Water use is one of many factors TEP considers when evaluating energy resources. Nuclear power plants use water for cooling, for example, while fossil-fueled plants drive turbines with steam created by heating water in large boilers. Some solar thermal plants work in a similar way, making them a much more water-intensive choice than solar photovoltaic arrays.
Because water supplies are limited by Arizona’s desert climate, TEP works to limit its water use through conservation efforts that extend from power plants to the company’s corporate headquarters, which includes low-flow bathroom fixtures and uses only harvested rainwater for landscaping irrigation. The company also prefers energy resources that use less water, like wind turbines and photovoltaic arrays.
Estimated annual water use for all of Arizona is 7,000,000 to 8,000,000 acre-feet.
Average annual TEP water use for power generation is 18,000 acre-feet.