Arizona Public Service works on interconnect for Ocotillo plant expansion

Filed May 25 at the Federal Energy Regulatory Commission by Arizona Public Service (APS) was an executed Engineering & Procurement Agreement (E&P) between APS Transmission and APS Fossil Project for a planned expansion of the gas-fired Ocotillo Power Plant.

APS Fossil Project is seeking to interconnect its facilities and network upgrades associated with the proposed 595-MW “large generation project” at the Ocotillo Power Plant with APS’s transmission system located in Tempe, Arizona. To obtain interconnection service for the project, it will be necessary to construct certain interconnection facilities.

Construction of such interconnection facilities will be governed by a Large Generator Interconnection Agreement (LGIA), which the parties anticipate executing at a later date. Prior to the execution of the LGIA, the parties have entered into the E&P agreement in order to initiate certain engineering and procurement activities that require long lead times.

In a related matter, APS told the U.S. Environmental Appeals Board in a May 12 brief that the board should deny the Sierra Club’s April 21 petition for review of the Maricopa County Air Quality Department’s (MCAQD) prevention of significant deterioration (PSD) permit authorizing APS to construct five new natural gas-fired combustion turbines at the Ocotillo Power Plant

Said the utility’s May 12 brief: “Sierra Club seeks to force MCAQD to conduct a more detailed analysis of whether battery storage of electricity should somehow be incorporated into the proposed source in order to reduce its greenhouse gas (‘GHG’) emissions.”

APS is the owner and operator of the Ocotillo Power Plant, located in Tempe. APS has been issued a permit to construct the Ocotillo Power Plant Modernization Project, in which APS plans to replace two steam electric generating units at the site with five new natural gas-fired simple-cycle combustion turbines of approximately 100 MW each.

The new turbines will serve to replace the 200 MW of peak generation that will be retired at Ocotillo, and will provide an additional 300 MW of peak generation to handle future growth. The project is designed to serve as a peak load facility that will quickly respond to rapid changes in electricity demand, particularly in response to fluctuation in generation from solar energy sources.

APS is a subsidiary of Pinnacle West Capital Corp. (NYSE: PNW).

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.