactions, suitable for the generation of energy.
|~ fission of uranium nuclei. This is called nuclear energy |
|~ fusion of hydrogen nuclei. This is called nuclear fusion |
Mass loss happens in both processes. In nuclear fission, this is about 0,10% and in
nuclear fusion 0,35%. The "disappeared" mass is converted into energy according
to the formula of Einstein
The energy that the sun radiates comes from nuclear fusion of hydrogen atoms.
This nuclear fusion is formed at an extremely high pressure and a temperature of
15 million degrees Celsius. In nuclear fusion on Earth the pressure is negligible in
comparison with the Sun and therefore the temperature here should be very much
higher, around 150 million degrees Celsius.
If matter is very strongly heated, it forms a plasma. In a plasma the atomic nuclei
and electrons move separately. Atomic nuclei are positively charged and repel. The
repellent force is overcome at 150 million degrees by the speed of the movement
of the atomic nuclei. As a result nuclear fusion occurs
The fusion reaction which can best be established on Earth is the merging of the
hydrogen isotopes Deuterium and Tritium. This produces Helium atoms, neutrons
and very much energy. Fusion of a Deuterium-Tritium mixture with a mass of 250
kilogram generates as much energy as the incineration of 2,7 million tonnes of coal
That is sufficient to keep a power plant of 1000 megawatts running at full power
for one year.
The main problem with fusion is the extremely high temperature, which is needed
in the plasma. No material is resistant to this extreme temperature. In a so-called
"Tokamak" the hot plasma is trapped in a strong magnetic field and there is no
contact with the wall. A Tokamak is a ring-shaped reactor where the plasma is
heated up to the temperature at which fusion occurs.
To deliver more energy than necessary for the merging process a Tokamak must
have a minimum size. This will be realized for the first time in ITER (International
Tokamak Experimental Reactor), the first (experimental) fusion power plant. The
outer dimensions are: 24 metres high and 34 metres in diameter. ITER is a project,
which Reagan and Gorbachev have taken the initiative for at the end of the cold
war. ITER must demonstrate the possibility of long-term energy generation with
nuclear fusion. It is expected that during 10 minutes 500 megawatts can be
generated. This is ten times more than the amount of energy that is used for
maintaining the hot fusion plasma. ITER is the biggest international scientific
research project since the construction of the International Space Station. (ISS)
After ITER a larger power plant DEMO will be built. That should demonstrate
the technical feasibility, reliability and economic attractiveness of fusion energy
Around 2050 the first prototype of a commercial fusion reactor PROTO should
be ready. Nuclear fusion is inherently safe. There is no chain reaction. If something
goes wrong, the reaction will stop. Because there is no chain reaction, nuclear
fusion is inherently safe. In nuclear fusion little radioactive waste arises. This waste
has a short half-life time.
Source: "Kernfusie, een zon op aarde" ("Nuclear fusion, a Sun on Earth")
Author: Dr. Ir. M.T. Westra FOM-Institute for plasma physics "Rijnhuizen".
Press release on 21 November 2006:
"The European Union, the USA, Russia, China, India, Japan and South Korea
have reached an agreement on the construction of the first fusion power plant.
The construction (of ITER) begins in 2008 in the South-French Cadarache and
it will take 10 years. "
Nuclear energy
The relationship between mass and energy can be calculated with
the formula of Einstein.
|1 kilogram-mass is equivalent to 25 billion kilowatt-hours |
E = mc2
E = energy m = mass c = the speed of light
The fuel for the nuclear power plant in Borssele consists of 4,5% fissile
Uranium 235. Approximately 1 per thousand of the mass will be converted
into energy during the fission process. The energy per kilogram of nuclear
fuel as heat released will be "only" 1,2 million kilowatt-hours.
In 2008 the electricity consumption in the Netherlands was 109 billion
kilowatt-hours
This would require: (rounded)
|either |250 tonnes |enriched Uranium |(efficiency 33% |
|or |31.000.000 tonnes |coal |(efficiency 40%) |
The difference in efficiencies is the result of the fact that a nuclear power plant
works with lower temperatures (by application of heat exchangers), than a gas,
oil or coal-fired power plant. (Carnot).
Imagine a train with 50 tonnes goods wagons and a length of 12 metres each,
then the following image will appear:
|~ for the carriage of enriched Uranium: 5 goods wagons = 60 metres |
|~ for the carriage of coal 620.000 goods wagons = 7440 kilometres |
From the combustion of all that coal 81 million tonnes of carbon dioxide
(CO2) will be released. (so that is only in the Netherlands and only for the
benefit of electricity generation)
In 2008 the total primary energy consumption in the Netherlands
was 927 billion kilowatt-hours
The equivalent of this is approximately 100 billion litres of petrol, a cube with
an edge of 460 metres. Obviously sustainable energy is not an option for the
time being.
|~ the stock of fossil fuels is large, but finite. (in about 50 years all |
|economically extractable fossil fuels except coal will be exhausted) |
|~ the environmental pollution at the combustion of fossil fuels is very high |
|~ renewable energy will never be sufficient, because there are more and |
|more people, with still more energy needs. In China with 1351 million |
|inhabitants, electricity consumption has increased with 715% in the |
|period from 1990 to 2011 |
From 1990 to 2006 the increase of world population has been 24%
From 1990 to 2006 the increase of world energy consumption has been 36%
Summary:
|~ the world’s population and the energy consumption are increasing rapidly |
|~ natural gas and oil resources will be exhausted at the end of this century |
|~ sustainable energy will never meet the requirements of 9 billion earthlings |
Conclusion:
|~ coal-fired power plants and nuclear energy will be inevitable |
Some people think:
|~ they will solve it somehow |
|(they “simply” fill the Sahara with solar panels) |
|~ It will outlast my time |
|(this remains to be seen and what about the offspring?) |
|~ In the long term all energy will be generated "sustainable” |
|(all the energy needed for heating, food production, industry |
|aircraft, trains and 1 billion cars?) |
Anything can be calculated, but that does not mean that it can
be achieved in practice, or that it is economically feasible
For example:
|~ the amount of solar energy which is irradiated annually on the Earth |
|is 8000 times more than the annual world energy consumption. |
|~ in 2009 only 0,1% of the world production of electricity consisted |
|of solar energy |
It takes a long time before the clean nuclear fusion will take place. More than
half a century scientists are already working on it. The most optimistic estimate
is, that in 2050 the first nuclear fusion reactor will be operational for commercial
use. At that time practical results will be necessary because the stock of fissile
Uranium for the existing type of nuclear power plants is limited and only will
be sufficient for the forthcoming 75 years (at the current rate of consumption).
Breeder reactors, where nuclear fuel is handled 60 to 100 times more efficient
may not be realized as a result of the environmentalists obstruction. (Kalkar)
On the internet I found the following message of ECN (= Energy research
Centre Netherlands):
"New nuclear fuel reduces radioactive waste".
“Thorium is an interesting fuel, because the Thorium inventory on Earth is
sufficient for some thousands years. The radiotoxity of Thorium is a factor
10 to 100 times lower at all stages of the cycle than Uranium"
Opponents of nuclear energy say "that it cannot be applied". The opposite
has been proven in our neighbouring countries. The nuclear energy's share
of electricity generation is
France 77% Germany 23% England 14%
Belgium 54% Switzerland 41% Sweden 43%
Hypocritically in the Netherlands the share of nuclear energy is limited to 4%
and then the missing is imported from France, Belgium and Germany. The
amount of imported nuclear energy is 2 times as much as is generated in
the Borssele nuclear power plant
Worldwide 13,4% of all electrical energy is generated by nuclear energy.
By environmentalists the importance of nuclear energy is invariably downplayed,
while hydropower is stepped up as a very important energy source.
The reality is, that worldwide the share of nuclear energy is almost as
large as the share of hydropower
Press release on 13 October 2009:
"Belgium keeps its nuclear power plants 10 years longer open than originally
planned. That the Energy Minister has announced. The plants would actually
close in 2015, they remain now open until 2025. because of the benefits for
the Belgian Treasury".
Press release on 1 January 2010:
The only nuclear power plant in Lithuania is decommissioned. Lithuania
promised the conclusion in 2004 in exchange for accession to the European
Union. The power plant is a larger version of that at Chernobyl. For Lithuania
it means that a cheap source of energy is lost and now one becomes dependent
on natural gas from Russia. The nuclear power plant provided almost three-
quarters of the Lithuanian energy requirements.
Dutch Teletext 30 May 2011
Germany will terminate nuclear energy. The 17 German nuclear plants will shut
down in 2022. The 7 reactors that have been closed after the nuclear disaster
in Fukushima will remain closed permanently.
Dutch Teletext 27 June 2011
France invests a billion euro in the development of secure methods for exiting
nuclear energy. President Sarkozy says that it is not an option for France to
stop nuclear energy
Dutch Teletext 13 July 2011
The Japanese premier Kan no longer wants to use long-term nuclear energy.
The disaster in Fukushima in March this year has made him aware of the risks
of nuclear energy. According to the Prime Minister, Japan needs to use
sustainable energy sources.
Dutch Teletext 11 April 2014
However Japan would continue to use nuclear energy.. Prime Minister Abe
writes in the first note since the disaster at Fukushima that nuclear power brings
stability to energy supplies. Abe`s predecessor wanted to go winding down.
Until 2011 30 percent of the energy was generated in nuclear power plants.
Japan hardly has natural resources and imports much oil and natural gas.
Concerning nuclear energy: each solution has its advantages and disadvantages
("the law of conservation of misery")
The question is: which is preferably?:
|~ irreversible climate change |
|~ sea level rising and flooding of the land |
|~ continued increase in air pollution (CO2) |
|~ exhaustion of all fossil fuels |
|~ environmental disasters involving oil tankers, |
|oil rigs and oil drilling at sea, such as: oil spill in |
|Alaska, the Gulf of Mexico and in the Niger delta |
|~ wars to secure the supply of oil or natural gas |
|~ earthquakes and subsidence by gas extraction |
or
|~ a limited (radioactive) waste problem, which can |
|be solved in principle |
|~ accidents with nuclear plants (Harrisburg 1979, |
|Chernobyl 1986, Fukushima, 2011) |
This dilemma exists, because before the year 2050 it seems to be necessary, that
an extra 2 billion people still have to come. On average this meansC:\Users\Arthur\Documents and Settings\Jan\Mijn documenten\e-facts" l - increase 1 million
extra per week, while already there are 7 billion earthlings. Often it is said, that
radioactive waste from nuclear power plants remains active for 240.000 years.
This argument is not very interesting. I dare to the theorem, that within this period
humanity will have died out. Perhaps by nuclear weapons
It is curious that one is excited about nuclear energy and not about nuclear
weapons
Message in NRC-Handelsblad of 17 September 2010
The American president Obama is an important step closer to ratification of a
Treaty with Russia on reducing strategic nuclear weapons. Whether the Senate
will ratify that Treaty is by no means certain. Under the Treaty, the USA and
Russia will shrink their strategic nuclear warheads to 1550 pieces each in
seven years. Around 30 percent less than now is permitted
Dutch Teletext 23 December 2010
In the U.S. Senate a majority has approved the new START Treaty. The Treaty
should lead to less strategic nuclear weapons in the USA and Russia. The Russian
Duma has yet to accept. The approval in the Senate is a victory for Obama. Last
year he received the Nobel Peace Prize for his pursuit of a world without nuclear
weapons
Dutch Teletext 16 February 2012
The American government considers a drastic reduction of the number of nuclear
weapons, perhaps with 80%. That is much more than was agreed in the new Start-
Treaty with Russia. Than only 300 nuclear weapons would remain.
Many people oppose against nuclear energy, because they "fear" that their offspring
(in thousands of years) will be stuck with the problem of radioactive waste.
Nevertheless, these same people are consuming all fossil fuels that are still available
in record pace, without putting themselves to any restrictions. The next generation
should help themselves. Of course these same people will think more carefully
balanced about nuclear energy, as it will become clear that their own energy
supplies will be in danger.
Problems with nuclear power are:
|~ the safety of nuclear reactors |
|~ the safe storage of radioactive waste |
|~ the danger of proliferation of nuclear weapons |
Thorium as nuclear fuel might be a possibility to switch to worldwide. This does
not show the above mentioned problems or at least to a much lesser extent.
A strong cuts in the energy consumption might be a slowing factor for the
introduction of nuclear energy. Unfortunately this will not work.
Everyone thinks it's just:
delicious meat, greenhouse vegetables, frozen foods, from the
tropics argued fruit
fun flight and car holidays, many children, the TV
(which is switched on the whole day)
easy the car, refrigerator, washing machine, dryer, microwave
nice and warm central heating
nice and cool air conditioning
Some facts, calculations, and things worth knowing
Energy consumption in the Netherlands in the year 2008
|~ In 2008 the average electricity consumption per household |
|was 3560 kilowatt-hours |
|~ In the Netherlands there are 7 million households. So the total |
|electricity consumption was 25 billion kilowatt-hours |
|~ The total electricity consumption, industry, agriculture and |
|public transport included was 109 billion kilowatt-hours |
|~ At 40% efficiency 273 billion kilowatt-hours of primary |
|energy was required |
|~ The total primary energy consumption, necessary for heating, |
|industry, cars and generation of electricity was |
|~ 927 billion kilowatt-hours |
|~ That is 3,4 times as much as the primary energy needed for |
|the generation of electricity |
The overall efficiency of the production and transport of
electricity up to the outlet
|~ the electric power plant 40% |
|~ the electricity transport via high-voltage lines 95% |
|~ the transposition of the high voltage to low voltage 95% |
|~ the electricity transport via the low-voltage grid |
|to the outlet of the consumer 92% |
So the overall efficiency is 40% × 95% × 95% × 92% = 33%
The overall efficiency of the production and transport of
petrol up to the petrol pump
|~ pumping out the oil source 97% |
|~ transport to the refinery 99% |
|~ the refining process 85% |
|~ transport to the petrol pump 99% |
So the total efficiency is 97% × 99% × 85% × 99% = 80%
The mass-energy equivalent
|~ E = mc2 (Einstein) |
|~ m = 1 kilogram-mass, that is the amount of mass that |
|weighs 1 kilogram on earth |
|~ c = the speed of light = 3 × 108 metres / second |
|~ c2 = 9 × 1016 metres2 / second2 |
|~ E = 1 x 9 × 1016 joule = 90000 × 109 kilo joule |
|~ 1 kilowatt-hour = 3600 kilojoules |
|~ E = (90000 × 109) / 3600 = 25 billion kilowatt-hours |
So:
|1 kilogram-mass is equivalent to 25 billion kilowatt-hours |
The Sun
Almost all energy on earth comes from the Sun
Almost all energy resources on Earth (oil, natural gas, coal, biomass, wind
and hydro power) find their origin in solar energy.
Exceptions are: geothermal energy, nuclear energy and energy from the
moon. (tidal energy). The most direct source of energy is the light and heat
radiation from the Sun. This energy source is clean and inexhaustible and
in the distant future we will be largely dependent on it. The energy that is
radiated by the Sun is generated by nuclear fusion
Every second 4,27 billion kilogram-mass in the Sun turns into energy
Nuclear fusion on Earth may also play a large role in energy generation.
Calculation of the amount of energy radiated by the Sun in 1 second
|~ the distance between the Earth and the Sun is 150 million kilometres |
|~ the radiation power of the Sun is 1,36 kilowatt per square meter on |
|earth. (that is the solar constant, measured outside the atmosphere) |
|~ the total radiation power from the Sun is: the solar constant multiplied |
|with the surface of a sphere with a radius of 150 million kilometres |
|~ the radius of the sphere r = 150 × 109 metres |
|~ the surface of the sphere = 4 π r2 = 4 π × 1502 × 1018 square meters |
|~ the total amount of energy emitted from the Sun in 1 second is: |
|1,36 × 4 π × 1502 × 1018 × 1 kilowatt-seconds |
|~ 1 kilogram-mass = 25 × 109 × 3600 kilowatt-seconds |
|~ the amount of energy radiated by the Sun in 1 second is equivalent: |
|to: (1,36 × 4 π × 1502 × 1018 × 1) / (25 × 109 × 3600) = |
|4,27 billion kilogram-mass |
In 2008 the electricity consumption in the Netherlands was 109 billion
kilowatt-hours. That is equivalent to 4,36 kilogram-mass. The amount
of energy the Sun radiates in 1 second is 1 billion times as much
as the total use of electricity in 1 year in the Netherlands
The total amount of solar energy irradiated on the Earth
|~ the total amount of radiant energy is equal to what falls |
|perpendicular on a circular plane with the radius of the |
|Earth (the radius r = 6400 kilometres). |
|~ the surface of that circular area is π r2 = |
|3,14 × 40 × 1012 square meters. |
|~ the sun shines 8760 hours per year on this imaginary plane, |
|with an intensity of 1 kilowatt per square metre. |
|~ so the total amount of annual irradiated energy is |
|3,14 × 40 × 1012 × 8760 × 1 = 11.000 × 1014 kilowatt-hours |
|~ the annual world energy consumption amounts |
|1,42 × 1014 kilowatt-hours |
So the amount of annual irradiated energy is 8000 times as much as the
annual world energy consumption and equivalent to a quantity of petrol,
which fills a cube with an edge of 50 kilometres. One can also say:
The amount of 1 hour of solar-energy is approximately equal to the annual
world energy consumption.
Some people conclude from this that an energy problem doesn't exist.
However, one must bear in mind the following
:
|~ a large part of the radiant solar energy is stopped |
|by the clouds. |
|~ for the generation of solar energy gigantic surfaces |
|are needed. see: Waldpolenz Solar Park |
|~ to replace a 600 megawatt power plant by solar |
|panels, in the Netherlands an area of 100 square |
|kilometres will be needed |
|~ there is no efficient large-scale system for the |
|storage of solar energy |
|~ the Earth's surface consists for 71% of water |
|~ the remaining 29% is distributed as shown below |
[pic]
Some properties of light
|~ Light travels (rectilinear) by means of electromagnetic |
|waves. (and not through "ether waves") |
|~ Light reaches an observer always with the speed of light. |
|(in vacuum). It does not matter if a light source (e.g. a Star) |
|moves relative to the observer, or that the observer moves |
|relative to the light source. The mutual speed between the |
|light source and the observer has no influence. |
|~ The speed of light (in vacuum) is always relative to an |
|observer in all directions 300.000 kilometres per second |
|and therefore it will be marked with the letter c (= constant) |
Does ether exist?
The earth rotates in an orbit around the Sun with a speed of 30 kilometres per
second. Formerly one thought that the whole universe was filled with "ether"
and that light was propagated by ether-waves. The consequence would be
that the speed of light measured on Earth depends on the movement of the
Earth in relation to the ether. (in analogy with the behaviour of sound waves
In air). To verify this assumption, Michelson and Morley made an interfero
meter in 1887. With this the difference in speed of light, in the direction of
the orbit around the Sun and perpendicular thereto, could be measured
very accurately. The outcome of the measurements was very surprising:
the speed of light is always the same in all directions
The conclusion must therefore be, that ether doesn't exists.
All electromagnetic waves, including radio waves, are transmitted constantly
with the speed of light. Many applications are possible because the speed of
light is constant, such as:
|~ Einstein's theory of relativity |
|~ the modern astronomy |
|~ GPS (= global positioning system) |
The energy density of sunlight
|~ at the height of the Earth's surface, when the sky is completely |
|cloudless and at perpendicular radiation the power of sunlight |
|is 1 kilowatt per square meter |
|~ in 1 hour an amount of energy of 1 kilowatt-hour per square |
|meter is irradiated |
|~ the speed of light is 300.000 kilometres per second |
|~ during 1 hour light travels over a distance of |
|3600 × 300.000 kilometres = 1012 metres |
|~ so the energy density of sunlight is 1 kilowatt-hour per |
|1012 cubic metres (1012 cubic metres is the equivalent |
|of a cube with an edge of 10 kilometres) |
Solar energy in the Sahara
Near the Equator the day length is 12 hours throughout the year. The
Integrated amount of solar energy, irradiated on a horizontally placed
solar panel, at a completely cloudless sky, can be calculated easily.
Compared to 1 hour of the Sun perpendicularly above the panel, this
is 8 times more. (for example:2 hours after sunrise and 2 hours before
sunset, the Sun is 30 degrees above the horizon, then the amount of
beaming energy will be half of the maximum)
So the production factor during a year will be 33,3% In the Netherlands
this is 11,4%. So in the Sahara the production factor is only 3 times
as much as in the Netherlands. At the application of "concentrated
solar power" (CSP). the production factor will be more, as a result of
the use of a sun tracking system This results in a production factor
of approximately 45%. A problem consists of the pollution of the solar
collectors, through the frequent occurrence of sand storms. Fantasies
of "solar fields" with huge amounts of solar energy in the Sahara,
therefore need to be seen in perspective
Solar radiation in the Netherlands in 1999
(Statistical Yearbook 2001, kilojoules per square centimetre per year)
|Dec Jan Feb |Mar Apr May |June July Aug |Sept Oct Nov |
|26 |119 |159 |58 |
|~ total: 26 + 119 + 159 + 58 = 362 kilojoules per |
|square centimetre per year |
|~ that equals 3.620.000 kilojoules per square metre per year |
|~ 1 kilowatt-hour = 3600 kilojoules |
|~ the amount of radiant energy per square meter therefore |
|was 1006 kilowatt-hours per year |
In this overview our starting point is 1000 kilowatt-hours per square
metre per year. That are 2,7 kilowatt-hours per day
The Leopoldhove
The Leopoldhove in Zoetermeer, is a healthcare facility with associated
properties. On the roofs of the complex is a large number of solar panels.
In the hall of the main building, one can read the energy yield of those
panels on a display
Some data of the Leopoldhove
|~ 606 panels with a total area of 770 square meters |
|~ the annual yield is 64.000 kilowatt-hours (18 households) |
|~ the annual yield per square metre is 83 kilowatt-hours |
|~ the average daily yield is 175 kilowatt-hours |
Overview of the monthly energy yield of the Leopoldhove (2010)
| |kilowatt-hours |percentage |
| January | 1040 | 1,6 |
| February | 1582 | 2,5 |
| March | 5244 | 8,2 |
| April | 8454 | 13,3 |
| May |11216 | 17,6 |
| June |10301 | 16,2 |
| July | 9544 | 14,9 |
| August | 6801 | 10,7 |
| September | 4933 | 7,7 |
| October | 3357 | 5,3 |
| November | 959 | 1,5 |
| December | 348 | 0,5 |
| total |63779 |100,0 |
|~ In May the energy yield was 32 times more than in December |
|~ In the months May, June and July the yield was 13 times more |
|than in November, December and January. |
Comparison of the daily yield of the "Leopoldhove" when heaven is cloudy or cloudless (2010)
|cloudy |cloudless |
|11 June 63 kilowatt-hours | 3 June 520 kilowatt-hours |
|27 November 3 kilowatt-hours |16 November 101 kilowatt-hours |
From 16 to 29 December the total yield was 0 kilowatt-hour, due to snow
on the solar panels
Energy yield of the "Leopoldhove" (kilowatt-hours per day in 2010)
[pic]
Energy yield of the "Leopoldhove" (kilowatt-hours per week in 2010)
[pic]
Daylight in the Netherlands (hours per day, from sunrise until sunset)
[pic]
Daylight in the Netherlands (spring, summer, autumn and winter)
|[pic] |[pic] |[pic] |[pic] |
|20 March |21 June |22 September |21 December |
|H = 37,8 degrees |H = 61,4 degrees |H = 38,2 degrees |H = 14,5 degrees |
|D = 12 hours 11 min. |D = 16 hours 45 min. |D = 12 hours 11 min. |D = 07 hours 44 min. |
H = the highest altitude of the Sun, in the middle of the day
D = the day length, measured from sunrise to sunset
Wind energy
Everyone is in favour of wind energy, until a windmill will be placed in the
neighbourhood. NIMBY One experiences or expects the following problems:
|~ noise |
|~ at a particular position of the Sun the rotating blades can interrupt |
|the sunlight in an annoying way (a few hours per year) |
|~ the rotating blades may sometimes cause interference with radio |
|transmissions, in the reception of terrestrial television stations and |
|(ships)radar |
|~ horizon pollution |
|(endless residential areas on the horizon are no problem) |
|~ birds getting killed against the blades |
|~ wind farms at sea will cause degradation of flora and fauna on |
|the seabed (?) |
|~ large wind farms in sea (for example 1.000 windmills) will cause less |
|rain and wind, while also the height of the waves will be reduced. |
Comparison of Solar and Wind energy
solar energy Waldpolenz Solar Park (page 17)
|~ 550.000 solar panels of 85 watts peak |
|~ the total power is 40 megawatts |
|~ the production factor is 11,4% |
|~ the total land area is 1 square kilometre |
|~ the annual energy yield will be 40.000 megawatt-hours |
|~ that amounts to 40.000 megawatt-hours per square |
|kilometre per year |
wind energy IJmuiden wind farm (page 10)
|~ 60 wind turbines of 2 megawatts |
|~ the total power is 120 megawatts |
|~ the production factor (at sea) is 40% |
|~ the total sea area is 14 square kilometres |
|~ the annual energy yield will be 422.000 megawatt-hours |
|~ that amounts to 30.000 megawatt-hours per square |
|kilometre per year |
Some of the features of solar energy
|~ in winter the yield of solar energy will be little and |
|during the night it will be zero while than the need |
|for energy is large |
|~ solar energy can not be realized at sea |
|~ the used land area is not available for other purposes |
|~ fixed solar panels require low maintenance |
Some of the features of wind energy
|~ in winter the yield of wind energy will be relatively high |
|while than the need for energy is also high |
|~ at wind energy on land the area can be used for |
|agriculture or cows can graze there |
|~ also solar panels could be placed there |
|~ wind mills require a lot of maintenance |
Some fuels and CO2
Some fuels: oxygen consumption and combustion products (kilograms)
|fuel |oxygen |carbon dioxide |water |
| 1 kilogram of carbon |2,67 |3,67 |- - - |
| 1 kilogram of methane |4,00 |2,75 |2,25 |
| 1 kilogram of petrol |3,51 |3,09 |1,42 |
| 1 kilogram of diesel oil |3,47 |3,12 |1,35 |
| 1 kilogram of hydrogen |8,00 |- - - |9,00 |
|~ the mass of fuel + oxygen = the mass of carbon dioxide + water |
|(law of conservation of mass) |
|~ in burning carbon only carbon dioxide will come into being (CO2) |
|~ in burning hydrocarbons (methane, petrol and diesel oil) |
|carbon dioxide + water will come into being |
|~ in burning hydrogen only water will come into being |
CO2 emissions per kilowatt-hour primary energy, from the incineration of
single fuels
|fuel |kilograms CO2 |energy-content |kilograms CO2 |
| |(carbon dioxide) |(kilowatt-hours) |per kilowatt-hour |
| 1 kilogram of coal |2,6 | 8,1 |0,32 |
| 1 cubic metre of natural gas |1,8 | 8,8 |0,20 |
| 1 litre of petrol |2,4 | 9,1 |0,26 |
| 1 litre of diesel oil |2,7 |10,0 |0,27 |
|~ coal contains 80% of carbon |
|~ the mass of 1 cubic metre of natural gas is |
|0,83 kilograms and it contains 82% of methane |
|~ the mass of 1 litre of petrol is 0,70 kilograms |
|~ the mass of 1 litre of diesel oil is 0,84 kilograms |
CO2-emissions per kilowatt-hour primary energy, from the incineration
of single fuels according to the "well-to-wheel" method
|fuel |kilograms CO2 |energy-content |kilograms CO2 |
| |(carbon dioxide) |(kilowatt-hours) |per kilowatt-hour |
| 1 kilogram of coal |3,1 | 8,1 |0,38 |
| 1 cubic metre of natural gas |2,2 | 8,8 |0,25 |
| 1 litre of petrol |3,1 | 9,1 |0,34 |
| 1 litre of diesel oil |3,5 |10,0 |0,35 |
|~ Through burning of petrol or diesel oil, CO2 emissions per kilowatt-hour |
|primary energy are almost as much as those of the burning of coal |
|(coal-fired power plants "are not permitted", but the car "is a must") |
CO2 emissions caused by cars in the Netherlands
|~ in 2008 the amount of cars in the Netherlands was 7 million pieces. |
|~ on average 1.444 litres of petrol was consumed per car per year |
|~ so 7 million cars consumed 10 billion litres of petrol |
|~ 24 billion kilograms of CO2 was produced in burning the petrol. |
CO2 emissions caused by domestic electricity consumption
in the Netherlands
|~ the annual electricity consumption of all households in the |
|Netherlands Is 62 billion kilowatt-hours primary energy |
|~ from only coal-fired power plants |
|20 billion kilograms of CO2 would arise |
|~ from only gas-fired power plants |
|12 billion kilograms of CO2 would arise |
In the Netherlands electricity is generated from both coal-fired and gas-fired power
plants. So passenger car traffic causes more CO2 emissions than the electricity
production for all households. So even if one would only apply coal-fired power
plants. It is amazing that environmentalists protest against coal-fired power
plants, while they are using cars like anyone else.
("environmental pastors")
CO2 emissions "well-to-plug" of electricity, generated in a gas-fired
power plant
|~ during combustion of 1 cubic meter of natural gas 2,2 kilograms |
|of CO2 arises (CO2 emissions in the production and distribution |
|of natural gas included) |
|~ the energy content of 1 cubic meter of natural gas |
|= 8,8 kilowatt-hours |
|~ the total efficiency of electricity generation is 33% |
|~ so the energy from the outlet is 0,33 × 8,8 = 2,9 kilowatt-hours |
|per cubic meter of natural gas |
|~ 1 kilowatt-hour from the outlet causes: "well-to-plug" |
|2,2 / 2,9 = 0,760 kilograms = 760 grams CO2 |
|(so 4 kilowatt-hours causes almost 3,1 kilograms CO2, see below) |
Comparison petrol - electricity at the same CO2 emission
|energy |CO2-emissions |efficiency |useful labour |
| 1 litre of petrol |3,1 kilograms |petrol engine |2,3 kilowatt-hours |
|9,1 kilowatt-hours |"well-to-pump |= 25% | |
| electricity |3,1 kilograms |electric motor |3,6 kilowatt-hours |
|4 kilowatt-hours |"well-to-plug |= 90% | |
At a gas-fired power plant and at the same CO2 emissions an electric motor will
deliver 1,6 times as much useful labour as a petrol engine.
At a coal-fired power plant virtually there will be no difference.
The greenhouse effect
Many people think that the greenhouse effect is being caused by the energy which
is being released in the combustion of fossil fuels. That is not the case, because that
amount of energy is negligible compared to the amount of energy of the Sun
beaming on the Earth. The Sun radiates 8000 times more energy per time unit on
Earth, than is generated by human activities. The greenhouse effect is caused by the
carbon dioxide (CO2), that is released in the burning of fossil fuels and above all by
the vapour in the atmosphere. These greenhouse gases let by solar energy towards
the Earth virtually unhindered, while the radiation of heat from the Earth is largely
stopped. As more greenhouse gases are present in the atmosphere Earth cools
down less. However it is questionable whether the effect of carbon dioxide (CO2)
in this process will be as large as has been assumed up to now. That point has not
been settled yet. Maybe the "greenhouse effect" should be categorized the same as
"acid rain" and "the hole in the ozone layer". The future will tell. It is clear however
that the climate is changing in recent years. Think of the melting of the ice at the
North Pole and the disappearance of the "eternal" snow in the Alps. For the past
few years (in Europe) winters have been remarkably warm.
The effective height of the atmosphere
|~ the density of air is 1,29 kilograms per cubic metre |
|at a pressure of 1 atmosphere. |
|~ 1 atmosphere = 1 kilogram per square centimetre |
|= 10.000 kilograms per square metre. |
|~ so the effective height of the atmosphere is |
|10.000 / 1,29 = 8000 meters |
|~ the air pressure decreases with height |
|(decreases less quickly as the height increases). |
|~ at an altitude of 5500 metres the pressure is |
|0,5 atmosphere. |
|~ at 10,5 kilometres height, where most air traffic is |
|taking place, the pressure is still 0,25 atmosphere |
At sea level a height difference of 1 meter is a pressure change
of 1 / 8000 atmosphere = 1 / 8 grams per square centimetre.
Such a difference in elevation is easily measurable with a digital
altimeter.
Light sources
Comparison of various light sources
| |watt |lumen | lumen per watt | light efficiency |
|incandescent lamp |75 | 930 |12 |5% |
|LED-lamp | 7 | 400 |57 |25% |
|energy saving lamp |23 |1550 |67 |29% |
|fluorescent tube |51 |4800 |94 |41% |
|~ the luminous flux of a light source is measured in lumen |
|~ the amount of lumen per watt is a measure of the light output of a |
|light source and may be used for the calculating of the light efficiency |
|~ at 228 lumen per watt, the light efficiency will be 100% |
|(taking into account the luminosity curve of the human eye) |
|~ so the light efficiency of a light source equals: |
|(actual lumen per watt / 228 lumen per watt) × 100% |
Some considerations about LED-lamps
|~ A LED-lamp usually beams bundled light. The efficiency seems more |
|than it is. So it can not be compared directly to a "sphere beamer" |
|such as an energy-saving lamp. |
|~ In addition, the efficiency is adversely affected by the conversion of |
|the mains voltage to the low tension to fire the LED's. |
|(usually 2 to 5 volts) and by the bad labour factor. |
|~ It will take a while, before the LED-lamp can beat the fluorescent |
|lamp, with regard to the light efficiency. It may even be doubted |
|whether that will ever be possible. (for white light). |
|~ The benefits of the LED-lamp are its dimensions, its resilience and |
|longevity. In addition, light is at full strength immediately after |
|switching it on. (much faster than an incandescent lamp). |
|~ For space lighting LED lamps still seem totally unsuitable. They are |
|suitable for street lighting, decor lighting, special lighting effects, back- |
|lighting LCD-screens and applications where coloured light is desired |
|~ In comparison to small light bulbs, such as in flashlights and in rear |
|light of a bicycle, the light efficiency of LED's is very high. |
LED-lamps
The latest LED-lamp by Philips is the 7 watt Master LED type A55. The
packaging indicates that the amount of radiated down light is as much as a 40 watt
incandescent lamp when the lamp is positioned in an armature. Much less light is
radiated to the sides and almost nothing upward. This is in contrast to an ordinary
savings lamp. Half of this LED-lamp consists of a heat sink. This turns out to be so
hot, that one cannot grasp it for long. Therefore it seems highly unlikely, that the
lamp should only absorb 7 watts from the mains. Using this lamp for 3 hours per
day. will save approximately € 7 per year
In the application of LED's as backlight for LCD screens, it is being used that
LED's can be switched without a moment of inertia. The backlight therefore can be
modulated with the image content. A very high contrast ratio of the image can thus
be achieved. In addition, the energy consumption will be low, because the LED's
are burning at full strength only partially. This is in contrast to backlight with
fluorescent tubes. In addition, monitors with LED-backlight can be much thinner.
In the latest Philips LED-TV backlight is provided by more than 1000 LED's
Energy saving lamps
The lifetime of energy saving lamps is rather disappointing, especially when they
are being switched on or off frequently. Often they last not even 1 year. This is in
contrast to ordinary incandescent lamps that last much longer. An energy saving
lamp cannot be switched more then 2500 times. At a burning time of 3 minutes (for
example, on the toilet) the lifetime is 125 hours. At a burning time of 4 hours per
period the lifetime is 10.000 hours. The best choice depends on the application.
Between 2009 and 2012 the incandescent lamp will gradually be withdrawn from
the market. This will reduce the CO2 problem a (very small) part. The energy
consumption of lighting is only 4% of total energy consumption. This measure will
contribute little, but might make people more conscious of the environment. Both
energy saving lamps and fluorescent lamps contain harmful substances (e.g.
mercury) and must therefore be considered as small chemical waste
OLED's
Philips, has begun to develop lighting through "OLED's" (organic LED's). These
are not lighting lamps, but light radiant panels, similar to an LCD screen. The
expectation is that some day a light output of 140 lumen per watt can be realized.
That corresponds to a light efficiency of approximately 60%.
Aircraft
| |number of |blank |fuel |max. |flight range |km / litre / |
| |passengers |weight |weight |take-off |kilometres |passenger |
| Boeing 747 |524 |181 tonnes |173 tonnes |396 tonnes |13,445 |32.5 |
| Airbus 380 |840 |275 tonnes |261 tonnes |540 tonnes |14,450 |37.2 |
the density of kerosene = 0,8 kilogram / cubic decimetre
An airplane with a jet engine
Some people think that a jet engine (or a rocket engine) "repels" itself against the air.
That is not the case and a rocket engine (which carries its own oxygen) even works
in vacuum.
|~ the action of a jet engine (and the rocket engine), is based |
|on the principle: action = reaction (Newton’s 3rd Law) |
|~ in the jet engine kerosene is burned with oxygen from air. |
|~ the thrust is caused by the masses of the combustion |
|products + the air through the "bypass" which are emitted |
|at high speed by the jet engine. |
|~ in the jet engine of a Jumbo, a turbofan, the amount of air |
|flowing through the "bypass" along the combustion chamber |
|is 5 times as much as needed for the combustion of the fuel |
|~ the outflow velocity of the combustion products + the air |
|is 285 meters per second. |
In the following calculation example it will be assumed that the density of CO2,
vapour, nitrogen and air are equal. In addition, the effect of the suction of air
through the inlet of the jet engine and the speed compared to the ambient air
will not be considered.
Calculation example of a Jumbo taking off of the runway
|~ a Jumbo with a mass of 300.000 kilograms accelerates on the runway |
|in 55 seconds to the "take off" speed of 290 kilometres per hour |
|~ so: m = 300.000 kilograms t = 55 seconds v = 80 metres per second |
|~ therefore the acceleration a will be 1,5 meters / second2 (v = at) |
|~ the distance travelled S will be ½ × 1,5 × 552 = 2270 meters |
|(S = ½ at2) |
|~ the kinetic energy E will be ½ × 300.000 × 802 = 960.000.000 joules |
|= 960.000 kilojoules = 267 kilowatt-hours (E = ½ mv2) |
The jet engine
|~ 3,47 kilograms of oxygen will be required for the combustion |
|of 1 kilogram of kerosene and consequently 17,35 kilograms |
|of air. (air exists of 20% oxygen and 80% nitrogen) |
|~ the mass of 1 kilogram of kerosene must be added, this |
|amounts to 18,35 kilograms |
|~ the amount of air flowing along the combustion chamber will |
|be 5 × 17,35 = 86,75 kilograms |
|~ the total emission adds up to 105 kilograms per second |
|during the combustion of 1 kilogram of kerosene per second |
|~ at an outflow velocity of 285 metres per second, the thrust |
|will be: 285 × 105 = 30.000 kilogram-meters per second2 |
|= 30.000 newtons |
|~ for the acceleration of 1,5 meter / second2 of a jumbo of |
|300.000 kilograms, 450.000 newtons are required. |
|~ this will take a total of 450.000 / 30.000 = 15 kilograms |
|of kerosene per second |
Fuel consumption at cruising speed and during take off
|~ fuel consumption of a Jumbo at a cruising speed of |
|900 kilometres per hour will be 15 litres of kerosene |
|per kilometre (15 litres = 12 kilograms) |
|~ 900 kilometres per hour = 1 kilometre in 4 seconds |
|~ therefore the fuel consumption at cruising speed will be |
|12 kilograms in 4 seconds |
|~ during take off the fuel consumption is 15 kilograms in 1 second |
|~ per second that will be 5 times as much as at cruising speed. |
Electric train
|~ The basic implementation of the Double Decker consists of 4 wagons |
|~ The gross power is 1890 kilowatts, at an efficiency of 85%. |
|~ Nowadays the voltage on the overhead contact line is 1800 volts. |
|~ At full power this train will consume more than 1000 amperes and |
|will represent an electrical resistance of about 2 ohms. |
|~ The direct current, submitted by a power station is fed to the train |
|through the overhead line, while the rails are the return circuit. |
|~ The total resistance of 10 kilometres of overhead line + rails is |
|about 0,2 ohms. |
|~ The distance between 2 power stations is up to 20 kilometres. |
|Therefore the distance between the train and the power station is |
|never more than 10 kilometres. |
During the last few years more power stations have been built on busy tracks.
Therefore the average distance between the train and a power station has been
decreased. The total copper cross-section of the overhead contact line on a
double track is 10 square centimetres. This is being obtained by switching in
parallel all 8 wires above the rails
(per rail: 1 reinforcing cable, 1 carrying cable and 2 overhead contact wires)
The energy losses in the overhead line of a train
|~ Electric trains are driving at 1800 volt direct current in |
|the Netherlands. (rated 1500 volts). |
|~ The energy consumption of a train = voltage × current × time. |
|~ For example: a 5 times higher voltage will result in a current |
|that is 5 times smaller (at the same energy consumption), |
|~ The energy losses in the overhead line are proportional to |
|the square of the current. |
|~ So the energy losses will be 25 times smaller. |
Nevertheless, it seems unlikely for the Dutch Railways to apply a higher
supply voltage at any time. Only on the tracks of the "Betuwe line" and
the "High Speed Line" 25 kilovolts alternating current has been applied.
Cycling
Power and energy when cycling on a flat road, sitting upright and
without wind
A = the power necessary for overcoming the mechanical resistance
B = the power necessary for overcoming the air resistance
C = the total required power
D = the energy per kilometre
|speed |A |B |C |D |
|10 km / hour |8 watts | 7 watts | 15 watts | 1,5 watt-hours |
|20 km / hour |18 watts | 56 watts | 74 watts | 3,7 watt-hours |
|30 km / hour |32 watts |189 watts |221 watts | 7,4 watt-hours |
|40 km / hour |52 watts |448 watts |500 watts |12,5 watt-hours |
|~ A well-trained cyclist can provide a continuous power of 130 watts |
|When there is no wind a speed of 25 kilometres per hour will be |
|reached on a touring bicycle. |
|~ At a recumbent and the same power one reaches 32 kilometres |
|per hour. |
|~ A professional racer can deliver 300 watts continuously. On a race |
|bike that will be sufficient for a speed of 40 kilometres per hour. |
|~ Lance Armstrong ever reached 450 watts Thus he was able to |
|mount the "Alpe d'Huez" in 38 minutes. The height difference |
|is 1061 metres and the distance is 13,8 kilometres. |
|So the average speed was 21,8 kilometres per hour. |
Power needed for overcoming the air resistance is proportional to the
3rd power of the speed of a vehicle. (see column B of the table above)
|~ the air resistance of a vehicle is proportional |
|to the 2nd power of its speed. |
|~ power = air resistance × speed |
Energy used for overcoming the air resistance during the same time
is proportional to the 3rd power of the speed of a vehicle.
|~ energy = power × time |
For example:
When one is cycling a distance of 30 kilometres in 1 hour, than it costs
1,53 = 3,38 times as much energy (effort) to overcome the air resistance,
compared to cycling a distance of 20 kilometres in 1 hour.
(think in this context to win a cycling race, or improving the World hour
record on the bicycle)
Energy used for overcoming the air resistance on the same distance
is proportional to the 2nd power of the speed of a vehicle
|~ the air resistance of a vehicle is proportional |
|to the 2nd power of the speed. |
|~ energy = air resistance × distance travelled |
For example:
A car driving at a speed of 120 kilometres per hour, uses 1,52 = 2,25 times
more energy, then a car driving at a speed of 80 kilometres per hour over
the same distance
Wind during cycling is always detrimental if one returns to the place
of departure
calculation example:
|~ suppose a distance of 30 kilometres there and back. |
|~ no wind, a cycling speed of 20 kilometres per hour |
|then the cyclist will be cycling for 3 hours. |
|~ backwind or headwind of 10 kilometres per hour |
|the cyclist experiences the same air resistance when the speed |
|relative to the wind is the same. With backwind the cycling speed |
|will be 30 kilometres per hour and with headwind 10 kilometres |
|per hour. Now the cyclist will be cycling 1+ 3 = 4 hours |
|So the amount of supplied energy will be 4 / 3 = 1,33 times as |
|much as when there is no wind. |
Also when there is crosswind a cyclist has to deliver more energy
than when there is no wind
Source: the book "Hoor je beter in het donker?" ("Do you hear
better in the dark?") author: Jo Hermans, professor at Leiden University
calculation example:
|~ suppose the crosswind is just as strong as the headwind |
|~ than the airspeed of the resultant of the crosswind and the headwind |
|is √2 times as large as the air speed in the cycling direction |
|~ the resultant makes an angle of 45 degrees with the cycling direction |
|~ the air resistance is proportional to the 2nd power of the air speed |
|~ therefore the air resistance of the resultant is 2 times larger than the |
|air resistance when there is no wind in the cycling direction |
|~ the resultant can be dissolved in the air resistance in the cycling |
|direction and perpendicular to the cycling direction |
|~ the result is that due to the crosswind, the air resistance in the |
|cycling direction is √ 2 = 1,41 times greater than at no wind. |
|~ so (in this example) it costs 1,41 times more energy to cycle |
|the same distance than at no crosswind |
Comparison between a ramp and a headwind at the same bicycle
power (at a speed of 20 kilometres per hour)
|a slope |or headwind |bicycle power |
|0% | 0,0 km / hour | 75 watts |
|1% | 7,9 km / hour |129 watts |
|2% |13,7 km / hour |184 watts |
|3% |19,1 km / hour |238 watts |
|4% |23,4 km / hour |292 watts |
|5% |27,4 km / hour |346 watts |
|6% |31,3 km / hour |400 watts |
Electric bicycles
|~ an upright seated cyclist must deliver a power of 180 watts at |
|a speed of 20 kilometres per hour and a headwind of 4 meters |
|per second (wind force 3). |
|~ that corresponds with an amount of energy of 9 watt-hours |
|per kilometre |
|~ therefore 4,5 watt-hours of mechanical energy per kilometre |
|is needed for 50% support by an electric bicycle. |
|~ the efficiency of the electric motor with associated energy |
|control is 90% |
|~ therefore at 50% support the battery of an electric bicycle has |
|to deliver approximately 4,5 / 0,9 = 5 watt-hours per kilometre. |
That is a minimum value, because one uses the support especially at (strong)
headwind. The (average) action radius of an electric bicycle at 50% support
is easy to calculate.
| action radius (kilometres) = |
|energy-content of the battery (watt-hours) / 5 (watt-hours per kilometre) |
An example shows, that this is correct. The Trek LM500 has a battery with
an energy content of 400 watt-hours. Therefore the action radius should be
400 / 5 = 80 kilometres. This corresponds to the data of Bosch.
As long as one cycles on a flat road with a constant speed, the weight of the
bicycle will have hardly any affect on the action radius. (Newton’s 1st Law)
There are 3 implementing forms of electric bicycles:
|~ drive by means of an electric motor in the front wheel |
|~ drive by means of an electric motor attached to the |
|bottom bracket |
|~ drive by means of an electric motor in the rear wheel |
Some examples:
The Antec Vela
|~ a lithium-ion battery (removable) |
|36 volt at 10,5 ampere-hours |
|~ so the energy content is 378 watt-hours |
|~ the support can be adjusted continuously between |
|10% and 90% |
|~ equipped with a 7-speed hub gear |
|~ the motor is in the front wheel |
|~ at 50% support the action radius will be 60 kilometres. |
The Trek LM500
|~ a lithium-ion battery (removable) |
|36 volt at 11 ampere-hours |
|~ so the energy content is 400 watt-hours |
|~ equipped with an 8-speed hub gear |
|~ supplied with the Bosch middle motor |
|~ the motor is attached to the bottom bracket |
|~ at 50% support the action radius will be 80 kilometres |
The advantage of this construction is that one can easily remove the wheels,
when replacing a tire. In addition, any desired type of gear assembly and a
dense chain cabinet can be applied. It is strange that nevertheless this bike
still has an open chain.
The Sparta Ion M-Gear
|~ a nickel metal-hydride battery (not removable) |
|24 volt at 10 ampere-hours. |
|~ so the energy content is 240 watt-hours. |
|~ the motor is in the rear wheel with an integrated |
|pedal sensor |
|~ equipped with a derailleur with 7 gears. |
|~ at 50% support the action radius will be 40 kilometres |
Striking is the very clear and precise indication of the current energy stock
in the battery (in increments of 3%) This allows a good planning of the
support on a long bicycle tour.
Bosch middle motor
Some characteristics of bikes with the Bosch middle motor:
|~ the motor is positioned at the bottom bracket and thus |
|the bike has a low centre of gravity and a good handling |
|~ the power of the cyclist + the motor is transferred via |
|the chain on the rear wheel |
|~ the chain therefore has a hard time compared to other |
|electric bicycles |
|~ the specifications of the Bosch middle motor seem |
|overly optimistic, but are amply achieved in practice |
|(tested on 6000 kilometres) |
|~ the "Intuvia" system has a clear display |
|~ at the handle there is a big + and – button, with which |
|the degree of support can be selected |
|~ this is the first system that one can operate well |
|wearing (thick) gloves |
|~ for each selected support the display shows the |
|corresponding actual, dynamic range |
|~ on the display there is an indication of the instantaneous |
|energy consumption (the power) |
|~ inserting and taking out the battery is very easy, thanks |
|to the built-in handle |
|~ the self-discharge of the battery is only 2% per month |
The Bosch middle motor is a breakthrough in the drive technology
for electric bicycles. Outstanding features are:
|~ the user-friendliness |
|~ the powerful support |
|~ the large action radius |
Bosch middle motor with a 400 watt-hours battery
(moderate wind and 20 kilometres per hour)
|support |watt-hours |action radius |
| |per kilometre | |
|turbo |8,0 | 50 km |
|sport |6,7 | 60 km |
|tour |5,0 | 80 km |
|eco |3,0 |135 km |
Pedal sensor or rotation sensor?
Recently more and more electric bicycles have been launched equipped
with a rotation sensor instead of a pedal sensor. Advantages are the
lower price and the simple construction, The smaller action radius and the
insecurity however are a disadvantage. The application of a rotation sensor,
enables immediately support once the pedals are rotating. Also when little
force is pursued, the motor will be enabled and then delivers virtually all
the energy needed for the propulsion. If one wants to cycle faster, one
must pedal disproportionately more, because than the cyclist himself has
to deliver the extra energy needed. In practice one usually cycles with the speed of the maximum support. A great solution for people who do not
want to work, but this is at the expense of the action radius. If one stops
pedalling, the support usually still goes on for a while. Therefore, these
bikes are often equipped with a switch at the brake handle. If one brakes,
the circuit to the motor is switched off immediately. Electric bicycles with
a rotation sensor are potentially dangerous in traffic, especially for older
cyclists. But one get used to anything. At electric bikes with a pedal
sensor, said problems are entirely absent
Does it take more exercise to cycle an electric bicycle without
support than a regular bicycle?
It is a widespread misunderstanding, that if support is disabled it will be
(a lot) more work on an electric bicycle than on a regular bicycle. Only the
rolling resistance of an electric bicycle is a bit more compared to a regular bicycle, due to more weight of the bicycle. The air resistance will be the
same of course. On a flat road with constant speed the mass (weight) of
the bicycle + rider is not an issue. (Newton’s 1st Law).
The rolling resistance is negligible compared to the air resistance, especially
with moderate or strong headwind. Of course the larger weight will play an
important role during acceleration and at a slope. But during a long bicycle
ride slopes will not be present very often. (in the Netherlands)
For example: (at a speed of 20 kilometres per hour)
A = a bicycle of 15 kilograms, a cyclist of 75 kilograms, no wind
B = a bicycle of 25 kilograms, a cyclist of 75 kilograms, no wind
C = a bicycle of 25 kilograms, a cyclist of 75 kilograms, head wind 4 metres per second
| |A |B |C |
|rolling resistance | 2,6 newton | 2,9 newton | 2,9 newton |
|air resistance | 9,6 newton | 9,6 newton |28,5 newton |
|mechanical resistance | 0,6 newton | 0,6 newton | 1,6 newton |
|total cycling resistance |12,8 newton |13,1 newton |33,0 newton |
|total labour per kilometre |3,55 watt-hours |3,64 watt-hours |9,17 watt-hours |
The action radius of an electric bicycle is largely determined
by the air resistance
Recently I got talking to a couple with an electric bicycle. The man with a
large stature said that he realized a much smaller range on his bicycle
than his frail wife. He thought that this was caused by the difference in
weight. That is not the case, because at a constant speed the weight
plays no role. (apart from a negligible difference in rolling friction). The difference in the action radius is caused by the difference in air resistance.
The air resistance is proportional to the frontal area of the cyclist + bicycle.
If the frontal area becomes 50% larger the action radius will decrease
with 25%. One can calculate this easily by means of the data in column B
in the table above
The benefits of an electric bicycle are:
| 1. the energy consumption of an electric bicycle is |
|10 times less than that of a moped |
|2. the support over 80 kilometres costs less than |
|10 euro cents (= 0,5 kilowatt-hour) |
|3. one hour electric cycling consumes (gross) as much |
|electrical energy as it takes to watch TV for one hour. |
|So electric cycling can be called "energy-neutral", |
|because if one does not cycle one is sitting in front |
|of the TV or behind the computer. |
|4. an electric bicycle requires virtually no maintenance |
|(just as much as an ordinary bicycle) |
|5. a helmet is not obligatory on an electric bicycle |
|6. insurance is not compulsory for an electric bicycle |
|7. an electric bicycle is much sportier and healthier |
|than a moped, because one always has to pedal |
|8. an electric bicycle does not smell, makes no noise |
|and does not leak oil |
|9. one can also just cycle on an electric bicycle |
|10. if one owns an electric bicycle one cycles |
|more often, further and faster |
The hydrogen bicycle
The hydrogen bicycle is the latest news in the field of electric bicycles.
This is a bicycle where the battery has been replaced by a fuel cell.
Some global data:
|~ the capacity of the fuel cell is 24 volts at 10 amperes, |
|so 240 watt-hours |
|~ 2 small tanks contain 600 litres of pure hydrogen stored |
|in the form of a chemical compound (metal hydride) |
|~ the consumption at maximum power is 3 litres of |
|hydrogen per minute, at a pressure of 0,4 bar. |
|~ at o degrees Celsius it takes 30 minutes to fill the tanks |
|~ the temperature of the tanks must be over 25 degrees |
|Celsius to release the hydrogen from the metal hydride |
|~ the efficiency of the fuel cell is 50% |
|~ the weight of the fuel cell is 0,76 kilogram |
|~ the weight of the 2 hydrogen tanks is 6,5 kilograms |
|~ according to the manufacturer, the system is safe, |
|because it works with low pressures |
|~ the tanks have a high storage density |
|~ the tanks and the fuel cell have a long lifespan |
The fuelling of the hydrogen is cumbersome and the question is, of course,
"where does the hydrogen come from?", especially during a bicycle ride
Nevertheless, this is a first step to a bicycle that runs on hydrogen and as
such an interesting development. It is highly unlikely, that the hydrogen
bicycle ever will be used.
Charging the new generation of lithium-ion batteries in a regular electric
bicycle only takes a few minutes and it can be done virtually anywhere
Moreover, it is much cheaper. (10 euro cents). The combination of a fuel
cell and hydrogen tanks seems to be useful in places where no electricity
supply is available, such as camping sites and recreational ships.
Power plants
Fuel and capacity (power) of some power plants in the Netherlands
|location and name |fuel |power |
| Borssele | | |
|nuclear plant |uranium |449 megawatts |
| Amsterdam | | |
|Hemweg 8 |coal |830 megawatts |
|Hemweg 9 |natural gas |435 megawatts |
| Geertruidenberg | | |
|Amercentrale 8 |coal + |620 megawatts |
|Amercentrale 9 |biomass |620 megawatts |
| Maasbracht | | |
|Clauscentrale 1 |natural gas |640 megawatts |
|Clauscentrale 2 |natural gas |640 megawatts |
| Eemshaven | | |
|5 CHP plants |natural gas |1750 megawatts |
|1 combi plant |natural gas |675 megawatts |
The combined gas and steam plant
|~ in a combined gas and steam plant electricity |
|is generated using 2 turbines. |
|~ the first turbine is a gas turbine. |
|~ the second turbine is a steam turbine. This one |
|is powered by steam, produced by the heat of |
|the exhaust gases of the gas turbine. |
|~ the gas and steam turbine often drive the same |
|axis, so together they drive the same generator. |
|~ the efficiency of a combined gas and steam |
|plant is up to 58% |
Most of the new power plants in Western Europe to be built will
be combined gas and steam plants.
The ratio between the inlet temperature of the gas turbine and the outlet
temperature of the steam turbine in a combined gas and steam plant is
much larger than that of a single process. The total efficiency is therefore
larger. (Carnot). The gas turbine offers an efficiency of 40%. From the
exhaust gases, which still contain 60% of the energy, 30% is won via the
steam turbine. That delivers 18% extra. This amounts to a total efficiency
of 58%.
The nuclear power plant in Borssele
The nuclear power plant in Borssele has a capacity of 449 megawatts.
In the year 2000 the energy yield was 3,7 billion kilowatt-hours.
The production factor of this power plant was 94%. A nuclear power
plant is poorly regulated and therefore it almost always works at
maximum power. The Dutch Government has decided, that the nuclear
power plant can remain in operation until 2033
The largest nuclear power plant in the world
This power plant is located in Japan, on the west coast, in Kashiwazaki,
Niigata. It consists of 7 units with a combined capacity of 8212 megawatts,
which is 18 times more than the nuclear power plant in Borssele and
7 times more than a large conventional power plant in the Netherlands.
In 2008 the electricity consumption in the Netherlands was 109 billion
kilowatt-hours
This could be excited with (rounded):
| either 10.000 windmills of 3 megawatts (at sea) |no CO2 |
|or 1.000.000.000 solar panels of 1 square meter |no CO2 |
|or 47.000.000 tonnes of wood (or biomass) |CO2 neutral |
|or 31.000.000 tonnes of coal |81.000.000 tonnes of CO2 |
|or 29.000.000 cubic meters of natural gas |52.000.000 tonnes of CO2 |
|or 250 tonnes of enriched uranium |no CO2 |
For the same amount of electricity, produced in a coal-fired power plant 1,56 times
as much carbon dioxide (CO2) is released as in a gas-fired power plant
Electric cars
|~ in 2005 there were 7 million cars in the Netherlands. |
|~ per car on average 17.400 kilometres was driven per year. |
|~ that is a total distance of 120 billion kilometres per year |
|(800 times the distance Earth-Sun). |
|~ on average an electric car consumes 150 watt-hours per kilometre |
If all cars in the Netherlands would drive electrically, then would be needed:
120 × 150 = 18000 billion watt-hours = 18 billion kilowatt-hours per year.
For the generation of this amount of energy 5 more 600 megawatt power
plants would be needed. The electricity consumption of all households in the Netherlands is 25 billion kilowatt-hours per year. So the capacity of the
entire electricity infrastructure (power lines, cables, transformers etc.)
should therefore be increased substantially
Recently more and more articles appear in the press about very fast
rechargeable batteries and super capacitors. Will they be a solution for
the energy supply in electric cars? No, not really.
For example:
|~ the action radius of an electric car is 200 kilometres |
|~ the energy consumption is 150 watt-hours per kilometre |
|~ then the battery should have an energy content of |
|30 kilowatt-hours |
|~ at a charging time of 6 minutes (= 0,1 hours) one arrives |
|at a power of 300 kilowatts |
|~ at a 230 / 400 volt 3 phase network this requires a |
|current of 435 amperes per phase |
That doesn't appear to be a realistic solution.
Press release on 29 December 2008:
"The electric car is not yet ready for a rapid advance. The boss of Bosch,
the largest car-supplier in the world, calls the expectations about electric
cars overly euphoric. Cars with an internal combustion engine will certainly dominate the streetscape another twenty years"
The following abbreviations are used in the tables below:
energy = the energy consumption of the electric motor, in watt-hours
per kilometre, at a speed of 100 kilometres per hour
range = the range in kilometres, at a constant speed
of 100 kilometres per hour
batt = the energy content of the battery in kilowatt-hours
power = the power of the electric motor in kilowatts
accel = the acceleration from 0 - 100 kilometres per hour, in seconds
top = the top speed in kilometres per hour
prim = the primary energy consumption in watt-hours per kilometre
km / l = the kilometres per litre petrol equivalent, at
a speed of 100 kilometres per hour
Comparison of some electric cars and the Prius
| |
A few electric cars that have appeared recently on the market
| |energy |range |batt |power |accel |top |prim |km / l |
| Nissan Leaf |150 |199 - 160 |24,0 | 80 |11,5 |144 |500 |18,2 |
| Citroën C-zero |125 |150 - 128 |16,0 | 49 |15,9 |130 |417 |21,8 |
| Mitsubishi i-MiEV |125 |160 - 128 |16,0 | 49 |15,9 |130 |417 |21,8 |
| Renault Kangoo ZE |155 |170 - 142 |22,0 | 44 |20,3 |130 |517 |17,6 |
| Renault Fluence ZOE |147 |195 - 150 |22,0 | 65 |13,5 |135 |490 |18,6 |
| Renault Fluence Z.E. |176 |185 - 125 |22,0 | 70 |13,0 |135 |587 |15,5 |
| Volkswagen e-up |117 |160 - 160 |18,7 | 60 |12,4 |130 |390 |23,3 |
| BMW i3 |129 |190 - 147 |19,0 |125 | 7,2 |150 |430 |21,2 |
| range (kilometres) = energy content of the battery (watt-hours) |
|/ energy consumption of the electric motor (watt-hours per kilometre) |
The left number in the column range comes from the manufacturer..
The right number is the calculated value. The data of the manufacturer
should be read with a “grain of salt”. The electric car drives,
converted in the petrol equivalent, about 20 km per litre
The problems at the electric car are:
|~ the small range |
|~ the long charging time of the battery |
|~ the high price of the battery |
As long as these problems have not been resolved, there can be no
question of a large scale use of the electric car.
It is significant that Toyota has withdrawn from the market of electric cars
The plug-in hybrid car
In 2012 Toyota launched the plug-in Prius. This plug-in hybrid car has
a relatively large battery that can be charged from the mains. The energy
content of the battery will be sufficient to drive electrically for 20 kilometres.
That is sufficient for commuting (a single trip) or shopping
Some data: (borrowed from the journal "My Toyota", spring 2011)
|~ the action radius will be 20 kilometres when the battery is |
|fully charged |
|~ the energy content of the battery will be 5,2 kilowatt-hours |
|~ the charging time will be 90 minutes on a standard outlet |
|~ petrol consumption will be 2,6 litres per 100 kilometres on |
|average (that equals 38 kilometres per litre) |
|~ the CO2 emission will be 59 grams per kilometre |
When driving electrically the consumption would be: 5200 / 20 = 260 watt-
hours per kilometre. These data raise some questions. There is no reason
to assume, that the plug-in Prius consumes more energy per kilometre
than the regular Prius. (124 watt-hours per kilometre).
Obviously not the full energy content of the battery will be used in electric
drive mode. The battery is always discharged half way to prolong its
lifetime. So effectively the energy content is only 2,5 kilowatt-hours.
(20 kilometres × 124 watt-hours per kilometre)
According to Toyota the car would have a petrol consumption of 2,6 litres
per 100 kilometres. Apparently one thinks electrical driving will be
emission free, but that of course is not true. If one assumes, that
always 20 kilometres are driven electrically and 40 kilometres on petrol,
than the average consumption will be 2,6 litres of petrol per 100 kilometres.
It is suggested that this car will have a very low CO2 emission. If the CO2
emission at the generation of electricity is also taken into account, then it
turns out that the plug-in hybrid car (indirectly) will produce the same
amount of CO2 as a regular hybrid car. This does not alter the fact, that it
might be fun, to put part of the necessary energy into the battery from the
outlet at home. Depending on how the car will be used, perhaps one doesn't
need to tank petrol anymore or in any case less often than in the past
But in the winter this will not work. Then the gasoline engine runs almost
continuously, in order to heat the car
For the Opel Ampera a similar story applies
|~ at fully electric driving the action radius will be 60 kilometres |
|~ the energy content of the battery will be 16 kilowatt-hours |
When driving electrically the consumption would be: 16000 / 60 = 267 watt-
hours per kilometre. Also in this car obviously only part of the full capacity
of the battery is used.
While driving with the "charging engine" the consumption of petrol is 6 litres
per 100 kilometres. At an efficiency of 25% of the "charging engine" the
energy consumption than will be (0.25 × 6 × 9100) / 100 = 136 watt-hours
per kilometre. If one always drives the first 60 kilometres electrically
followed by 40 kilometres on petrol, then the consumption (seemingly) will
be 2,4 litres per 100 kilometres.
With this kind of calculations one can "prove" everything but the fact
remains, that a "plug-in" hybrid car will be not more fuel-efficient then a
regular hybrid car and (indirectly) causes comparable CO2 emissions.
Comparison of an electric car, a hybrid car
and a petrol car
Comparison on the basis of energy consumption, CO2 emissions and the
kilometre price. The data are valid for a constant speed of 100 kilometres
per hour
electric car, the Tesla model S
|~ the electric motor never needs to warm up |
|~ there is no gearbox and so there are no transmission |
|losses |
|~ during braking and speed reduction energy is |
|returned to the battery |
|~ the efficiency of the electric motor is 92% |
|~ with a battery of 85 kilowatt-hours the action |
|radius is 480 kilometres |
|~ so the energy consumption of the electric motor is |
|177 watt-hours per kilometre |
|~ the total efficiency of the car "plug-to-wheel" is 88% |
|~ the electricity consumption from the outlet is |
|177 / 0.88 = 201 watt-hours per kilometre |
|~ the efficiency of electricity generation is 33% |
|~ so the primary energy consumption is |
|201 / 0,33 = 610 watt-hours per kilometre |
|~ 1 kilowatt-hour from the outlet causes 760 grams |
|of CO2 when a gas-fired power plant is applied |
|~ the CO2 emission at 201 watt-hours from the outlet |
|is 0,20 × 760 = 152 grams per kilometre |
|~ 1 kilowatt-hour from the outlet costs 20 euro cents |
|~ so the kilometre price is 4,02 euro cents |
hybrid car, the Toyota Prius
|~ the cold petrol engine must be warmed up first, that takes |
|a lot of energy |
|~ the continuously variable gear works with a very high |
|efficiency |
|~ during braking and speed reduction energy is returned to |
|the battery. |
|~ the Atkinson petrol engine is running under circumstances |
|where the efficiency is high, so with a constant speed and |
|maximum torque |
|~ then the efficiency of this petrol engine is 34% |
|~ the petrol engine is never running idle |
|~ the energy content of 1 litre of petrol is 9100 watt-hours |
|~ petrol consumption is 4 litres per 100 kilometres, that is |
|364 watt-hours per kilometre |
|~ the overall efficiency of the production of petrol is 80% |
|~ the primary energy consumption therefore is |
|364 / 0,80 = 455 watt-hours per kilometre |
|~ 1 litre of petrol causes 3,1 kilograms CO2 "well-to-wheel" |
|~ the CO2-emission "well-to-wheel" is |
|(4 × 3,1) / 100 = 124 grams per kilometre |
|~ 1 litre of petrol costs 165 euro cents |
|~ so the kilometre price is 6,60 euro cents |
petrol car, the Opel Astra
|~ the cold petrol engine first must be warmed up, that takes |
|a lot of energy |
|~ there are relatively large energy losses in the gearbox |
|~ regenerating of energy is not possible |
|~ the efficiency of the petrol engine is heavily dependent on |
|the speed and torque |
|~ the petrol engine often runs at a bad efficiency up to 25% |
|but sometimes 0% at idling |
|~ the energy content of 1 litre of petrol is 9100 watt-hours |
|~ petrol consumption is 5,5 litres per 100 kilometres, that is |
|500 watt-hours per kilometre |
|~ the overall efficiency of the production of petrol is 80% |
|~ so the primary energy consumption is |
|500 / 0,80 = 625 watt-hours per kilometre |
|~ 1 litre of petrol causes 3,1 kilograms CO2 "well-to-wheel" |
|~ the CO2-emission "well-to-wheel" is (5,5 × 3,1) / 100 = |
|171 grams per kilometre |
|~ 1 litre of petrol costs 165 euro cents |
|~ so the kilometre price is 9,08 euro cents |
Summary (everything per kilometre)
| |primary |CO2-emission |kilometre price |
| |energy |"well-to-wheel" | |
|Tesla model S |610 watt-hours |152 grams |4,02 euro cents |
|Toyota Prius |455 watt-hours |124 grams |6,60 euro cents |
|Opel Astra |625 watt-hours |171 grams |9,08 euro cents |
There is no fundamental difference in CO2 emission at a fuel-efficient
petrol-car (Prius) or an electric car. At a petrol-car the conversion of
primary energy to mechanical energy occurs in the car. At an electric
car this occurs in the power plant. In both cases, a comparable amount
of CO2 is released. Large-scale generation of sustainable energy, without
CO2 emissions, will still take a long time, or perhaps it will never come.
Can an electric car drive only on "green" energy?
It is often claimed, that electric cars will drive on "green" energy in the long
term and then no CO2 emissions will be released. The battery of an electric
car is almost always charged by electricity from the mains. When the share
of "green" energy in the generation of electricity increases, then of course
that share will not be used selectively by electric cars. Proponents of
electric cars like it to make believe us this. Only the generation of electricity
becomes a bit "greener".
No more than 15% of the electricity in the Netherlands in 2020 will be
generated without CO2 emissions. The CO2 emissions caused indirectly by
electric cars would then decrease with the same percentage. For example,
from 130 to 110 grams CO2 per kilometre. Moreover one must remember
that the electricity consumption will drastically increase, if anyone goes
driving an electric car. The relative share of the "green" energy will then
be reduced.
Can an electric car drive on the energy produced by (a few) solar panels?
Some people sometimes fantasize about ever driving their electric car on
the energy that comes from their own solar panels.
|~ an electric car consumes about 150 watt-hours per kilometre |
|~ for 60 kilometres per day 9 kilowatt-hours per day are needed |
|~ in the Netherlands a solar panel of 1 square meter generates |
|on average 280 watt-hours per day |
|~ therefore 32 square meters of solar panels are needed |
|~ on the energy generated by 1 solar panel of 1 square meter on |
|average one can drive an electric car 1,87 kilometres per day |
The electric race-car
Toyota currently (2011) is experimenting with an electric race-car.
|~ the total power of the 2 electric motors will be 280 kilowatts |
|~ the car accelerates in 3,9 seconds from 0 to 100 kilometres |
|per hour |
|~ the top speed is 260 kilometres per hour |
|~ the lithium-ceramics battery has an energy content of |
|41,5 kilowatt-hours |
|~ the weight of the battery is 350 kilograms |
|~ the weight of the car is 970 kilograms |
|~ the action radius while racing is 42 kilometres |
|(2 rounds on the Nürburgring) |
In 2014 Formula E races for electric cars will be organized
The Opel Astra (or a similar car)
|~ the power of the engine is 74 kilowatts |
|~ at full power the energy used is 296 kilowatt-hours |
|per hour with an efficiency of 25% |
|~ the tank content is 45 litres of petrol, that equals |
|410 kilowatt-hours |
|~ the car can drive 1,4 hours on top speed of 165 |
|kilometres per hour on this amount of energy |
|~ the action radius will be 231 kilometres and the |
|petrol consumption 1 litre per 5,1 kilometres |
|~ at a speed of 100 kilometres per hour the action |
|radius will be 820 kilometres |
The action radius at a speed of 100 kilometres per hour is approximately
820 / 231 = 3,6 times as large as driving on top speed.
Comparison of the action radius of a car with a diesel engine and
a car with a petrol engine
|~ the energy content of diesel oil is 10 kilowatt-hours per litre |
|~ the energy content of petrol is 9,1 kilowatt-hours per litre |
|~ the efficiency of a diesel engine is 35% |
|~ the efficiency of a petrol engine is 25% |
Therefore per litre of fuel, the action radius of a car with a diesel engine is
1,5 times as large as that of a car with a petrol engine. When talking about
the action radius of a car, one should always mention what kind of engine
(and which fuel) it concerns
Comparison means of transport
A = kilometres per litre petrol-equivalent per passenger
|means of transport | A |
| fuel cell car (1 passenger) | 8 |
| petrol car (1 passenger) | 15 |
| electric car (1 passenger) | 20 |
| hybrid car Prius (1 passenger) | 25 |
| aircraft Jumbo (450 passengers) | 30 |
| electric train Thalys (377 passengers) | 50 |
| walking | 108 |
| electric train Double Decker (372 passengers) | 158 |
| Shell eco-marathon "urban-concept" class | 396 |
| cycling | 540 |
| electric bicycle | 545 |
| recumbent |1235 |
| Shell eco-marathon “prototype” class |3316 |
Comparison power plants
A = power per power plant (megawatts)
B = energy generated per power plant in 1 year (megawatt-hours)
C = required number of power plants in the Netherlands
D = production factor (actual annual yield / theoretical annual yield)
|power plant |A |B |C |D |
| coal or gas-fired power plant |600 |4.200.000 | 24 |80,0% |
| nuclear plant Borssele |449 |3.699.000 | 27 |94,0% |
| tidal power plant La Rance |320 | 540.000 | 186 |19,3% |
| wind farm at sea, near IJmuiden |120 | 435.000 | 238 |41,4% |
| solar trough power plant Andasol | 50 | 170.000 | 588 |38,8% |
| sun-voltaic power plant Waldpolenz | 40 | 40.000 |2500 |11,4% |
The energy consumption in the Netherlands is more than 100 billion kilowatt-hours
per year
The energy yield of a 600 megawatt power plant
|~ the energy yield in 1 year = 600 megawatt × 8760 hours × 80% |
|= 4.200.000 megawatt-hours = 4,2 billion kilowatt-hours. |
|~ n 6 years such a power plant produces an amount of energy, |
|equivalent to 1 kilogram mass |
The Waldpolenz Solar Park is a large Sun-voltaic power plant in Germany
This power plant includes 550.000 solar panels on a surface of 1 square
kilometre. 2500 of these power plants will be needed to fulfil the need for
electricity in the Netherlands.
That amounts to 2500 × 550.000 = 1,375 billion panels on a surface of
2500 square kilometres. A field of 50 at 50 kilometres
Solar-energy, a realistic perspective?
Note, this only concerns generation of electrical energy. The total
consumption of primary energy in the Netherlands is a spacious 900 billion
kilowatt-hours per year. For the generation of 100 billion kilowatt-hours of
electricity at an efficiency of 40% an amount of primary energy of 250 billion
kilowatt-hours will be needed.
Therefore the remaining energy of 650 billion kilowatt-hours should ever be excited "green"
We "conveniently" ignore the problem, that Sun-voltaic plants will not deliver
energy when the sky is cloudy and during the night. In addition, the energy
yield during the winter months is 6 times less than in summer.
The production factor of the above-mentioned power plants
|~ Due to maintenance, failures and variable loads the production |
|factor of a conventional power plant will be 80% |
|~ A nuclear power plant has a production factor of 94% because |
|usually it runs continuously at full load. The unproductive part |
|of 6% will be required for maintenance and exchanging the |
|fuel rods. |
|~ The production factor of a windmill is determined by its location |
|(on land or at sea), the wind force and the number of hours the |
|wind is blowing (forcefully). |
|~ Solar trough plants are only situated in places where the sun is |
|shining all day. That is the case in southern Europe and |
|Northern Africa. The radiant energy is 2 to 3 times higher than |
|in the Netherlands. Energy storage is often being used in |
|addition. At daytime part of the radiant energy is stored in the |
|form of heat. When the Sun doesn't shine, the energy delivery |
|to the grid continues because then the stored heat will be |
|used for the generation of electricity. Therefore the production |
|factor will be increased significantly |
|~ At a Sun-voltaic power plant the production factor is |
|determined by the number of hours of sunshine in a year. So |
|by the weather, the latitude and the seasons. Energy storage |
|is not possible. Large-scale application of solar energy, |
|excited by electric solar panels is hardly conceivable, because |
|the Sun isn't shining at night, while a lot of energy will be |
|needed then. |
Some projects of Wubbo Ockels
The sustainable sailboat
This is a large seaworthy sailing yacht (25 metres long), that provides its
own electrical energy needs. The motive power of the wind is 125 kilowatts
at the maximum speed of 18 kilometres per hour,
Part of this, about 10 kilowatts is "drained" for the generation of electricity.
This is done by means of 2 screws on the bottom of the ship
|~ the energy is stored in a lead-acid battery with a capacity |
|of 350 kilowatt-hours and a weight of 12 tonnes |
|~ per day 240 kilowatt-hours can be charged, which is |
|sufficient for 10 days of energy consumption. |
|~ on average the energy need of the ship is 24 kilowatt-hours |
|per day. The sails are being controlled electrically and there |
|are many electronics on board. In addition a lot of energy is |
|needed for hot water, cooking etc. |
The Super bus
Some data:
|~ the super bus is 15 metres long, 2,6 metres wide and |
|1,6 metres high |
|~ the bus is driven electrically and gets the energy from |
|rechargeable lithium-polymer batteries |
|~ the power of the electric motor is 300 kilowatts |
|~ the action radius is 210 kilometres |
|~ the bus can accommodate 23 passengers |
|~ the maximum speed is 250 kilometres per hour |
|~ the energy consumption is just as much as a regular |
|bus that runs at a speed of 100 kilometres per hour. |
The idea is, that on long stretches the super bus drives on a specially
landscaped roadway, with a speed of about 200 kilometres per hour.
The bus may also drive on an ordinary road and put the passengers
down in front of their doors. The construction of the special roadway
is much cheaper than the construction of a railway. There is no need
to build additional works, because the bus can use existing tunnels
and bridges
The "World Solar Challenge"
Also in 2005, the Nuon Solar Team has won (for the 3rd time) the
"World Solar Challenge". This is a contest (over 3000 kilometres) for
vehicles exclusively driven by solar energy. The Nuon Solar Team
has been formed by a number of students of the Technical University
of Delft, under the guidance of ex-astronaut Wubbo Ockels, they
have designed, or improved the "solar car". The fields of study of
these students are: Aerospace engineering, Mechanical engineering,
Industrial design and Computer science. The project has been
sponsored by Nuon and the Technical University of Delft.
The distance across Australia from North to South is 3021 kilometres.
The average speed has been 102,75 kilometres per hour.
Some technical data of the vehicle
|~ length 5 meters, width 1,8 metres and height 80 centimetres |
|~ total surface of the solar panels 8,4 square metres |
|~ frontal surface 0,79 square metres |
|~ air resistance 0,07 |
|~ weight 189 kilograms (excluding the driver) |
|~ gallium arsenate triple junction solar cells, with an efficiency |
|of up to 26% |
|~ efficiency of the (in-wheel) motor 97% |
|~ capacity of the lithium-ion polymer battery 5 kilowatt-hours, |
|at a weight of 30 kilograms |
In 2009 Japan won The World Solar Challenge. The decisive was given
by the indium-gallium-arsenate solar cells, developed by Sharp. These
solar cells had an efficiency of 30%.
In 2013 the Nuon Solar Team of the Delft university won the
World Solar Race for the fifth time
The Delft University of technology wins the first hydrogen
race in the world
On 23 August 2008 the first race with "hydrogen-karts" took place in
Rotterdam. Some data of the winning vehicle:
|~ the tank of the vehicle contains 5 litres of hydrogen at a pressure |
|of 200 bar |
|~ the top speed is 100 kilometres per hour |
|~ the vehicle accelerates in 5 seconds from standstill to |
|100 kilometres per hour |
|~ the continuous power of the fuel cell is 8 kilowatts |
|~ the vehicle is driven by 2 electric motors |
|~ each wheel has its own motor, which makes quick turns possible |
|~ the brake-energy is stored in "boost caps" (super caps) |
|~ during acceleration extra energy is extracted from the boost caps |
|~ the energy content of the boost caps is 56 watt-hours |
|(20 kilowatts during 10 seconds) |
The Shell eco-marathon
The Shell eco-marathon is an annual efficiency contest, sponsored by Shell. The goal is to trudge as many kilometres as possible with a vehicle on 1 litre
of regular petrol (Euro 95). So with 9100 watt-hours. There are 2 classes:
the "prototype" and the "urban-concept"
In the "prototype" class any form of the vehicle is allowed.
Usually it resembles a motorized recumbent
In the "urban-concept" class, the vehicle must resemble a car. The driver
has to sit upright and the vehicle must have four wheels.
Except petrol, also other energy sources may be used, such as:
|~ hydrogen via a fuel cell |
|~ solar energy through solar cells |
|~ diesel oil |
|~ LPG (liquefied petroleum gas) |
The results are converted to the petrol-equivalent. Hydrogen potentially
delivers a higher action radius than petrol. That is when the energy needed
for the production of hydrogen is neglected.
The efficiency of a fuel cell + electric motor is higher than of a petrol engine.
Important factors at the record attempts are:
|~ a low air resistance, so a small frontal area and a good flow line |
|~ a low weight |
|~ a low speed (the air resistance is proportional to the 2nd power |
|of the speed) |
|~ according to the rules of procedure, the average speed may not |
|be less than 30 kilometres per hour |
|~ an economical driving style |
|~ the transmission losses and the rolling resistance should be as |
|low as possible |
|~ the efficiency of the (small) engine must be as high as possible |
|(sometimes a Honda 4-stroke moped engine is used) |
In 2014 the following records have been achieved at the consumption of
1 litre of petrol:
|~ in the class "prototype 3316 kilometres (= 2,7 watt-hours per kilometre) |
|~ in the class "urban-concept 496 kilometres (= 19,4 watt-hours per kilometre) |
A streamlined recumbent
|~ the energy consumption (in the form of food) is |
|1 litre petrol equivalent per 1235 kilometres. |
|~ the net (mechanical) consumption is 4 times less |
|so 1 litre per 4940 kilometres. |
|~ that is theoretically feasible at an efficiency of 100% |
|~ at the Shell eco-marathon the record of the |
|"prototype" class is 1 litre per 2832 kilometres. |
|~ so with 12 litres petrol equivalent around the world. |
Bio fuel
|~ the efficiency of the transposition of solar energy to chemical |
|energy through photosynthesis is much less than 1% |
|~ the annual irradiation of solar energy in the Netherlands is |
|1000 kilowatt-hours, measured on a horizontal plane of |
|1 square meter |
|~ the annual yield of rapeseed oil is approximately 1700 litres |
|per hectare. |
|~ 1 hectare = 10.000 square meters |
|~ therefore the annual yield will be 0,17 litres per square metre |
|~ the primary energy content is 1,7 kilowatt-hours |
|~ if the by-products are also charged (press cake and straw) |
|one arrives at 3 kilowatt-hours, which is only 0,3% of the |
|amount of irradiated solar energy |
|~ after transposition into electric energy only 1,2 kilowatt-hours |
|remain, at an efficiency of 40% |
|~ the annual yield of an electric solar panel of 1 square meter |
|is 120 kilowatt-hours |
|~ so at the same surface and during the same time, an electric |
|solar panel will produce 100 times more electrical energy |
|than rapeseed oil. |
A better solution seems to be the production of bio-ethanol. That is
derived from sugar beet, sugar cane or maize, after fermentation.
The yield is 0,57 litres per square metre, with a primary energy content
of 3,5 kilowatt-hours. That is 2 times as much as of rapeseed oil.
Since September 2005 the oil companies are obliged to mix petrol and
diesel oil with 2% bio fuel in the Netherlands. One strives to 10% in 2020.
Press release on 9 October 2008:
"The Government will limit the use of bio fuels in petrol and diesel oil. It
was the intention that 4,5% of the oil next year should consist of rapeseed
and palms. That has been adjusted to 3,75%. The target for 2010 will also
be reduced, because it seems that the promotion of bio fuels will be
detrimental to the food production in poor countries”.
It is immoral and criminal to use precious agricultural land for (large-scale)
production of bio fuel to be able to drive our cars here, while in large parts
of the world famine is increasing. In addition, the effective emissions of
CO2 will hardly be reduced by the use of bio fuels.
The energy yield of wood production
A site where one can invest in wood, mentions:
|~ in 21 years the production of teak wood will be 400 cubic |
|metres per hectare. (somewhere in the tropics) |
|~ in 1 year that is 19 cubic meters of teak wood per hectare |
|~ 1 hectare = 10.000 square meters |
|~ 1 cubic meter of teak wood = 800 kilograms |
|~ the energy content of 1 kilogram of wood = 5,3 kilowatt-hours |
|~ at incineration of 19 cubic meters of wood |
|~ 19 × 800 × 5.3 = 80.000 kilowatt-hours is released |
|~ that is 8 kilowatt-hours per square meter per year |
|~ the energy irradiation by the sun in the tropics is |
|3000 kilowatt-hours per square meter per year |
|~ so the efficiency of wood cultivation will be |
|(8 / 3000) x 100% = 0,3 percent |
A few more things worth knowing
Hot-air Engine (Stirling engine)
|~ a hot-air engine is heated from the outside and |
|contains no valves. |
|~ therefore the reliability will be very good, while |
|the engine will be very quiet. |
|~ virtually all energy sources are suitable to heat |
|the engine, including solar energy or natural gas. |
Energy losses in the food cycle
|~ if a man eats grain, 10% will be converted into muscle proteins |
|~ if a pig eats grain, 10% will be converted into pork |
|~ if a man eats pork, 10% of it will be converted into muscle |
|proteins, so that is only 1% of the grain eaten by the pig. |
From the point of view of energy efficiency, eating of meat is very inefficient
Electric shaving in comparison to shaving with a razorblade
|~ shaving with a razorblade: warming up 200 centilitres of water |
|with 50 degrees costs 10 kilocalories = 11,6 watt hours |
|~ electric shaving: 2,8 watt-hours for 7 times of shaving, including |
|the charging cycle of the battery. = 0,4 Watt-hours at a time |
So shaving with a razorblade costs 11,6 / 0,4 = 29 times as much
energy as electric shaving.
Comparison of a hot pitcher with an electric blanket
|~ the content of a hot pitcher is 1,6 litres. Heating water from 10 to 80 |
|degrees Celsius = 1,6 × 70 = 112 kilocalories = 139 watt-hours |
|~ an electric blanket (1 person) = 25 watts |
|switched on the whole night (8 hours) = 200 Watt-hours |
Comparison of cooking on gas with electric cooking
At first glance cooking on gas seems to be much more efficient than cooking
on electricity, but at closer inspection this has to be nuanced a little
cooking on gas:
|~ much heat losses, because a lot of heat flows along the pan |
|~ combustion products (carbon monoxide and carbon dioxide) |
|in the kitchen |
|~ danger of gas leaks, which may cause life-threatening explosions |
|~ as a result in many buildings (Tower flats) cooking on gas is |
|prohibited |
|~ energy supply is (very) bad adjustable |
electric cooking:
|~ no combustion products in the kitchen. |
|~ the efficiency of the heat transfer between hob and pan |
|approaches the 100% |
|~ the energy supply is excellent adjustable |
|~ the energy supply can be automated, for instance setting the |
|desired temperature and stop heating when the water boils |
|~ a time switch can easily be applied (useful in elderly homes) |
Energy saving lamps
The use of energy saving lamps hardly saves energy. Because these
lamps are using "virtually no energy", people are inclined to let these
lamps burn all day and the lamps are hung up everywhere.
("rebound effect")
Reliability of the supply of electricity
It is commonly expected that the supply of electricity is guaranteed for
at least 99.99% of the time. Fortunately, in practise this is considerably
better. With a reliability of only 99.99% on average we would sit in the
dark during 53 minutes per year
Energy consumption of lighting
The energy consumption of the lighting is approximately 15% of the total
electricity consumption of a household. If the heating of the home and the
use of the car are included, the share of lighting will be only 4%. If one
really wants to save energy, it is better to set the heating somewhat lower
and to abolish the car, than switching off the lighting in the kitchen every
now and then. Small bits only help a (very little) bit.
If everyone does a little, we’ll achieve only a little
Also it will have little effect to reduce the lighting of highways (to save
energy) while the car traffic is unaffected.
In the Netherlands households consume 27% of the total quantity
of primary energy
|~ in 2008 the consumption of primary energy of all households |
|was 254 billion kilowatt-hours, including the heating of houses |
|and the use of cars. |
|~ the total primary energy consumption, including industry, |
|transport and public transport, was 927 billion kilowatt-hours. |
So the households consumed 27% of the total amount of primary energy
In 2008 the Netherlands consumed 0,65% of the world energy
|~ the consumption of primary energy in the Netherlands |
|was 927 billion kilowatt-hours. |
|~ the world consumption of primary energy was |
|142.670 billion kilowatt-hours. |
Therefore the Netherlands consumed 0,65% of the world energy
A Dutchman consumes 53 times as much energy as needed to stay alive
|~ on average the consumption of food of 1 Dutchman is |
|2500 calories per day, which equals 3 kilowatt-hours per day. |
|~ in 2008 the consumption of primary energy was 927 billion |
|kilowatt-hours. |
Converted to 1 person per day the consumption was about 160 kilowatt-
hours That is 53 times as much energy as needed to stay alive and
equivalent to the energy-contents of 18 litres of petrol. Inhabitants of
Africa must live on 13 kilowatt-hours per day.
During his lifetime a Dutchman consumes almost as much energy as
a Jumbo jet, that flies one time around the Earth
|~ the energy consumption of a Dutchman is 18 litres of petrol- |
|equivalent per day |
|~ in 80 years that amounts to: 80 × 365 × 18 = 525.600 litres |
|of petrol-equivalent |
|~ that causes 1500 tonnes of CO2 |
|~ a Jumbo jet consumes 600.000 litres of kerosene for a flight |
|of 40.000 kilometres. (= the circumference of the Earth) |
In 2011 the 7 billionth earthling was born
Suppose that we count the number of people on Earth with a speed
of 1 per second Then 222 years of counting will be needed:
(1 year = 8760 hours × 3600 seconds = 31,5 million seconds)
Press release on 14 January 2008:
"In 2010 there will be 1 billion cars and trucks driving around on Earth
Currently, there are 942 million vehicles worldwide. Achieving 1 billion
vehicles in 2010 is only an intermediate phase.
Despite the environmental problems the fleet grows in 2015 to
1,124 billion units ".
Overview of the main locations where fossil fuels are found
(percentages)
| |Middle |Africa |North |South |Asia and |Eastern |West |
| |East | |America |America |Oceania |Europe |Europe |
|coal | |6,9 |37,3 |3,1 |35,4 | 6,1 |11,2 |
|oil |62,1 |6,3 | 7,4 |7,9 | 3,8 | 9,8 | 2,7 |
|natural gas |32,5 |6,4 | 5,5 |3,9 | 9,3 |37,3 | 5,2 |
Energies worldwide
(per year and converted into kilogram-mass equivalent)
| electricity consumption = 800 kilogram-mass equivalent |
|total primary energy = 5600 kilogram-mass equivalent |
|irradiated solar-energy = 44 million kilogram-mass equivalent |
Some units
Watt peak
Watt peak is the electrical power of a solar panel, at an irradiation of
1000 watts per square meter and a panel temperature of 25 degrees
Celsius
For example:
|~ at an efficiency of 12% (current state of the art) the |
|electrical power of a solar panel of 1 square metre |
|will be 1 × 1000 × 12% = 120 watt peak. |
The theoretical yield of 1 watt peak is 1 x 8760 = 8760 watt-hours.
In the Netherlands the annual yield of 1 watt peak is approximately
850 watt-hours. This is caused by the following circumstances:
|~ the production factor of solar energy in the Netherlands is 11,4% |
|~ the efficiency of a solar panel depends on the irradiated power |
|and on the panel temperature. (the warmer the worse). |
|~ a solar panel will be subject to aging and pollution. |
|~ in addition, losses can be experienced in the "inverter" |
|The inverter is a circuitry that converts the low direct voltage |
|from the solar panel into an alternating voltage of 230 volts |
|This enables feed back of the solar energy into the grid. |
|~ a fixed solar panel almost never is mounted under the ideal |
|angle of 36 degrees and exactly facing South. |
So in the Netherlands the annual yield of a 120 watt peak solar panel
will be 120 x 850 watt hours = 192.000 watt hours = 102 kilowatt hours
On average that will be 102.000 / 365 = 280 watt hours per day
1 kilocalorie = 427 kilogram-metres = 1,16 watt-hours
1 kilocalorie is the amount of energy required to raise the temperature
of 1 kilogram of water with 1 degree Celsius
|~ the meltdown of 1 kilogram of ice of 0 degrees Celsius costs |
|80 kilocalories |
|~ to bring to the boil 1 kilogram of water of 0 degrees costs |
|100 kilocalories |
|~ to fully evaporate 1 kilogram of water of 100 degrees costs |
|540 kilocalories That is (coincidentally?) 3 times as much |
|as needed for melting + bring to the boil |
1 mtoe = 11,63 billion kilowatt-hours
1 mtoe (mega ton oil equivalent) is the amount of energy produced by the
burning of 1 million tonnes of crude oil.
(so 2 mtoe is almost as much energy as 1 kilogram-mass equivalent)
1015 btu = 293 billion kilowatt-hours
1 btu (British thermal unit) is the amount of energy required to raise the
temperature of 1 pound (= 0,45 kilograms) of water with 1 degree Fahrenheit
(= 0,56 degree Celsius)
1 btu = 0,252 kilocalories
Tables and graphs
World production of primary energy in 2006
(distribution by energy sources)
| |1015 btu |percentage |
| oil |169 | 36 |
| natural gas |107 | 23 |
| coal |129 | 28 |
| hydro power | 30 | 6 |
| nuclear energy | 28 | 6 |
| wind, Sun, biomass etc. | 5 | 1 |
| total world |468 |100 |
World production of primary energy in 2006
(distribution by energy source)
[pic]
One may be "against coal", but that does not alter the fact that
28% of the world production of primary energy comes from coal.
World consumption of primary energy in 2006
(distribution by continent)
| |1015 btu |percentage |
| North America |121 | 26 |
| Central en South America | 24 | 5 |
| West Europe | 86 | 18 |
| Eastern Europe | 46 | 10 |
| Middle East | 24 | 5 |
| Africa | 15 | 3 |
| Asia and Oceania |156 | 33 |
| total world |472 |100 |
World consumption of primary energy in 2006
(distribution by continent)
[pic]
Consumption of electricity and the total consumption of primary energy in 2008
(billion kilowatt-hours)
| |electricity- |total primary |
| |consumption |energy consumption |
| Netherlands | 109 | 927 |
| China | 2.842 | 24.614 |
| USA | 3.814 | 26.560 |
| World |16.816 |142.670 |
Distribution of the electricity consumption in the Netherlands in 2008
| |billion |percentage |
| |kilowatt-hours | |
| industry | 43,8 | 40,1 |
| households | 24,8 | 22,7 |
| services | 32,8 | 30,0 |
| agricultures | 7,8 | 7,2 |
| total |109,2 |100,0 |
Distribution of the electricity consumption in the Netherlands in 2008
[pic]
Total primary energy consumption per inhabitant per day in 2006
(distribution by continent)
| |number of inhabitants |energy consumption |
| |(x 1 million) |(kilowatt hours) |
| North America | 439 |221 |
| Central en South America | 454 | 42 |
| West Europe | 591 |117 |
| Eastern Europe | 285 |130 |
| Middle East | 187 |103 |
| Africa | 914 | 13 |
| Asia en Oceania |3.649 | 34 |
| total World |6.519 | 58 |
Overview of the energy sources for generating electricity in some countries (2009)
(billion kilowatt-hours)
| |nuclear- |hydro- |wind- |solar- |geotherm. |coal, oil, |total |
| |energy |power |energy |energy |biomass |natural gas | |
| Netherlands | 4,2 | 0,1 | 4,6 | 0,05 | 7,8 | 96,8 | 113,5 |
| Belgium | 47,2 | 1,8 | 1,0 | 0,17 | 5,3 | 35,7 | 91,2 |
| Germany | 134,9 | 24,7 | 38,6 | 6,58 | 41,9 | 345,7 | 592,5 |
| United Kingdom | 69,1 | 8,9 | 9,3 | 0,02 | 12,4 | 275,9 | 375,7 |
| France | 409,7 | 61,9 | 7,9 | 0,17 | 6,1 | 55,9 | 542,2 |
| Switzerland | 27,7 | 37,5 | 0,0 | 0,05 | 2,4 | 0,8 | 68,5 |
| Italy | 0,0 | 53,4 | 6,5 | 0,67 | 10,0 | 216,6 | 292,6 |
| Spain | 52,8 | 29,2 | 37,8 | 6,04 | 4,5 | 163,6 | 293,8 |
| Sweden | 52,2 | 66,0 | 2,5 | 0,00 | 12,2 | 3,9 | 136,7 |
| Norway | 0,0 | 127,1 | 1,0 | 0,00 | 0,4 | 4,4 | 132,8 |
| Denmark | 0,0 | 0,0 | 6,7 | 0,00 | 4,0 | 25,6 | 36,4 |
| Russia | 163,6 | 176,1 | 0,0 | 0,00 | 3,1 | 649,2 | 992,0 |
| Africa | 12,8 | 101,3 | 1,7 | 0,03 | 2,2 | 514,9 | 632,8 |
| Japan | 279,8 | 82,1 | 3,0 | 2,80 | 24,3 | 656,0 | 1047,9 |
| China | 70,1 | 615,6 | 26,9 | 0,32 | 2,4 | 3019,2 | 3734,7 |
| Australia | 0,0 | 12,3 | 3,8 | 0,27 | 2,8 | 241,8 | 260,9 |
| USA | 830,2 | 298,4 | 74,2 | 2,50 | 72,9 | 2892,9 | 4188,2 |
| World |2696,8 |3329,2 |273,2 |21,00 |298,2 |13447,2 |20132,2 |
Overview of the energy sources foe generating electricity in some countries (2009)
(percentages)
| |nuclear- |hydro- |wind- |solar |geotherm |coal, oil, |total |
| |energy |energy |energy |energy |biomass |natural gas | |
| Netherlands | 3,7 | 0,1 | 4,1 |0,04 | 6,9 |85,3 |100 |
| Belgium |51,8 | 1,9 | 1,1 |0,18 | 5,9 |39,2 |100 |
| Germany |22,8 | 4,2 | 6,5 |1,11 | 7,1 |58,4 |100 |
| United Kingdom |18,4 | 2,4 | 2,5 |0,01 | 3,3 |73,4 |100 |
| France |75,6 |11,5 | 1,5 |0,03 | 1,1 |10,3 |100 |
| Switzerland |40,5 |54,8 | 0,0 |0,07 | 3,5 | 1,1 |100 |
| Italy | 0,0 |18,3 | 2,2 |0,23 | 5,2 |74,0 |100 |
| Spain |18,0 | 9,9 |12,9 |2,06 | 1,5 |55,7 |100 |
| Sweden |38,2 |48,3 | 1,8 |0,00 | 8,9 | 2,8 |100 |
| Norway | 0,0 |95,7 | 0,7 |0,00 | 0,3 | 3,3 |100 |
| Denmark | 0,0 | 0,1 |18,5 |0,01 |11,1 |70,4 |100 |
| Russia |16,5 |17,8 | 0,0 |0,00 | 0,3 |65,4 |100 |
| Africa | 2,0 |16,0 | 0,3 |0,00 | 0,1 |81,4 |100 |
| Japan |26,7 | 7,8 | 0,3 |0,26 | 2,3 |62,6 |100 |
| China | 1,9 |16,5 | 0,7 |0,01 | 0,1 |80,8 |100 |
| Australia | 0,0 | 4,7 | 1,5 |0,10 | 1,1 |92,7 |100 |
| USA |19,8 | 7,1 | 1,8 |0,06 | 1,7 |69,1 |100 |
| World |13,4 |16,5 |1,4 |0,10 | 1,5 |66,8 |100 |
Energy sources for generating electricity worldwide
[pic]
green energy = wind, Sun, geothermal, wood and biomass
Wind energy en solar energy in some countries (2009)
(billion kilowatt-hours)
| |wind energy |solar energy |
| Netherlands | 4,6 | 0,05 |
| Germany | 38,6 | 6,58 |
| Spain | 37,8 | 6,04 |
| China | 26,9 | 0,32 |
| USA | 74,2 | 2,50 |
| World |273,2 |21,00 |
Compared to other countries very little solar energy is generated in the Netherlands.
Germany generates 31% of the world production of solar-energy. This is 132 times
as much as the Netherlands. Spain is second best with 29% of the world production.
An actual overview of the production of solar energy in Germany can be found at:
Overview of the growth of green energy in the generation of electricity in
some countries, from 1990 to 2008
(percentages)
| |1990 |1994 |1998 |2002 |2004 |2006 |2008 |
| Netherlands |1,4 |2,2 | 5,1 | 5,6 | 6,9 | 9,6 |10,3 |
| Belgium |1,0 |1,4 | 1,3 | 2,1 | 2,3 | 4,5 | 6,2 |
| Germany |0,9 |1,5 | 2,4 | 5,1 | 7,0 | 8,6 |11,7 |
| United Kingdom |0,5 |1,5 | 1,1 | 1,8 | 2,2 | 4,1 | 4,6 |
| France |0,5 |0,5 | 0,6 | 1,0 | 1,1 | 1,4 | 2,0 |
| Switzerland |1,0 |1,5 | 1,9 | 2,3 | 3,0 | 3,8 | 3,5 |
| Italy |1,6 |1,8 | 2,5 | 3,8 | 4,6 | 5,2 | 6,0 |
| Spain |0,5 |0,6 | 1,9 | 5,1 | 8,0 |10,2 |12,5 |
| Sweden |1,3 |1,6 | 2,1 | 3,4 | 4,8 | 7,3 | 8,8 |
| Norway |0,2 |0,3 | 0,3 | 0,4 | 0,7 | 1,1 | 1,0 |
| Denmark |3,3 |4,9 |10,6 |19,1 |25,6 |21,8 |29,7 |
| Africa |0,1 |0,1 | 0,2 | 0,2 | 0,4 | 0,5 | 0,5 |
| Japan |2,1 |2,1 | 1,8 | 2,1 | 1,5 | 2,5 | 2,7 |
| China |0,0 |0,0 | 0,2 | 0,2 | 0,1 | 0,2 | 0,5 |
| Australia |0,4 |0,4 | 0,6 | 0,9 | 1,1 | 1,5 | 2,5 |
| USA |2,2 |2,5 | 2,2 | 2,4 | 2,4 | 2,7 | 3,1 |
| World |1,2 |1,4 | 1,5 | 1,9 | 2,0 | 2,3 | 2,5 |
green energy = wind energy, solar energy, geothermal energy and biomass
Overview of the growth of the electricity consumption in some countries,
(billion kilowatt-hours and the growth in percentages)
| |1990 |2008 |growth |
| Netherlands | 73 | 108 | 48 |
| Belgium | 59 | 85 | 44 |
| Germany | 502 | 637 | 27 |
| United Kingdom | 286 | 389 | 36 |
| France | 324 | 575 | 77 |
| Switzerland | 47 | 69 | 47 |
| Italy | 220 | 319 | 45 |
| Spain | 130 | 314 |142 |
| Sweden | 130 | 150 | 15 |
| Norway | 98 | 143 | 46 |
| Denmark | 29 | 36 | 24 |
| Africa | 276 | 624 |126 |
| Japan | 777 | 1082 | 39 |
| China | 549 | 3495 |537 |
| Australia | 136 | 257 | 89 |
| USA | 2837 | 4369 | 54 |
| World |10407 |20261 | 95 |
Alternative energy sources
Anything can be calculated, but that does not mean that it can be
achieved in practice, or that it is economically feasible
The following forms of alternative energy have in common, that they have not
(yet) been realized. Often they are fantasies, more than practicable projects.
A good example of this is the "solar Tower". which should have a height of
1 kilometre. The highest building in the world (in Dubai) is 828 metres high.
The efficiency of the solar tower is 1,5%
A 600 megawatt power plant produces 6 times as much energy in 1 year
Solar Tower
[pic]
Solar radiation warms the air located under a low circular, translucent collector.
This collector is open at the border. The translucent roof of this collector
together with the ground is a storage space for the heated air. A tower is stated
in the centre of the round roof. The heated air rises in this tower. As a result
new cold air enters on the edge of the storage space. At night also there is a
continuous flow of warm air to the tower, because the entire ground surface
consists of tubes filled with water. At daytime these tubes are being heated
and at night they release their heat again. In the air flow to the tower a number
of wind turbines are placed. The associated generators generate electricity.
It is possible that such a tower might be built in Australia.
Some data: (rounded)
|~ the temperature of the air under the collector rises 30 degrees |
|~ the speed of the airflow at the foot of the tower is 60 kilometres |
|per hour |
|~ the capacity (power) is 200 megawatts |
|~ the annual production is 680.000 megawatt-hours |
|~ the tower is 1 kilometre high and the diameter is 130 metres |
|~ the diameter of the round collector is 5 kilometres |
|(so the radius r = 2500 metres) |
|~ at the foot of the tower there are 32 turbines of 6,5 megawatts |
Calculation of the return
|~ the surface of the collector is π r2 = 3,14 × 25002 = |
|19.625.000 square meters. |
|~ the annual radiant energy from the Sun in Australia is |
|2,3 megawatt-hours per square meter. |
|~ so the total amount of energy transmuted in the |
|collector will be 45.137.500 megawatt-hours per year. |
|~ so the efficiency will be |
|(680.000 / 45.137.500) × 100% = 1,5%. |
|~ compare the efficiency of an electric solar panel = 12% |
The advantages of the solar tower are:
|~ there is virtually no maintenance required |
|~ no (water) cooling is needed |
|(a great advantage in dry and warm areas) |
|~ the installation works on the heat irradiated by the |
|Sun and therefore it has little burden of pollution |
|~ the energy supply during day and night is |
|(more or less) continuous |
Blue Energy
Blue Energy is a form of generation of sustainable energy based on the difference in
salt concentration of seawater (salt) and river water (fresh). By building a "generator"
that consists of plastic membranes (a kind of filters) on the border area some energy
might be won. The technique used is called "reverse electro dialysis". The water on
one side of the membrane is charged positively, on the other side negatively. The
voltage difference is 80 milli volts. Enough voltage may be obtained for a practical
application through stacking of a large number of membranes. The system works as
a kind of battery. There is no other energy source than fresh and salt water.
Theoretically the yield should be sufficient for the electricity supply of the Northern
part of the Netherlands, if all the fresh water that flows through the Netherlands in
sea, would be used for this form of energy-generation.
An unrealistic and implausible story.
Ladder Mill
The ladder mill consists of a system worn by the wind. There are a large number
of wings that are bound to a strong rope that forms a loop. One end of the loop
gives power to a dynamo on the ground. The wings are set as blades in such a way
that along one side of the loop the wings move upward under the influence of the
wind. Beyond the top high in the air, the wings along the other side of the loop
move down again. This is achieved by altering the state of the wings, by which
they suffer an upward or downward pressure. This creates a spinning movement
of the loop. The energy yield of the ladder mill is said to be at least 50 times
more than of an ordinary windmill with a capacity of 1 megawatt.
This doesn't seem to be very realistic.
The Maglev wind turbine
[pic]
Maglev is the abbreviation of magnetic levitation. The Maglev wind turbine has
a vertical axis. The axis and the "blades" are resting on a magnetic bearing.
A magnetic bearing is virtually frictionless. (but does consume energy).
Due to the very low friction, this wind turbine already provides a useful
amount of energy at an air speed of 3 meter per second. Very high wind speeds
do not constitute a problem, the mill can continue to run. Therefore, according
to the Chinese inventors, this type of wind turbine may provide 20% more energy
in comparison with a conventional wind turbine of the same power. One has to
guess how the magnetic bearing works. It is unclear how it should be built with
permanent magnets and the use of no electrical energy for the "levitation".
Therefore this seems to be a very unlikely story, In some publications imagination
is being used freely. This mill should be 1000 times more efficient than a
regular wind turbine.? One must be very naive to believe this kind of crap
Perhaps it is meant, that the friction in the bearings of this mill will be
1000 times lower than in an ordinary mill. The friction of the bearings normally
consumes only a few percents of the energy that is generated by a wind turbine.
Therefore very little profit can be achieved. Interesting is the vertical axis,
causing this mill to be insensitive for the direction of the wind, while very
large constructions are possible. The wind energy is exited over the entire
height of the mill. This kind of constructions has already been known many years
(centuries). The mill would have monstrous dimensions, (like 600 metres high,
with a diameter of 400 metres) and then generate just as much energy as
1000 ordinary windmills.
Wave energy
Wave energy is energy won from the rapidly changing water height at sea by
the presence of waves. Although theoretically (very much) energy can be won,
until now it has not been done on a large scale because the costs usually
exceed the benefits. Off the coast of Portugal the first commercial wave
plant will be build. A plant that converts energy from ocean waves into
electrical energy. The system will generate enough electricity for (only)
1500 households.
Energy radiation from space
To make this possible, huge solar panels must be brought in a geostationary
orbit around the Earth. The absorbed solar energy is than beamed down by
means of microwaves and converted into electricity. An insane plan, which
of course will never be realized. (fun for James Bond movies)
Free energy
|[pic] | |
| | |
| | |
| |Tesla |
In this enumeration of alternative energy sources, the indication of "free energy"
must be mentioned. There is no scientific basis for the existence of "free energy"
However, one can have vague doubts, because Tesla would have invented this
in 1889.
Tesla (1856-1943) was one of the greatest inventors of all time. Among other
things he designed the infrastructure of electricity networks as we are currently
using everywhere. This is energy transport by means of alternating current
transported through high tension power lines and transformers. He also was the
inventor of the alternating current induction motor, the fluorescent tube, the radio
and the remote control. In 1943, shortly after his death, the American Supreme
Court officially established that Tesla was the inventor of the radio and therefore
not Marconi. His greatest invention however would be the global energy supply
by "free energy", drained from the "ether". However, experiments with this have
never taken place because his lenders left failed. They saw nothing in free energy
|[pic] | |
| | |
| |The Warden Clyff Tower |
| |With 5 of these towers Tesla would make a |
| |worldwide, wireless energy supply possible |
Tesla was able to transport energy wireless over great distances. It was stated
that he left lamps burning wireless at a distance of several hundred metres. He
also would have converted an electric car, that could drive for a week without
charging the battery. This would also be made possible by the wireless transfer
of energy.
The wireless transmission of energy in itself is nothing special. Virtually all the
energy we use on Earth is transferred wirelessly from the Sun to the Earth.
An electric 2-seater sports car was named "Tesla Roadster". This car is
powered by a 3-phase alternating current induction motor. The principle of
this motor was invented by Tesla in 1888.
Storage of Energy
Some forms of storage of energy
|~ electric energy in super capacitors |
|~ chemical energy in batteries and hydrogen |
|~ thermal energy in materials with a large heat capacity |
|~ kinetic energy in flywheels |
|~ potential energy by moving mass against gravity |
|to a higher level or by compressing air |
| Electric energy |
Electric energy may be stored in the form of electric charge in a super capacitor.
Super capacitors can be charged and discharged very fast with high peak currents.
In hybrid and electric cars super capacitors can be used for saving the brake-
energy quickly and effectively, while that energy than is available again quickly in
acceleration. The energy content of a super capacitor is relatively small, while the
tension rapidly declines during the discharge. However, recent developments are
promising. There are already modules with super caps on the market, which have
an energy content of 282 watt-hours at a capacity of 17,8 farad and a voltage of
390 volts. Also there are plans for a super capacitor with an energy content of
52 kilowatt-hours. In the long term the super capacitor might replace the battery
in certain applications. The lifetime is virtually unlimited, while the efficiency of the
charging cycle is very high, about 97%.
| Chemical energy |
In batteries and accumulators, but also at the production of hydrogen gas,
Electrical energy is stored in the form of chemical energy.
batteries and accumulators
Batteries and accumulators are relatively cheap and reliable. The efficiency of the
charging cycle is quite high, approximately 85%. On the other hand, batteries and
accumulators are overweight and they need much room, while the capacity is
limited. Also the long charging time or the huge charging current often consist a
problem.
hydrogen gas
The production of hydrogen gas and recovery of electricity in a fuel cell is
accompanied by a bad (total) efficiency. Although the energy content of hydrogen
per unit of weight is large, (33,6 kilowatt-hours per kilogram) the volume is also
(very) large, even if the gas is strongly compressed. Compressing takes a lot of
energy. Hydrogen is only liquid at 252 degrees Celsius below zero. Therefore
liquefaction is not an option. However, it seems possible, to store hydrogen
efficiently in metal hydrides or gas hydrates using nano technology. The use of
hydrogen is potentially dangerous . (ox hydrogen). Chemical compounds of
hydrogen and carbon are problem-free. That are the well known hydrocarbons
like natural gas and synthetic petrol
| Thermal energy (Heat) |
Heat storage can take place in material with a high heat capacity, for example in
water (solar boiler), or in layers at any depth in the ground. (aquifers). Usually it
concerns relatively low temperature levels, which cannot be used for the production
of electricity. However, the stored heat can be used for heating purposes using heat
pumps. At a Sun thermal power plant for (short-lived) storage of the solar-energy,
molten salt is used. With the stored heat electricity can be produced during sunless
periods
| Kinetic energy |
Kinetic energy can be stored in a flywheel. The storage capacity is pretty small.
A flywheel can be used for slowing down a vehicle. Then the kinetic energy is
stored in the flywheel. The energy will be used again for acceleration. This is
applied in some city buses
| Potential energy |
Potential energy can be obtained by moving mass to a higher level. For example by
pumping water to a higher located reservoir. This often happens at hydroelectric
plants. For pumping, the excess energy is used that is available in the valley hours.
In times of drought, the potential energy, which is stored in the reservoir, can be
converted again in electrical energy by the hydroelectric plant The efficiency of this
form of energy storage is quite high, approximately 75%. Another form of potential
energy arises, if one uses compressed air Compressed air can be used for the
propulsion of tools and even cars.
Some possibilities for storage of energy (rounded)
| |watt-hours |watt-hours |efficiency of the |
| |per kilogram |per litre |storage cycle |
| petrol (for comparison) |12.600 |9.100 |- - |
| hydrogen 200 atmosphere |33.600 | 600 |40% |
| lithium-ion polymer battery | 200 | 300 |99% |
| compressed air 200 atmosphere | 90 | 23 |low |
| vanadium redox battery | 20 | 25 |80% |
| gravity power 500 metres | 1 | 8 |80% |
Energy saving
The largest profits in energy saving can be achieved in the insulation and heating of
the home and in the use of hot water. Followed by the car and finally lighting.
Insulation of the house
Annually an average of 2150 cubic meters of natural gas will be required to heat a
poorly insulated house. A good insulated house does not need more than 700 cubic
meters. So insulation really helps a lot.
Heating of the house
The principle of Combined Heat and Power (CHP) can also be applied in the
heating of a dwelling. A good example of this is the Hee boiler (high efficiency
electric) This boiler contains a hot-air engine that generates electricity. The excess
electricity is delivered back to the grid. The total efficiency is more than 90%. If all
homes should be equipped with such a boiler, then perhaps less electric power
plants would be needed. Because the efficiency of a conventional power plant is
only 40%, large scale application of the Hee boiler might save a significant amount
of energy. Thus a reduction of CO2 emissions might be achieved. A problem
however is, that in summer this system will not work (only for the heating of
water), because then one usually wants cooling rather than heating. The total
installed capacity of electric power plants will therefore probably not be much
smaller. Calculated over the entire year the energy supply of the plants might be
less.
Hot water
The (pre)heating of water can take place using high efficiency (65%) solar
collectors. When showering one can restrict the consumption of hot water a little
by using a water-saving showerhead. Taking a bath once costs 120 litres of water
Showering once takes half as much. (7,5 litres of water per minute, for 8 minutes).
A water saving showerhead consumes 7,5 litres of water per minute, an ordinary
showerhead 8,2 litres. Much saving in energy can be achieved by placing the water
boiler as close as possible near the tap, as well in the kitchen as in the shower. In
many homes a combi boiler is in the attic. That is the worst place imaginable. When
hot water is needed, the long branch to the kitchen or bathroom must be warmed
up before the water on the consumable place gets the desired temperature. After
closing the tap the water cools in the water pipe again, what means pure energy
losses. It also costs a lot of water.
Car
One can achieve a considerable saving in fuel by driving a hybrid car. This can save
up to 25%. Of course the only real saving is the abolition of the car. Unfortunately,
public transport is of such poor quality, that this is a difficult step to take. Only an
extreme increase in the petrol price, for example up to € 5,- per litre, will have any
effect on the long term, but most people are addicted to their car.
The most fuel-efficient 4-seater car with a petrol engine, and a speed of
100 kilometres per hour can never reach a more economical rate than 1 litre per
40 kilometres. One can calculate this on the basis of the lowest conceivable air
and rolling resistance, combined with the highest conceivable efficiency of a petrol
engine. Consumption of 1 litre per 40 kilometres has been announced for the new
plug-in Prius, which will be launched in 2012.
(Apparently one is “forgotten” that part of the time this car runs on electricity.)
For comparison: the vehicle on solar energy – the Luna4 - that won the "World
Solar Challenge " has a consumption (converted to petrol-equivalent) of 1 litre per
70 kilometres. This vehicle only has room for 1 person in half reclining posture.
Lighting
Although lighting consumes very little energy, one can save a bit by the consistent
use of energy saving lamps. In the near future perhaps also LED-lamps will play a
role in energy savings
The collapse of the oil-economy
[pic]
Civilization as we know it today will soon come to an end, because we will run out
of oil. That is a scientifically based conclusion. The oil will not suddenly be gone,
because its production follows a bell-shaped curve. On the ascending side of the
curve cheap oil is available in increasing extent. On the descending side there is less
oil, which is becoming increasingly more expensive. The top of the production
coincides with the point, where half of the oil has been consumed. After the peak,
the production takes off and the costs increase because it is harder to win the oil.
Moreover scarcity has a very strong effect in rising the price. Yet this year (2007)
the world oil consumption will exceed 1000 barrels per second. That equals
86 million barrels per day. (1 barrel = 159 litres)
Suppose that the top of the production has been achieved in the year 2000, Then
as much oil as in 1980 will be produced in 2020. In the meanwhile, the world's
population has been doubled and is furthermore becoming increasingly dependent
on oil. The result is, that the worldwide demand for oil in 2020 will exceed its
production by large. The oil price then will explode to about 400 dollars per barrel.
Oil-dependent economies will collapse and probably wars will break out
The coming oil scarcity is the beginning of a new everlasting state. The decrease
in oil production will be approximately 7% per year. That is 50% in 10 years. The
general expectation is that in the near future serious problems will arise
The price development of the crude oil
|year |dollars per barrel |
|1973 | 3 - 12 |
|1998 |10 - 15 |
|2000 |24 - 37 |
|2002 |20 - 28 |
|2004 |30 - 51 |
|2006 |58 - 80 |
|2007 |53 - 99 |
|2008 |32 - 146 |
|2009 |32 - 81 |
|2010 |67 - 92 |
|2011 |75 - 115 |
|2012 |77 - 110 |
|2013 |86 - 110 |
|2014 |92 - 107 |
Press release on 20 December 2007:
"The NAM (a Dutch Petroleum Society) reverts to win oil in Schoonebeek.
Over the next 25 years certainly 100 million barrels can be produced".
The world consumption of oil is 1.000 barrels per second. The production
of Schoonebeek in 25 years is therefore sufficient for the world consumption
of 100.000 seconds = 28 hours
How will the future look?
Oil
We are running out of oil. For the last 15 years no major oil fields have been found
Therefore in Canada and Venezuela the difficult extractable oil from tar sands will
be exploited. For oil drilling one goes to a depth of 5 kilometres in the Gulf of
Mexico. The price of crude oil will rise rapidly. Oil drilling in Schoonebeek has
started anew.!
Not everyone is convinced that oil is a fossil fuel and that it will run out eventually
NRC-Handelsblad 9 December 2011:
"Oil enough". Shell estimates the stock of oil off the coast of Alaska on 25 billion
barrels. That is sufficient for at most 10 months of the world's oil consumption
Gas
There is still sufficient gas, and that will last probably for the next 60 years. The top
of gas production will be reached in about 20 years. Then the price will rise
strongly. West Europe will be particularly dependent on Russia, Norway, North
Africa and the Middle East.
Volkskrant 5 December 2006:
"Under unaltered conditions the gas reserves (in the Netherlands) will be exhausted
in 2030"
NRC-Handelsblad 14 July 2010:
"After shortage now a surplus of natural gas". New technology has revolutionised
the world of natural gas. Huge stocks of gas from coal and compact shale layers
come within range, among other in America. The result is overproduction.
Shell is working worldwide on projects to use gas for the manufacture of a kind
of diesel oil. GTL = Gas to liquids, a variant on the Fischer-Tropsch process.
Coal
Worldwide coal is available for at least 200 years. Coal is good for everything. It
can be used to make City gas, hydrogen, synthetic petrol and diesel oil. In addition
very much CO2 is released. But no objections will be raised if there is shortage of
energy. The technique for the production of synthetic petrol from coal has been
known since 1923. It was applied by Germany on a large scale during the
2nd World War. (Fischer-Tropsch synthesis)
Hydropower
Although the most profitable projects have been realized already, there are still
great opportunities in Africa and South America. Hydroelectric power plants
cause a lot of damage to the environment.
Dutch Teletext 4 March 2011:
In Brazil, the preparations for the construction of the largest hydroelectric power
plant in the world are being continued. The power plant is situated in the north of
the Amazon region. The local population and the environmental organisations are
opposing vehemently. The construction would cause homelessness for tens of
thousands of people. The Government stresses that the dam can deliver sufficient
energy for 23 million households and it will create many jobs
Green energy
Green energy obtained from wind, solar, biomass etc. will be of little meaning
provisionally. It is believed this will be up to 15% (in the Netherlands) of (only)
the electricity in 2020 Wind energy is still in an initial state in some countries.
Solar energy is still negligible. One should think of no more than a few thousandths
of the total electricity generation. In 2009, the world production of solar energy
was only 0,1%
Bio fuel
Large-scale production of bio diesel etc. comes at the expense of the long-term
food production. In addition, it will cost much fossil fuel. This is not a real option.
The conversion of solar energy into bio fuel is accompanied with an extremely low
efficiency, in the order of 1%
Nuclear Energy
Nuclear energy at the current consumption can last us for the next 75 years. When
Uranium has been run out, a solution might be to apply breeder reactors. Than we
would have enough Uranium to carry on for 5000 years. (only for the electricity
generation) If the Uranium has run out, probably one can continue with Thorium.
Thorium can be "burned" completely in simple reactors. This is in contrast to
Uranium, of which only 0.7% can be used. (the isotope U235). In India already
some Thorium reactors are operational. In future Thorium will probably be the
most important nuclear fuel. The amount of Thorium on Earth is 3 times as large as
the amount of Uranium.
Nuclear Fusion
We may expect the first practical results of nuclear fusion around 2050. Then
mankind can have an infinite amount of "clean" energy. The total development time
then has seized about 100 years. One might wonder whether one will ever succeed
in generating very large quantities of energy by means of controlled nuclear fusion.
Until now a technical development has never taken so long. For example,
electricity, radio, (satellite)television, airplane, computer, aerospace, laser, nuclear
energy, hydrogen bomb etc. have all been achieved in a period of some decades,
from an idea to a product that can be used
Hydrogen
Hydrogen can be produced using nuclear energy via a thermo-chemical process or
by electrolysis of water. The necessary electricity for the electrolysis of water must
be generated by nuclear fusion, or by "green" energy. But that is still a long way to
go. Hydrogen is an "unruly" fuel, for which no infrastructure exists. The fuel cell is
still far too expensive and requires much development yet. Hydrogen is not an
energy source, but an energy carrier. Producing hydrogen by electrolysis of water
costs 1.5 times more energy than it delivers
Hydrogen? that will (virtually) be nothing
How long can we continue with fossil fuels?
According to some experts, there is still sufficient gas and coal for the next
400 years. But then it is necessary to use all sources, also those that are difficult
to reach. Oil will run out within the foreseeable future (about 50 years). Nuclear
energy and renewable energy sources (Sun and wind) will continue to provide a
very limited contribution. Nuclear fusion is only mentioned in passing. A drastic cuts
in energy consumption and a higher efficiency in the generation of electricity might
be a solution. One must also fully exploit all the residual heat from power plants
There is a mismatch between the production and consumption of energy. There
would be almost no problem, if there were a few billion people less walking
around. (driving around) on this earth. Reality is that a few billion people more are
to come before the year 2050.
That will be an increase of 1 million people per week on average.
The only solution seems to be: a strong cut down on energy consumption and
far less people. Cutting down on energy consumption, while at the same time
the number of earthlings increase, provides nothing per balance. That is emptying
the ocean with a thimble.
|These are going to be interesting times |
Energy content and water example
The energy content of a battery
Voltage and the number of ampere-hours are always mentioned on a battery.
The energy-content can be calculated by multiplying the voltage (volts) with
the number of ampere-hours. The results is the amount of watt-hours which
can be stored in the battery.
Two examples:
|~ a battery of 24 volt and 15 ampere-hours has an |
|energy content of 24 × 15 = 360 watt-hours |
|~ a battery of 36 volt and 10 ampere-hours has an |
|energy content of 36 × 10 = 360 watt-hours |
So both batteries have the same energy content. Mentioning only the voltage
or the ampere-hours does not give any information about the energy content.
In shops where electric bicycles are sold one often talks about "a battery of
10 amperes". That doesn't indicate the energy content, as long as the voltage
and the time are not mentioned. There are even manufacturers of electric
bicycles who only mention the number of ampere-hours of the battery in their
leaflets and thus not the energy content.
Water Example
The water example is often used to make clear what the properties of
electricity are. Suppose the water pipe is capable of supplying (maximum)
10 litres of water per minute through a tap in a bucket.
Then the "power" of the water pipe is 10 litres of water per minute.
This power is also present when the tap is closed.
Power is a property.
As soon as the tap is fully open, every minute 10 litres of water is flowing into
the bucket. For example, after 5 minutes 50 litres of water have flowed from
the tap. Then the "energy" supplied is 50 litres of water
Energy always generates something, in this example it is water
Energy = power x time
The longer the tap is open, the more "energy" is flowing from it. If one closes
the tap, the "energy supply" stops but the power to provide energy remains.
There cannot be more water in the bucket, then its content permit. The shape
of the bucket is not important. A low bucket with a large diameter may contain
as much water as a high bucket with a small diameter. One can compare a battery
with the bucket. There can be no more energy in the battery than the energy
content permits. Which type is not important. A battery with a low voltage and
high ampere-hours can contain as much energy as a battery with a high voltage
and low ampere-hours.
Comparison of water – electricity
| |power |energy |
| water |litres per minute |litres |
| electricity |joules per second |joules |
Energy and labour
|~ Energy can be converted into labour |
|for example: electricity can make a motor run |
|~ Labour can be converted into energy |
|for example: a dynamo can generate electricity |
Suppose we make a trip by car and we return on the point of departure. The car
then has consumed a number of litres of petrol. The petrol contains energy.
(9,1 kilowatt-hours per litre). The efficiency of a petrol engine is about 25%.
That means that 25% of the energy in the petrol is converted into useful mechanical
labour. This propels the car during the trip. . Through the cooling of the engine and
the hot exhaust gases 75% of the energy disappears in the form of useless heat.
After the trip has been finished the useful mechanical labour is also fully converted
into heat. That heat arises from overcoming the air resistance, the friction in the
tires, the gearbox, the bearings, etc. After ending the trip all energy has be "bygone"
in the form of heat in space. The mechanical labour was an intermediate form.
Energy consumption of some household appliances
|appliance |power |use per day |energy per day |costs per day |
| LED-lamp | 5 watts |10 hours | 50 watt-hours |€ 0,01 |
| energy saving lamp | 15 watts |10 hours | 150 watt-hours |€ 0,03 |
| coffee machine | 750 watts |12 minutes | 150 watt-hours |€ 0,03 |
| water kettle | 2000 watts |6 minutes | 200 watt-hours |€ 0,04 |
| electric blanket | 25 watts |8 hours | 200 watt-hours |€ 0,04 |
| vacuum cleaner | 1500 watts |10 minutes | 250 watt-hours |€ 0,05 |
| ADSL-router | 12 watts |24 hours | 288 watt-hours |€ 0,06 |
| electric bicycle | 100 watts |3 hours | 300 watt-hours |€ 0,06 |
| flat screen TV | 100 watts |3 hours | 300 watt-hours |€ 0,06 |
| computer | 100 watts |4 hours | 400 watt-hours |€ 0,08 |
| steam iron | 1000 watts |30 minutes | 500 watt-hours |€ 0,10 |
| hidden consumption | 25 watts |24 hours | 600 watt-hours |€ 0,12 |
| incandescent lamp | 75 watts |10 hours | 750 watt-hours |€ 0,15 |
| refrigerator | 180 watts |5 hours | 900 watt-hours |€ 0,18 |
| washing machine | 1000 watts |1 hour | 1000 watt-hours |€ 0,20 |
| waterbed | 50 watts |24 hours | 1200 watt-hours |€ 0,24 |
| dryer | 2000 watts |90 minutes | 3000 watt-hours |€ 0,60 |
| 120 litre boiler | 3000 watts |90 minutes | 4500 watt-hours |€ 0,90 |
| air conditioner | 1000 watts |12 hours |12000 watt-hours |€ 2,40 |
1 kilowatt-hour costs € 0,20 (including energy tax, transport and VAT)
|~ Per day an ADSL-router consumes almost as much energy as needed |
|for the fully charging of an electric bicycle, or watching TV for 3 hours. |
|~ The refrigerator is enabled by the thermostat from time to time. |
|The "on" time is about 5 hours per day. |
|~ The power of 1000 watts for a washing machine is an average value. |
|The washing process can be divided into 3 phases with different energy |
|consumption: |
|1. heating the water, this will consume most energy |
|2. washing, the motor that rotates the washing consumes little energy |
|3. drying, the motor of the centrifuge consumes much energy |
|~ Per washing a dryer consumes 3 times as much energy as a washing |
|machine. |
|~ The boiler is usually warmed up at night. On average the desired |
|temperature of the water is reached again after 90 minutes. |
|(with 4,5 kilowatt-hours 50 litres of water is heated from |
|10 to 85 degrees Celsius). |
|~ A hidden consumption of 600 watt-hours per day will be a minimum |
|value for most households. That is about 6% of the total electricity |
|consumption. |
In the Netherlands the electricity consumption of a household is about
10 kilowatt-hours per day. At an energy price of 20 euro cents per
kilowatt-hour, that will cost € 2 per day = € 730 per year.
The continuous power of a household is 417 watts
The energy consumption (and also the "surreptitious consumption") of household
appliances can be measured very easily with a energy meter. This can be placed
between the wall socket and the device one wants to measure the energy
consumption of.
Anecdote
During a birthday party I entered into conversation with a middle-aged lady The
conversation soon went to trains and cars. "Did You come here by train?"
she asked with an expression of disbelief and horror on her face. When I said that
in the long term, we will run out of petrol, she suddenly became very aggressive.
Her reaction was: "but you cannot suppose that I will stop driving my car?"
(so even if the petrol has gone !!??)
The most horrible stories about public transport are always told by people who
never use it.
A book on energy
"Sustainable Energy without the hot air
This book gives a complete overview of the (im)possibilities of sustainable energy
Author: David MacKay, professor at the University of Cambridge. Read especially
chapter 19: "Every BIG helps"
Some quotes from the book:
|~ if everyone does a little, we'll achieve only a little |
|~ is the population of the earth six times too big? |
|~ any sane discussion of sustainable energy requires numbers |
This book also mentions an interview with Tony Blair (4 children!) in response to
his position in 2006 on the energy problematic
Tony Blair:
"Unless we act now, not in some distant time, but now these consequences,
disastrous as they are, will be irreversible. So there is nothing more serious,
more urgent or more demanding of leadership."
Interviewer:
Have you thought or perhaps not flying to Barbados for a holiday and not using
all those air miles?
Tony Blair:
I would, frankly, be reluctant to give up my holidays abroad
Interviewer:
It would send out a clear message though wouldn't it, if we didn't see that great
big air journey off to the sunshine? – a holiday closer to home?
Tony Blair:
Yeah – but I personally think these things are a bit impractical to actually
expect people to do that. I think that what we need to do is to look at how you
make air travel more energy efficient, how you develop the new fuels that will
allow us to burn less energy and emit less. How – for example – in the new frames
for the aircraft, they are far more energy efficient. I know everyone always – people
probably think the Prime Minister shouldn't go on holiday at all, but I think if
what we do in this area is set people unrealistic targets, you know if we say to
people we're going to cancel all the cheap air travel - You know, I'm still waiting
for the first politician who's actually running for office who's going to come out
and say it – and they're not.
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