Cholla Power Plant, Arizona

The 767MW Cholla Power Plant, located in northeastern Arizona near Holbrook, burns coal from the McKinley Mine in New Mexico. Operated by APS (Arizona Power Service), which also operates the approximately 4,000MW Palo Verde nuclear plant, the 1,540 MW Four Corners coal plant, and a few other smaller coal and gas power plants in the state. One of the four units at the Cholla plant is operated by PacifiCorp, which, along with the other units at this plant, supplies power to the Pacific Northwest from the APS system in the winter, when electricity demands are higher in the Pacific Northwest (due to heating needs), and lower in the Southwest. In the summer, when Arizona's electrical demands are higher (due to air-conditioning), and lower in the Pacific Northwest, the exchange is reversed. In 2016, APS closed Cholla Unit 2, in the hope of meeting new EPA emission standards. APS has subsequently announced that it intends to close Units 1 & 3 roughly by 2025, unless converting them to natural gas proves a viable option.