Thai/USA Renewable Energy Grid-Interconnection Study Tour



Thai/USA Renewable Energy Grid-Interconnection Study Tour

26 September – 2 October, 2004

Trip Report

Purpose: To bring together Thai and American electrical utility and government decision makers to learn from US technical, administrative, and regulatory experience with grid interconnection of small renewable energy systems.

Background: In April 2002 the Royal Thai Government approved regulations allowing grid interconnection and net metering of small scale (up to 1 MW) renewable energy generators. The United States has similar regulations in place in 39 states. A number of US utilities, government offices, and private companies have developed significant experience with these systems. This study tour allowed Thai decision-makers to gain confidence and learn from the US experience with net metering. The study tour was funded from a variety of sources, including US-AEP, EPPO, PEA, MEA and the DEDE.

Study tour overview: Traveling in Oregon and Washington, the delegation spoke with experts at six utilities that have implemented net metering, and one state energy office involved in net metering. The delegates familiarized themselves with interconnected renewable energy technologies including photovoltaics, micro-hydro, and biogas ranging from 25 kW to 3.6 MW; the functioning of utility programs for net metering including vendor training, application processing, and system inspection; and utility experiences with customer owned distributed generation. Net metering and streamlined grid interconnection policies have been popular in Oregon and Washington States, and utilities have on the whole have found it appropriate to develop a proactive approach that supports customer-owned renewable energy generation. Participants also saw other ways that utilities in the Pacific Northwest are integrating renewable energy into their practices. These include use of Integrated Resource Planning (IRP) to guide new resource acquisitions, Green Power programs (in which users pay extra for renewable energy), and utility decisions to purchase wind power simply because it is a cost-competitive, risk-reducing addition to their generation portfolios.

Portland General Electric (All day, Monday Sept 27, 04)

Main Contact: Bruce Barney Bruce_Barney@. Tel: (503) 464-7812

PGE is an investor-owned utility, with Enron as a major shareholder. The utility has 2,687 employees, and serves over 750,000 customers in 51 cities over 4,000 square miles (10,400 square km). PGE has been supportive of customer-owned grid-connected distributed generation – both renewable and non-renewable.

Customers may qualify for PGE’s Net Metering Service if:

▪ The customer owns the generation.

▪ The project is designed primarily to supply power for the customer’s home or small business.

▪ The generation is powered by wind, hydro, solar, or uses fuel cell technology.

▪ It generates no more than 25 kilowatts.

The customer’s generation operates in parallel with PGE’s existing distribution facilities. At no charge, PGE will install bi-directional metering equipment. The meter, composed of 2 uni-directional meters inside) records both the flow of power from PGE to the customer, and any power flow from the customer’s generator that leaves the site and goes to the electrical grid.

Net Metering customers are responsible for the basic charge as found on the current rate schedule, regardless of usage and usage charges. Currently, there are about 50 Net metering customers, 4 from micro-hydro and the remaining from solar. Total net metered generation is 265 kW.

In addition to net metering, PGE has programs for grid interconnection of larger generators. Grid-connected renewables up to 1 MW are compensated at the avoided cost, as determined by a rate schedule called “Schedule 201”. (This is essentially the same as Thailand’s “bulk supply tariff” which is the tariff used to compensate Thai VSPP customers for net excess geneation). Net metered customers are allowed to offset retail consumption with their own production just like VSPP in Thailand. Net excess generation is compensated at the schedule 201 rate. Net metering customers are eligible for personal state income tax credit of up to $1,500 per installation, as well as funds from the Oregon Energy Trust equal to $3.25 per installed peak watt (earlier it was $4.25 per installed peak watt). PGE refers to the IEEE Standard P1547 for interconnection requirements for DG. IEEE P1547 is applicable to DG up to 10 MVA in size (aggregate) at the PPC (Point of Common Coupling) and automatic transfer scheme (close transition)-longer than 100 ms.

Green Power

PGE operates a very active Green Power program in which customers volunteer to pay a premium for renewable energy. The green power product is promoted using bill inserts, radio and TV advertisements, internet, events at festivals, as well as tables in front of stores to direct market to customers. Currently 30,000 of PGE’s 750,000 customers have signed up. One package, 100% wind power for 20% of electricity usage, costs $3.25 per month. A “greener” package is for 100% of usage from renewables, which costs a premium of $8 to $10 per month. PGE is putting together a new Green Power program for businesses which will use wind power from a 200 MW wind farm in Eastern Oregon and will promise fixed retail price per kWh. The program relies of fixed wholesale prices for wind power that are less than 5% higher than the current price of combined cycle gas generation.

Dispatchable Standby Generation

PGE has an active program to meet peak demand using customer’s emergency generators, similar to the EGAT’s proposed “Peak Cut” program. The program came into existence as a way to reduce PGE’s exposure to price spikes in the spot market for electricity. These spikes rose as high as $3000 per MWh during the CA crisis. Running emergency generation makes sense if wholesale spot market prices rise above $80 or $90 per MWh. A total of 23 MW from 8 customers are currently part of the program.

In order to convince customers to join the program, PGE will pick up all maintenance and fuel expenses. The standby generators are always available to backup the customers’ facility and will operate synchronized and in parallel with PGE power so there is no service interruption.

For the privilege of running these generators when needed, PGE will:

• Upgrade switchgear and install control and communications hardware at no charge, increasing reliability and improving control of your system.

• Assume all maintenance and operation costs for the systems, eliminating the customers’ costs for fuel, repairs, tune-ups, oil changes, filter replacements and overhauls.

• Provide additional sound attenuation, if needed, quieting the generator system.

• Provide additional fuel storage, if needed, expanding operating time during those weather-related, long-term power outages.

• Test the systems at least once a month under full load; frequent full-load testing ensures the generator will operate successfully during an outage and is better for the engine.

To control the generators, PGE pays for and installs communication systems for each system so that PGE can control these generators remotely from PGE’s center office using software running on a PC. The generators can be dispatched either from the PGE main office, or from the PGE control room.

Earth Advantage National Center

Earth Advantage National Center opened in 2001, offering users a cutting-edge energy efficiency and sustainable design resource. The facility is designed to help architects, engineers, lighting and electrical contractors, builders and facility mangers design homes and buildings that use energy and resources wisely. In addition to a variety energy saving technologies, the facility includes a 5 kW grid-connected Proton Exchange Membrane (PEM) fuel cell powered with methanol fuel.

Crown Hill Farms (Morning, Tuesday Sept 28, 04)

Contact: Eugene & Juliette Gunderman, 503-472-5496. 18155 SW Baker Creek Rd. McMinneville, OR crownhillfarm@

Crow Hill Farms operates a 25 kW microhydro project using runoff water from 175 (442 rai) acres of land. An excellent overview of the project is available at:

Electricity feeds directly into the local cooperative utility, McMinneville Power and Water, which donated $5,500 worth of meters and transformer for the project. The project has two pelton turbines each powering a common shaft of a 25 kW induction generator. The turbine was built and installed by . Because the system is not a run-of-river project, the Federal US Fish and Wildlife department had concerns that higher temperature water entering the stream might disrupt breeding activity of fish. Temperatures may be higher than creekwater because the project uses runoff water held in holding ponds. (Though one could argue that if the project did not exist, runoff temperature would be about the same). Electronic temperature monitors shut off water flow if the water temperature from the holding ponds is a few degrees warmer than the water in the creek.

The control and protection system of the induction generator was remarkably simple. A tachometer senses induction generator shaft speed. When speed approaches 1800 rpm (consistent with 60 Hz electricity) a relay would connect the generator to the utility grid. There are no additional relays.

Because water supply is intermittent (normal operation is in during mid-Oct to mid-June), payback time based on engineering cost for the micro-hydro generator is about 18 years. However, because the project is eligible $22,750 in tax credits through the Oregon renewable energy tax credit (see Oregon Energy Office below), the payback period for the Gunderman family is somewhat lower.

A reporter and photographer from the McMinneville News Register covered the arrival of the Thai delegation. Their article is available at:



CalGon Farms (Afternoon, Tuesday Sept 28, 04)

CalGon farms in Polk County, Oregon, is a dairy farm currently with 350-500 head of cattle. PGE runs a 70 kW generator powered by methane produced from a completely stirred tank reactor (CSTR) fed with pumped manure from the cows. PGE estimates they can generate around 125 watts of electricity per cow. The reactor is mesophilic with an 8 to 10 day residence time. Manure enters a 28-foot high digester where it releases methane gas, which then fires a generator on the farm, feeding up to 70 kilowatts of renewable electricity directly to PGE customers. Leftover materials are processed through a solids separator into relatively odor-free fibers and liquids that can be used for commercial nursery or farm soil applications.

A heat exchanger from the liquid-cooled internal combustion generator is used to warm the digestor. Effluent quantity from the farm has decreased substantially. Whereas previously it was necessary to pump the farm’s lagoon more than twice a year, it is now necessary to pump only once a year. So far in 18682 run hours, the project has produced 599 MWh, implying average net generation of about 30 kW. The interconnection equipment was extensive, including typical IEEE 1547 relays and a radio link to PGE – presumably to their SCADA system.

The project started generating electricity in March 2002. The digestion and electricity generation system are owned by PGE. PGE hopes this system will eventually be cost-competitive with other renewable resources like wind turbines. Unfortunately, PGE found that the output from the system is less than expected.

Oregon National Guard (Afternoon, Tuesday Sept 28, 04)

In Salem, the Oregon National Guard headquarters operates two 800 kW (?) emergency generators. These power 911 telephone and state police communications as well as critical National Guard functions. The generators have joined PGEs dispatchable stand-by generator program. PGE invested $400,000 to interconnect the generators. Dispatching is accomplished using a dedicated 56k frame relay on a leased line. An internet video cam allows PGE to visually monitor the site.

Oregon Energy Office (Morning Wednesday Sept 29, 04)

Contact: Mr. Christopher Dymond. Christopher.S.Dymond@state.or.us; (503) 378-8325. 625 Marion St NE Salem OR

The Oregon energy office was established in 1975. Since 1980 they have run an income tax credit program and a loan program for energy efficiency and renewable energy. They also work on issues of nuclear safety and cleanup that affect Oregon citizens, including decommissioning of the Trojan reactor and coordinating with Washington state over cleanup of nuclear waste at Hanford Nuclear Reservation.

Income tax credit program

The income tax credit program is divided into business and individual tax credits.

Business tax credits

The business state tax credit provides up to 35 percent of project costs, taken over four years: ten percent for the first three years and 5 percent for the forth year. There is a tax credit cap of $35 million per project.

For businesses or individuals without high tax liability (businesses already showing a loss, etc.), the program allows the tax credit to be sold to another for-profit entity that can use the tax credit. The company that purchases the tax credit purchases them at the tax credit’s net present value – typically 25% of project cost.

Individual

The residential program is similar except that it incorporates a performance-based credit rather than a capital buy-down. Systems are tested and certified by the Oregon State Energy Office. By testing to insure that systems perform as advertised, The Oregon State Energy Office performs two important functions. First, this ensures that subsidy money is not wasted. Second, it provides customers with the confidence that they are purchasing a system that will perform as expected. For energy efficiency measures, the individual (one time) tax credit is equal to $0.40 per kWh multiplied by the total number of kWh in a year. For renewable energy (wind and solar) the amount is $0.60 per kWh.

Loan program

In the loan program, the Oregon State Energy Office sells government-guaranteed general obligation bonds and uses these to finance energy projects. This mechanism provides a very low risk investments for investors, and a loan with interest rates about 1% lower than commercial loans for borrowers.

Utility restructuring has had a significant impact on the programs. As part of utility restructuring in Oregon there was a Public Purpose Charge of three percent of gross revenues levied on utilities. In 2001 a special NGO was formed called the "Energy Trust" with the staff of 9 in a Board of Directors appointed by the Public Utilities Commission. The Energy Trust is authorized for ten years, providing a more stable business environment for energy efficiency companies. The Bonneville Power Administration has a similar program for public utilities. Municipal utilities can elect to be in the program or not.

Standards and Codes

Perhaps the most important steps that the Oregon Energy Office is to develop energy codes and standards for residences. These have led to an estimated savings of $500 million per year in energy in the state.

Seattle City Light, Snohomish Public Utility District, Puget Sound Energy (Thursday 30, 2004)

The delegation met with representatives from Seattle City Light (SCL), Snohomish Public Utility District (SnoPUD), and Puget Sound Energy (PSE). Each has a net metering program, and has a variety of grid-interconnected renewable energy projects.

Main contacts:

SCL: David Van Holde. david.vanholde@ 206-684-3954

SnoPUD: Chris Fate. CDFate@

Seattle City Light (SCL) is a municipal utility owned by the City of Seattle. Founded in 1902, SCL provides electric power to the City of Seattle and neighboring suburbs. 90% of total generation comes from hydro, but the utility (under directions from the Seattle City Council) has committed that all future load growth will be met by non-hydro renewable energy or by energy conservation. The utility is on-target to meet this goal, and has several decades of experience that document that for the utility, saving electricity is less expensive than investing in new generating capacity. The utility makes wide use of Integrated Resource Planning (IRP) to meet new demand. With IRP, the cost of new supply is compared with the cost (per kWh) of energy conservation and renewables. The utility is obligated to chose the least cost option. The utility’s load growth is 1-2% per year, currently with 1100 MW average load, with peaks of around 2000 MW. SCL’s net metering program is advertised through their website at: . Besides net metering, the SCL has larger grid-connected renewable energy installations which the delegation visited during the course of the day.

The Snohomish PUD is a publicly owned utility district serving rural areas north of Seattle. With 825 employees, it serves over 290,000 customers in a service area spanning 2,200 square miles. Fuel mix is 83% hydro, with 9% nuclear and 6% coal. SnoPUD’s net metering program is advertised through its website at:

Puget Sound Energy is an investor owned utility, serving nearly 1 million electric customers. The utility offers net metering for customers up to 50kW, and has expanded this on a case by case basis to larger customers. Net metering program details are available at:

David Von Holde from SCL generously arranged for us to visit several grid-connected renewable energy generators in the vicinity, including a 1 MW fuel cell at the King County Renton South Treatment Plant, and a 3 x 1.3 MW recripocating engine generator facility at King County West Point Sewage Treatment Plant.

King County Renton South Treatment Plant

King County Renton STP treats wastewater for about 1.4 million people in the Puget Sound Region. Everyday STP treats about 75 million gallons of wastewater from homes businesses and industries around the area. In the process of wastewater treatment, sufficient biogas is produced to generate about 4 MW of electricity. The biogas produced is 60 to 64% CH4.

The world’s largest demonstration project of a single unit fuel cell power plant produces up to 1 MW of electricity primarily powered by biogas produced from the STP. The molten carbonate fuel cell operates at 900 degrees F (482 degrees C), and was installed at a cost of $12 million. Since around Oct 2003, the fuel cell system has worked properly. The system is designed to work 5 years at 55 to 60% efficiency. The system uses a solid-state inverter for interconnection with the grid, and electricity offsets electricity purchased from Puget Sound Energy.

King County West Point Treatment Plant

King County West Point Treatment Plant treats 440 million gallons (1665 million liters) a day wastewater from households and storm runoff. The plant includes biogas digestors that produce biogas used to ppower seven mechanically driven 2,000 horsepower pumps, as well as three 1.3 MW generators. In the future, the facility plans to expand to two 2.5 MW generators. Synchronization of the (synchronous) generators with the Seattle City Light grid is accomplished manually. Grid interconnect breakers are installed on the low voltage side of the MV transformer.

The extensive use of biogas at sewage treatment plants in the Seattle area suggests that the same might be possible for making electricity through biogas from anaerobic treatment of sewage waste in Bangkok.

Orcas Power and Light (OPALCO) (Friday Oct 1, 2004)

Main contact: Martha Warachowski: MWarachowski@;

Orcas Power & Light Cooperative (OPALCO) provides electricity to twenty islands in San Juan County. 85% of total transmission and distribution wire is underground cable. Electricity is transmitted to the utility and to different islands through 69 kV undersea cables that cost about $250/foot installed. Almost electrical power is imported from the mainland at the buying rate of 2.5 cents/kwh, and the retail rate for customers is about 6 cents/kWh.

Net metering program

OPALCO’s net metering program is open to generators up to 25 kW, though exceptions are made on a case by case basis. The utility has 20 net metering accounts, generating 113,000 kWh per year. The utility has a strong incentive program to support local renewable energy. Solar is eligible for a $1.50 per watt subsidy. All renewable energy technologies are eligible for a subsidy of $1.50 per kWh for the first year. Maximum system subsidy is $4,500.

Green Energy Program

OPALCO’s green energy program is prominently advertised on the home page of its website. Customers can contribute to green energy by paying additional price. Subscribers to Green Energy Program can purchase OPALCO Green Power for $3.50 per 100 kilowatt-hour (kWh) blocks, or select the All Green option for a 3.5 cents per kWh premium. Both pricing options would be in addition to regular kWh charges from OPALCO. There is no limit to the amount of green power can purchased. Up to now, there are 13,000 subscribers, about 5% of total customers.

Blakely Island micro-hydro

OPALCO representatives joined the Thai delegation on a chartered boat trip to Blakely island where Seattle Pacific University operates a 25 kW microhydro that has been interconnected with the grid for over 10 years. The micro-hydro is powered by water that drains from two lakes on the island.

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