Coolidge Generating Station
Coolidge, Arizona, United States
Client: TransCanada Pipelines, Ltd
Parsons Brinckerhoff Role: Engineering Design, Construction Management
Parsons Brinckerhoff, in joint venture, provided detailed engineering services and construction support for the Coolidge Generation Station, which is a 512-megawatt simple cycle peaking power plant utilizing 12 combustion turbine generators with evaporative cooling power augmentation. The plant was designed for daily start/stop peaking operations and is able to operate continuously, if needed, consistent with permitted water supply availability. The plant is also capable of providing a utility operating reserve through rapid 10-minute startup capability.
The plant is capable of operation at ambient temperatures as high as 122 degrees Fahrenheit (50 degrees Celsius) with a majority of the operating time anticipated to occur at ambient temperatures above 100 degrees Fahrenheit (38 degrees Celsius). The plant is also capable of operation during extreme winter conditions as low as 15 degrees Fahrenheit (-9 degrees Celsius), employing anti-icing systems utilizing an electrically heated hot water closed-loop circulating system to heat the combustion turbine generators’ air intakes that have heating coils.
The combustion turbine generators utilize pipeline-quality natural gas as the fuel source. The site is connected to the Salt River Project 230-kV transmission system via the Salt River Project’s supplied local high-voltage switchyard. Water for the plant is supplied from new onsite wells; plant wastewater will be discharged to on-site lined evaporation ponds for disposal.
Coolidge was completed ahead of schedule and under budget, and went on line in May 2011.