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T H E E N E R G Y WAT E R C O L L I S I O N
10 Things You Should Know E between energy and water, problems for one can create problems for the other. In places where using energy requires a large share of available water, or where water resources are scarce or stressed by competing pressures (such as the needs of farmers or of local ecosystems or, increasingly in many parts of the United States, by climate change), the energy-water connection can turn into a collision—with dangerous implications for both. NERGY AND WATER are woven into our daily lives and strongly linked to one an- other. Producing energy uses water, and providing freshwater uses energy. Both these processes face growing limits and problems.1 In most power plants, water cools the steam that spins the electricity-generating turbines. Rening transportation fuels requires water, as does producing fuels—for example, mining coal, extracting petroleum, or growing crops for biofuels. Using water in our homes and businesses requires getting it there, treating it, heating it, and more. Because of these links e 10 facts below summarize the water impacts of our energy choices—and ways to address them.
THIRSTY FOR POWER—Keeping U.S. power on each day requires more water than 140 New York Cities. e electric sector withdraws 143 billion gal- lons of freshwater per day.2 More than half of the country’s 104 nuclear power reactors use once-through cooling (see the text box on p. 4).3 Each of these plants withdraws 25 to 60 gallons of water for each kilowatt- hour of electricity it generates.4 Coal plants with similar cooling systems typically with- draw almost as much—20 to 50 gallons per kilowatt-hour—even without considering the water needed to mine coal or store coal waste from power plants (see the text box on p. 3). ose gures mean that for a nuclear or coal plant to generate the electricity for one load of hot-water laundry (using electric appliances), 3 to 10 times more water must be withdrawn at the plant than is used to wash the clothes.5 1
WITHDRAWAL SYMPTOMS—In the southeastern United States, power plants account for two-thirds of all withdrawals of freshwater. Nationally, the amount of freshwater withdrawn to cool power plants is roughly the same as that for crop irrigation.6 In the Southeast, electricity’s water withdrawals easily top agriculture’s: power plants there withdraw an average of 40 billion gallons of freshwater every day, or 65 percent of the region’s total.7 2
Some plants lose or “consume” large amounts of the withdrawn water to evapo- ration (see the text box on p. 2): a typical 600-megawatt coal-red power plant con- sumes more than 2 billion gallons of water per year from nearby lakes, rivers, aquifers, or oceans.8,9
Average daily water use by U.S. family of four
Assuming its home is powered by a coal-red or nuclear power plant that takes freshwater for once-through cooling, an average family of four directly uses 400 gallons of freshwater per day, while indirectly using 600 to 1,800 gallons through power plant water withdrawals.
indirect use via power plant