Thermoelectric Power Water Use

Production of electrical power results in one of the largest uses of water in the United States and worldwide. Water for thermoelectric power is used in generating electricity with steam-driven turbine generators. In 2005, about 201,000 million gallons of water each day (Mgal/d) were used to produce electricity (excluding hydroelectric power). Surface water was the source for more than 99 percent of total thermoelectric-power withdrawals. In coastal areas, the use of saline water instead of freshwater expands the overall available water supply. Thermoelectric-power withdrawals accounted for 49 percent of total water use, 41 percent of total freshwater withdrawals for all categories, and 53 percent of fresh surface-water withdrawals.

One of the main uses of water in the power industry is to cool the power-producing equipment. Water used for this purpose does cool the equipment, but at the same time, the hot equipment heats up the cooling water! Overly hot water cannot be released back into the environment—fish downstream from a power plant releasing the hot water would get very upset. So, the used water must first be cooled. One way to do this is to build very large cooling towers and to spray the water inside the towers. Evaporation occurs and water is cooled. That is why large power-production facilities are often located near rivers, lakes, and the ocean.

 View a diagram of Georgia Power's Plant Scherer and see how it uses water.

Thermoelectric-power water withdrawals for the Nation, 2005

For 2005, withdrawals were an estimated 143,000 Mgal/d of freshwater and 58,100 Mgal/d of saline water. (All 2010 water use information is from the report Estimated use of water in the United States in 2010.) Thermoelectric-power water withdrawals were 41 percent of total freshwater withdrawals and 50 percent of total fresh plus saline withdrawals for the Nation in 2005. Surface water accounted for about 99 percent of the water used for thermoelectric-power production.

Thermoelectric-power withdrawals, by State, 2005

Trends in thermoelectric-power water withdrawals, 1950-2005

Thermoelectric power has been the category with the largest water withdrawals since 1965, and for 2005 comprised 49 percent of total withdrawals. The largest total and fresh and saline surface-water withdrawals were during 1980. Withdrawals by thermoelectric-power plants increased from 40,000 Mgal/d during 1950 to 210,000 Mgal/d during 1980. Withdrawals for thermoelectric power declined and then stabilized since 1980, despite the fact that total population has continued to rise; the total withdrawal of 201,000 Mgal/d for 2005 is slightly above that of 2000.

Thermoelectric-power water use, 2000

• Estimated Use of Water in the United States in 2000, USGS Circular 1268:
• Thermoelectric-power water use, 2000: Summary | Data table, by State | National map