Determination of Available Transfer Capability (ATC)



Determination of Available Transfer Capability (ATC)

For

Texas - New Mexico Power Company (TNMP)

(Version 3)

Mountain Region Engineering

Keith Nix, Managing Engineer

Texas - New Mexico Power Company

May 8, 2002

I. Introduction - In accordance with the recent Federal Energy Regulatory Commission (FERC) Order No. 888 and 889, Available Transfer Capability (ATC) must be calculated for electric utilities’ interconnected transmission systems. Although a universal methodology has not been developed for the entire industry, with reference to the North American Electric Reliability Council’s (NERC) paper entitled, “Available Transfer Capability Definitions and Determination” ATC is to be defined as:

Available Transfer Capability (ATC) – The measure of the transfer capability remaining in the physical transmission network for further commercial activity, over and above already committed uses.

The reasoning behind the development of ATC is based on several principles developed by NERC. ATC must produce viable results. In short, the ATC developed by transmission-owning entities must give a viable and reliable method for which other market participants can utilize any available transfer capability. Incorporated in this, transmission owners must develop an ATC calculation strategy that allows for reasonable uncertainties in system conditions and affords reserve capacity to address emergency situations. ATC must recognize time-variant power flow conditions and the effects of simultaneous transfers/parallel path flow from a reliability viewpoint. The electric utilities’ ATC strategy must include flexibility in allowing for different transfer capabilities over time and reasonably capture these capabilities in a time variant posting. ATC calculations must be dependent on the points of electric power injection, the directions of transfers across the network and the points of delivery. For the TNMP system, there are only a few transfer paths where any type of injection/power delivery from other market participants can take place. TNMP’s ATC strategy must accurately incorporate these points into a concise and consistent method for presentation.

The TTC and ATC values ,which are posted on TNMP’s OASIS site, are values for the available TNMP transmission paths with all transmission lines in service. However, during contingencies or times when transmission in Southern New Mexico is scheduled out of service, these values may change. TNMP will make every effort to notify market participants via OASIS or other methods of contingencies or curtailments that affect ATC/TTC calculations.

II. Definitions - The following definitions that will be used in this document are derived from the following sources:

1) FERC Order No. 889

2) Available Transfer Capability Definitions and Determination (NERC)

3) Determination of Available Transfer Capability Within the Western Interconnection (WECC)

Total Transfer Capability (TTC) (2) - The amount of power that can be transferred over the interconnected transmission network in a reliable manner while meeting a specific set of pre-and post-contingency system conditions. This capacity is defined by the worst contingency for the defined point-to-point path and the thermal, voltage and/or stability limits of the path. The TTC calculation must conform with WECC’s “Procedures for Regional Planning Project Review and Rating Transmission Facilities” and WECC’s Reliability Criteria. If a transmission path does not have a WECC Accepted Rating, that path must still conform to the rating methods defined in those documents.

Available Transfer Capability (ATC) (2) – A measure of the transfer capability remaining in the physical transmission network for further commercial activity over and above already committed uses. Mathematically, ATC is defined as:

ATC = TTC – TRM – CBM - existing transmission commitments

Transmission Reliability Margin (TRM) (2), (3) - The amount of transmission transfer capability needed to ensure that the interconnected transmission network is secure under a reasonable range of uncertainties in system conditions. These uncertainties may result from the following:

1. Simultaneous limitations with a parallel path

2. Reservations for unscheduled flow, i.e., loop flow

3. Reservations for unplanned transmission outages, i.e., for paths in which contingencies have not already bee included in the calculation of TTC

TRM does not include reservations for planned outages and other known transmission conditions which have been included in the calculation of TTC.

Capacity Benefit Margin (CBM) (2), (3) - The amount of transmission transfer capability reserved by load serving entities to ensure access to generation from interconnected systems to meet generation reliability requirements. These reservations may include the following:

1. Transmission reserved by the Control Area Operator to accommodate operating reserves (spinning and supplemental). Such operating reserves may not exceed NERC and WECC applicable pool requirements or individual members’ reliability requirements.

2. Transmission reserved for the import of ancillary services (such as spinning reserves) from another control area.

3. Transmission reserved for generation patterns and generation contingencies. These patterns and contingencies must be based upon reasonable, publicly available assumptions subject to evaluation in applicable dispute resolution proceedings.

Note: CBM may be sold on a recallable basis.

Curtailability (2) - The right of a transmission provider to interrupt all or part of a transmission service due to constraints that reduce the capability of the transmission network to provide that transmission service. Transmission service is to be curtailed only in cases where system reliability is threatened or emergency conditions exist.

Recallability (2) - The right of a transmission provider to interrupt all or part of a transmission service for any reason, including economic, that is consistent with FERC policy and the transmission provider’s transmission service tariffs or contract provisions.

Non – Recallability (2) - Transmission service that only be interrupted in cases where system reliability is threatened or an emergency exists.

Recallable ATC (RATC) (2) – Defined as TTC less TRM, less recallable transmission service, less non-recallable transmission service (including CBM).

Non – Recallable ATC (NATC) (2) - Defined as TTC less TRM, less non-recallable reserved transmission service (including CBM).

Note: Transmission service must adhere to a standard set of priorities to avoid confusion. These priorities are:

1. Non-recallable service has priority over recallable service

2. Recallable transfers, both reserved and scheduled, may be recalled for non-recallable transfer requests

III. Posting Schedules for Available Paths – FERC Order No. 888 and 889 require the posting of two types of paths: “constrained” and “unconstrained”. The definition of a constrained path is as follows:

Constrained Path – A transmission path on which ATC has been less than or equal to 25 percent of the TTC for that path for at least one of the last 168 hours (7 days), or is calculated to be 25 percent or less of its posted TTC during the next 7 days.

According to the FERC Orders, ATC and TTC for constrained paths must be posted on the OASIS for the next 168 hours and, thereafter, daily to the end of a 30 day period. Both recallable and non-recallable service must be posted in this way. Additionally, ATC and TTC for constrained paths for non-recallable and recallable service must be posted on the OASIS for the current month and the next twelve months. However, the monthly posting for recallable service on constrained paths must be posted only if requested by a customer.

An unconstrained path is defined as any path posted on the OASIS that is not a constrained path. For posted unconstrained paths, the ATC and TTC for non-recallable and recallable transmission service are posted for the next 7 days, the current month, and the next 12 months. The posting for unconstrained paths must be updated when ATC changes by more that 20 percent of the path’s TTC.

The FERC Orders do not require any ATC and/or TTC postings be made for any path more than 13 months in advance except if planning and specifically requested transmission studies for that path have been performed. If this has occurred, then capability must be posted for the year following the current year and for each year following to the end of the planning horizon, but not to exceed 10 years.

The following summary lists the posting requirements for transmission paths to be listed on the OASIS:

Constrained Paths:

|Service |Total Transfer Capability |Available Transfer Capability |

|Non-recallable |Each hour for next 7 days |Each hour for next 7 days |

| |Each day for next 30 days |Each day for next 30 days |

| |Each month for next 12 months |Each month for next 12 months |

|Recallable |Same as above |Each hour for next 7 days |

| | |Each day for next 30 days |

| | |Each month for next 12 months (see note) |

Note: Required only if requested by customer

Unconstrained Paths

|Service |Total Transfer Capability |Available Transfer Capability |

|Non-recallable |Each day for next 7 days |Each day for next 7 days |

| |Each month for next 12 months |Each month for next 12 months |

|Recallable |Same as above |Each day for next 7 days |

| | |Each month for next 12 months |

TTC and ATC values posted on TNMP’s OASIS site are calculated with all transmission lines in service. Therefore, TNMP’s values will change depending on certain transmission line outages in Southern NM.

III. Posted Transmission Paths – FERC Order No. 889 outlines the three conditions for which a transfer path is required to be posted on OASIS. These paths are called “posted paths” and are defined as follows:

1. Any path (segment) between two control areas

2. Any path for which transmission service has been denied, curtailed, or subject to interruption during any hour or part of an hour for a total of 24 hours in the last 12 months. In counting up to 24 hours, any part of an hour counts for a whole hour.

3. Any path on which a customer requests that ATC and TTC be posted. Customer requested postings can be dropped if no customer has taken service on the path in the last 180 days.

For TNMP’s system, “posted paths” on the OASIS are defined as point-to-point segments. TNMP generally only owns small transmission segments. In order for their usage, transmission usage arrangements with adjacent transmission owners must be secured before usage of the TNMP transmission segments may occur.

TNMP has a single category for its transmission classification. This category includes the posted TNMP paths between PNM’s Control Area with other Control Areas. It must be noted that in some cases, TNMP does not own transmission rights across the control area boundary. In that case, TNMP’s posted ATC and TTC will be zero. Additionally, the direction of the transmission rights will be indicated as either uni-directional (U) or bi-directional (B). The following is a list of TNMP’s posted transmission paths:

Paths Between Control Areas

Point of Delivery Point of Receipt Control Area Direction

Greenlee 345 KV Hidalgo 345 KV TEP B

Hidalgo 345 KV Luna 345 KV EPE B

Eddy Co. 345 KV Amrad 345 KV EPE B

Amrad 115 KV Alamogordo 115 KV EPE U

Picacho 115 KV Mimbres 115 KV EPE B

Once again, the TTC and ATC values that are posted on TNMP’s OASIS site are values for the TNMP transmission system with all transmission lines in service. However, during contingencies or during times when transmission lines are out of service for maintenance, these values might change depending on the outage.

Please refer to Appendix A for a geographical representation of TNMP’s transmission ownership and rights.

III. Guidelines for the Determination of TTC and ATC for TNMP’s Posted Transmission Paths - As stated earlier in this document, the procedures and methodology for the calculation of TNMP’s TTC and ATC values have been derived from the NERC document “Available Transfer Capability Definitions and Determination” and the WECC paper “Determination of Available Transfer Capability in the Western Interconnection”. These documents have given TNMP several options in the final determination of ATC and what should be posted on OASIS. The first important factor in determining TTC and ATC relates to Transmission Reliability Margin (TRM). TNMP does not own any generation in the Western Interconnection. Therefore, TNMP is totally dependent on the transmission system remaining intact to provide both recallable and non-recallable service to its customers. TNMP applies a constant TRM factor across its entire transmission rights in order to reserve transmission capacity in response to unplanned outages of the transmission system. Currently, this factor stands at 2% of TTC.

The second important factor relating to TNMP’s calculation of TTC and ATC is Capacity Benefit Margin (CBM). As defined, CBM is used to reserve part of the transmission system for generation reserves and the changes in the system usage due to changing generation patterns, generation contingencies, and system load growth. Once again, TNMP does not own any generation in the Western Interconnection. Therefore, TNMP will use the definition of CBM relating to various hazards concerning loss of resources. TNMP’s largest resource hazard is the unavailability of the Eddy Co. DC interconnection, amounting in 66 MW’s of lost transmission access to generation resources. Therefore, TNMP will claim a total of 66 MW’s of CBM on the Greenlee – Hidalgo 345 KV path on its transmission resources to account for this loss. In addition, TNMP transmission will need to be reserved for CBM relating to the loss of the Greenlee – Hidalgo 345 KV path on all other TNMP’s transmission paths.

TNMP’s methodology will also include provisions that include native load and contractual reservations in the determination of TTC and ATC values for TNMP’s transmission sections.

IV. Determination of TTC and ATC for TNMP Interconnection Segments – The TTC and ATC calculations for the TNMP segments are the amount of power that can be reliably transferred over the interconnection, i.e., the Point of Receipt is on the external control area boundary and the Point of Delivery is on the PNM control area boundary, or vice versa. From those interconnection points, the power is then delivered to load entities or passed on through other transmission providers systems for which rights must be purchased separate from the TNMP transmission sysetm.

TNMP has reserved on its primary interconnection paths sufficient transmission capability to import all of its contractual power supply to serve both native and other customer load. In addition, sufficient transmission capacity will also be reserved in the form of CBM to account for loss of resources.

The following is TNMP’s determination of TTC and ATC for its transmission system:

1. Greenlee 345 – Hidalgo 345 KV – The Greenlee 345 – Hidalgo 345 KV interconnection segment allows TNMP to utilize the 110 MW’s of ownership rights granted under the Southwest New Mexico Transmission project (SWNMT). This amount was determined through nomogram equations that were derived by El Paso Electric (EPE) as controlling agent for SWNMT. The nomograms specify the voltage and system stability parameters for which power can be reliably transferred from the Western Interconnection (see EPE document Principles, Practices, and Methods for the Determination of Available Transmission Capacity for El Paso Electric Company (EPE), Version 1.2.3 for listing of nomogram equations, available at ). The natural direction of power flow into the system on this transmission path is from Greenlee to Hidalgo.

The TTC and ATC for this segment are limited by several constraints: 1) native load requirements of 45 MW’s; 2) contractual agreements with a large industrial customer for transmission rights (65 MW’s); 3) TNMP system TRM (2% * 110 = 2MW’s); and 4) CBM for loss of Eddy Co. DC tie (66 MW’s). Therefore, the determination of TNMP’s TTC and ATC for this interconnection path is as follows:

TTC = 110 MW’s (TNMP’s full entitlement under SWNMT)

ATC = 110 MW’s – 45 MW’s – 2 MW’s – 66 MW’s = 0 MW’s

Hidalgo 345 – Greenlee 345 KV – As stated above, TNMP’s allowable transmission rights along this transmission path according to the SWNMT agreement is 150 MW’s. Once again, power flow along this path is naturally from Greenlee to Hidalgo. Therefore, the determination of TNMP’s TTC and ATC for this interconnection path is as follows:

TTC = 150 MW’s (TNMP’s full entitlement under SWNMT)

ATC = 150 MW’s – 0 – 0 – 0 = 150 MW’s

Note: For both of these transmission paths transmission service must be secured from other transmission providers before TNMP’s path may be utilized.

2. Eddy Co. 345 – Amrad 345 KV – TNMP has 1/3rd ownership in the DC converter station at Eddy Co. substation which allows interchange through Southwestern Public Service (SPS). The rating on the DC converter limits the TTC that TNMP will have available at any one time. At the present time, the converter rating is accepted to be 200 MW’s. Therefore, TNMP’s allowable capacity will be 66 MW’s. The normal direction of power flow on this path is from Eddy Co. to Amrad.

Once again, this path has certain constraints that limit the TTC and ATC calculations. These constraints include: 1) native load of 35 MW’s; 2) contract with SPS of 10 MW’s; 3) TNMP system TRM (2% * 66 = 1 MW); and 4) CBM for loss of the Greenlee 345 – Hidalgo 345 KV path. Therefore, the determination of TNMP’s TTC and ATC for this interconnection path is as follows:

TTC = 66 MW’s (TNMP’s full entitlement through contract w/EPE)

ATC = 66 MW’s – 35 MW’s – 10 MW’s – 1 MW – 20 MW’s = 0 MW’s

Note: TNMP’s CBM for this path will be made available on a non-firm basis upon request, consistent with current FERC policy.

Amrad 345 – Eddy Co. 345 KV – As stated above, TNMP’s allowable transmission rights according to its ownership in the DC converter station is 66 MW’s. Once again, the normal direction of power transfer along this path is from Amrad 345 to Eddy Co. 345 KV. Therefore, the determination of TTC and ATC for interconnection path is as follows:

TTC = 66 MW’s

ATC = 66 MW’s – 0 – 0 –0 = 66 MW’s

3. Hidalgo 345 – Luna 345 KV – The Hidalgo 345 - Luna 345 KV interconnection segment allows TNMP to utilize ownership rights granted under the Southwest New Mexico Transmission project (SWNMT). This contract results in transmission rights for TNMP’s usage of 25 MW’s.

This transmission path also has constraints that limit the amount of ATC available on this path. These constraints are as follows: 1) Scheduled delivery for native load usage; 2) TNMP system TRM (2% * 25 MW’s = 1 MW); and 3) CBM for the loss of the Eddy Co. DC interconnection (25 MW’s). Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 25 MW’s

ATC = 25 MW’s – scheduled native – 1 MW – 25 MW = 0

Luna 345 – Hidalgo 345 KV – The Luna 345 - Hidalgo 345 KV interconnection segment allows TNMP to utilize ownership rights granted under the Southwest New Mexico Transmission project (SWNMT). This contract results in transmission rights for TNMP’s usage of 25 MW’s.

This transmission path also has constraints that limit the amount of ATC available on this path. These constraints are as follows: 1) Scheduled delivery for native load usage; 2) TNMP system TRM (2% * 25 MW’s = 1 MW); and 3) CBM for the loss of the Greenlee 345 – Hidalgo 345 interconnection (25 MW’s). Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 25 MW’s

ATC = 25 MW’s – scheduled native – 1 MW – 25 MW = 0

4. Picacho 115 – Mimbres 115 KV – The Picacho 115 – Mimbres 115 KV interconnection path allows TNMP to utilize transmission rights acquired through a joint venture with PNM on the construction of the 115 KV line interconnecting Picacho Substation to Mimbres Substation. TNMP’s allowable transmission rights on this interconnection path by contract with PNM is 24 MW’s (ref. Agreement for the Construction and Operation of a 115 KV Transmission Line from Deming to Las Cruces NM Between Community Public Service Co. (TNMP) and Public Service Co. of New Mexico (PNM), dated June 18, 1968).

This transmission path also has constraints that limit the amount of ATC available on this path. These constraints are as follows: 1) scheduled delivery for native load usage; 2) Contractual agreements with El Paso Electric Co. for service to Airport Substation (8 MW’s); 3) TNMP system TRM (2% * 24 = 1 MW); 4) CBM for the loss of the Greenlee 345 – Hidalgo 345 KV interconnection path (14 MW’s). Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 24 MW’s

ATC = 24 MW’s – scheduled native – 8 MW’s - 1 MW – 14 MW = 0

Mimbres - Picacho 115 KV – The Mimbres - Picacho 115 KV interconnection path allows TNMP to utilize transmission rights acquired through a joint venture with PNM on the construction of the 115 KV line interconnecting Picacho Substation to Mimbres Substation. TNMP’s allowable transmission rights on this interconnection path by contract with PNM is 24 MW’s (ref. Agreement for the Construction and Operation of a 115 KV Transmission Line from Deming to Las Cruces NM Between Community Public Service Co. (TNMP) and Public Service Co. of New Mexico (PNM), dated June 18, 1968).

This transmission path also has constraints that limit the amount of ATC available on this path. These constraints are as follows: 1) scheduled delivery for native load usage; 2) Contractual agreements with El Paso Electric Co. for service to Airport Substation (10 MW’s); 3) TNMP system TRM (2% * 24 = 1 MW); 4) CBM for the loss of the Greenlee 345 – Hidalgo 345 KV interconnection path (14 MW’s). Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 24 MW’s

ATC = 24 MW’s – scheduled native – 8 MW’s - 1 MW – 14 MW = 0

5. Amrad 115 – Alamogordo 115 KV – The Amrad 115 – Alamogordo 115 KV transmission path allows TNMP to serve native load in Eastern New Mexico. TNMP is the sole owner of this transmission path. This path is listed as a radial feed into Alamogordo Substation because the prevailing flow is always unidirectional (flow occurs from Amrad to Alamogordo only).

Because TNMP is the sole owner of this line, the only constraint is the thermal limit of the transmission line itself. Currently, this transmission line is rated at 73 MW’s of capacity. Once again, the only scheduled flow that takes place over this line is delivery to TNMP’s native load customers. The additional component will be TNMP’s system reservation for TRM. Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 73 MW’s

ATC = 73 MW’s – scheduled native – 1 MW (TRM) = ?? MW’s

6. Lordsburg 115 – Hidalgo 115 KV – The Lordsburg 115 – Hidalgo 115 KV transmission path allows generation in the Lordsburg area to be interconnected to TNMP’s internal 115 kV system. TNMP is the sole owner of this transmission path. This path is listed as a feed into the Hidalgo 115 kV Substation where energy from Lordsburg can either be made available to market or scheduled to serve TNMP load.

Because TNMP is the sole owner of this line, the only constraint is the thermal limit of the transmission line itself. Currently, this transmission line is rated at 153 MW’s of capacity. The additional component will be TNMP’s system reservation for TRM (2%). Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 153 MW’s

ATC = 153 MW’s – 3 MW (TRM) = 150 MW’s

7. Lordsburg 115 kV – Hidalgo 345 KV – The Lordsburg 115 – Hidalgo 345 KV transmission path allows generation in the Lordsburg area to be interconnected to the bulk 345 kV system across TNMP’s 115 kV Hidalgo Substation bus. TNMP is the sole owner of the transmission path up to the 345 kV bus. This path is listed as a feed into the Hidalgo 345 kV Substation where energy from Lordsburg can be made available for market purchase.

Because TNMP is the sole owner of this line, the only constraint is the transformation limit of the two 345/115 kV transformers located at Hidalgo. The transformers are currently operated in parallel and provide up to 420 MVA of capacity. However, the limiting factor on this path will be the transmission line capacity on the Hidalgo – Lordsburg 115 kV transmission line. The additional component will be TNMP’s system reservation for TRM (2%). Therefore, the determination of TTC and ATC for this interconnection path is as follows:

TTC = 153 MW’s

0. ATC = 153 MW’s – 3 MW (TRM) = 150 MW’s

Note: Under conditions when a single 345/115 kV transformer is out of service, this path will be de-rated accordingly in a pro-rata share of the transmission requests for service across the Hidalgo 115 kV bus to the Hidalgo 345 kV bus.

0.

0. Lordsburg 115 kV – Greenlee 345 KV – The Lordsburg 115 – Greenlee 345 KV transmission path allows generation in the Lordsburg area to be interconnected to the bulk 345 kV system across TNMP’s 115 kV Hidalgo Substation bus and be moved to the eastern side of the Greenlee 345 kV bus.

0. As detailed above in the Hidalgo – Greenle 345 kV path description, TNMP is a joint owner of capacity on this path as per the SWNMT agreement. Therefore, this path capacity will be determined through TNMP’s ownership rights on this transmission segment. No TRM factor will be assigned to this path due to the fact that this is counter to the prevailing flow. Therefore, the determination of TTC and ATC for this path is as follows:

0.

0.

0. TTC = 150 MW’s

0.

0. ATC = 150 MW’s - 0 (TRM) = 150 MW’s

0.

0. Note #1: Under conditions when a single 345/115 kV transformer is out of service, this path will be de-rated accordingly in a pro-rata share of the transmission requests for service across the Hidalgo 115 kV bus to the Hidalgo 345 kV bus.

0.

0. Note #2: A pre-existing service request has been received by TNMP dated for March, 2003 which will limit this path when this request comes active. ATC values will be changed accordingly at that time.

0.

0. Lordsburg 115 kV – Luna 345 KV – The Lordsburg 115 – Luna 345 KV transmission path allows generation in the Lordsburg area to be interconnected to the bulk 345 kV system across TNMP’s 115 kV Hidalgo Substation bus and be moved to the Luna 345 kV bus.

As detailed above in the Hidalgo 345 kV– Luna 345 kV path description, TNMP is a joint owner of capacity on this path as per the SWNMT agreement. Therefore, this path capacity will be determined through TNMP’s ownership rights on this transmission segment. Additionally, TNMP is posting 0 ATC for this path in order to properly reserve capacity for native load. Therefore, the TTC and ATC for this path is as follows:

TTC = 25 MW’s

ATC = 25 MW’s – scheduled native – 1 MW – 25 MW = 0

. Conclusions – It is TNMP’s intention to fully comply with all commission rules and regulations with regard to posting TNMP’s available TTC and ATC on OASIS. TNMP realizes this is an on-going process that will need refinement from time to time. Therefore, as industry changes and new commission rulings warrant, TNMP will audit its calculation methods for changes that will keep TNMP current with industry standards.

Appendix A - Southern NM Transmission System

-----------------------

(Max 43 MW) 1

Springerville

1 PGT Interconnect (Schedule G - Expires 2020 )

(Reciprocated because TNP gives 30 MW of Hidalgo’s 115 kV

Transformer & diplaces Mimbres to Hidalgo displacement of 23.5 MW)

2 EPE Interconnect (Schedule C - Expires 2010) ($2/MWh)

66 MW less TNP’s Eastern Load

3 EPE Interconnect (Schedule C - Expires 2010) ($1/MWh)

TNP’s Eastern Load

G:\Resource\Price\Nmreg.ppt

100 MW (TNP/PNM)

PNM /

TNP

24 MW(TNP/PNM)

Ownership

(TNP 100%)

(73 MW)

(Max 23 MW) 1

(TNP 110 MW)

Ownership

Non Firm EPE Wheel3

Firm EPE Wheel2

200 MVA Transformer

West

Mesa

Belen

Eddy Co.

AC/DC Tie

Las

Cruces

TNP (25 MW)

Ownership

Hidalgo

Greenlee

Central

(MD-1)

Dona Ana

(PGT)

Amrad

66 MW Line Limit

73 MW Conv Limit

(TNP Owns 1/3 of

Line)

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