Overview of Western Interconnect transmission line

Western Interconnect LLC (“WI”) is building a 35-mile, single circuit 345 kV AC merchant transmission line connecting Public Service Company of New Mexico’s (“PNM”) Blackwater substation to a new 345 kV switching station located northeast of Clovis in Curry County, New Mexico. The normal transfer capacity of the line will be 1,100 MW (1,157 MVA at a .95 power factor).

The WI transmission line is expected to begin commercial operations on January 1, 2017.

Western Interconnect LLC was formed by Tres Amigas LLC and Pattern Energy Group LP to develop, finance, construct, own and operate the WI transmission line.

FERC Negotiated Rate Authority for WI

On December 10, 2015, the U.S. Federal Energy Regulatory Commission (“FERC”) conditionally approved in docket ER15-2647 the request for negotiated rate authority for the WI project; WI’s compliance filing was subsequently accepted on February 9, 2016. This approval allows WI to conduct an Open Season and transmission capacity allocation process for all parties interested to subscribe for transmission capacity.

WI Existing Transmission Customers

On February 9, 2016, FERC accepted the Transmission Service Agreements (“TSA”) and Large Generator Interconnection agreements (“LGIA”) between WI and three wind projects totaling 497 MW. Below is a brief summary of these anchor customer agreements.

Transmission Customer Beginning Date of Service Term (years) Contract Capacity Contract Rate ($/MW-month)
Broadview Energy JN, LLC January 1, 2017 25 167 MW $2,292
Broadview Energy KW, LLC January 1, 2017 25 130 MW $2,292
Grady Wind Energy Center, LLC April 1, 2018 25 200 MW $2,292

Interconnection Agreement with PNM

WI has executed a Transmission Construction and Interconnection Agreement with PNM to interconnect up to 750 MW at the Blackwater substation. If total transmission service reservations on the WI from anchor customers and selected Open Season participants exceed 750 MW, WI will submit to PNM on behalf of its transmission customers a request to increase the interconnected capacity. Additional studies by PNM or eventual upgrades on their system to interconnect more than 750 MW may entail additional costs for prospective transmission customers of WI.