The total amount of water withdrawn to create steam and cool power generation plants has declined 14 percent over the past three years, according to a new report from the U.S. Energy Information Administration.
Power generators take the water from rivers, lakes and aquifers to cool equipment, among other uses. EIA data shows that the total withdrawal amount fell from 62.3 trillion to 53.2 trillion gallons, while the water intensity of U.S. power generation dropped from an average of 15.2 to 13.2 gallons per kWh.
Electric power generators account for about 40 percent of total water withdrawals in the United States and are the largest source of U.S. water withdrawals followed by irrigation and public use, according to the EIA. About 800 thermoelectric power plants in 2017–coal, natural gas, nuclear, oil, and others–met EIA’s 100-MW capacity cooling water reporting threshold and account for in excess of 95 percent of total U.S. thermoelectric generation.
These plants require water to create steam to drive the turbines and cool and condense steam. In 2017, the total volume of water withdrawal by these thermoelectric power plants was 53.2 trillion gallons, more than twice the total water amount that flows over the Niagara Falls every year.
In 2014, the coal-fired portion of the generation sector dominated the outtake of water at nearly 40 percent of the whole, while natural gas accounted for less than 30 percent. Three years later, natural gas-fired generation was the top taker of water and coal had dropped to about 30 percent.
The EIA report says that the decline in water withdrawals by electric generation was mainly due to the increases in renewable energies and natural gas. Wind and solar require almost no water, while combined-cycle power plants withdraws less water per kWh than coal-fired plants because 32 percent of its generation is non-thermal, according to the report.