The USGS Water Science School
Water Science water-use pages
Categories of Use:
National Water Use Program
Information and Data
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 2010, about 161,000 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 45 percent of total water use, 38 percent of total freshwater withdrawals for all categories, and 50 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, 2015