Arizona Public Service files interconnect for expanded Ocotillo gas plant

Arizona Public Service Co. filed Nov. 9 with FERC a Large Generator Interconnection Agreement between APS Transmission and APS Fossil for an addition to the Ocotillo power plant.

This agreement covers construction of the facilities needed to interconnect a 595-MW combustion turbine generation facility to the APS Transmission System at the Ocotillo Substation. The project will physically connect four of the five combustion turbine units to the Ocotillo 230-kV bus through two 230-kV generator interconnection tie lines. The fifth combustion turbine unit will interconnect to the Ocotillo 69-kV bus through a 69-kV interconnection tie line. The Point of Interconnection (POI) for this project will therefore be at both the Ocotillo 230-kV and 69-kV busses within the Ocotillo Substation.

Arizona Public Service Co.’s Ocotillo Modernization Project is due for commercial operation under this agreement on Oct. 31, 2018.

In prior developments for this project:

  • The Environmental Appeals Board at the U.S. Environmental Protection Agency on Sept. 1 rejected a Sierra Club petition for review of a Clean Air Act prevention of significant deterioration permit that the Maricopa County Air Quality Department issued to Arizona Public Service in March 2016. The permit authorizes Arizona Public Service to construct five new natural gas-fired combustion turbines at its Ocotillo Power Plant in Tempe, Ariz.
  • Arizona Public Service on June 1 asked the Arizona Corporation Commission for the first comprehensive review of the company’s rates in five years, with the rate hike needed in part to build this expansion of the gas-fired Ocotillo plant.
  • Said the Aug. 2 quarterly Form 10-Q report of APS parent Pinnacle West Capital Corp. (NYSE: PNW) about this project: "APS has six natural gas power plants located throughout Arizona, including Ocotillo. Ocotillo is a 330 MW 4-unit gas plant located in the metropolitan Phoenix area. In early 2014, APS announced a project to modernize the plant, which involves retiring two older 110 MW steam units, adding five 102 MW combustion turbines and maintaining two existing 55 MW combustion turbines. In total, this increases the capacity of the site by 290 MW, to 620 MW, with completion targeted by summer 2019."
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.