H2OAlliance Power Industry Working Group
The generating industry has a huge demand for water. The thermoelectric power sector accounts for 39% of total freshwater withdrawals in the United States. Power plants fueled by coal and natural gas use 2,800 and 2,300 liters, respectively, to produce one megawatt hour of
electricity. Nuclear power plants need more freshwater than gas-fired generators- 3,100 liters per megawatt hour—to keep from overheating. Water is also required in coal plants in conjunction with sulfur removal. Carbon-capture technologies would further increase power plants’ water needs.
The scale of water intake by individual plants is quite large. The big difference with other sectors is that only 2-5% of this intake is lost, due principally to evaporation, with the rest eventually being returned to surface water bodies.
A growing body of anecdotal evidence points to the materiality of water issues to the power sector globally. Low river levels, low water levels in hydro power reservoirs, lack of freshwater and exceptionally high temperatures, may force shut downs of nuclear power plants and thermoelectric plants, and increases in the average price of electricity.
Water-related shutdowns are expected to become more common as climate change intensifies summer heat waves and prolongs droughts in already arid areas. These include the places experiencing the fastest population growth.
Lack of water can also constrain generators’ growth potential. Power plants can face local opposition because of their need for large amounts of groundwater. Shifting to renewable energy sources does not necessarily resolve the problem. The production of one liter of corn ethanol requires 1,700 liters of water. Concentrated solar - using the sun to evaporate water and drive steam turbines requires more than 2,600 liters of water per megawatt hour.
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