Environmental Engineering Reference
In-Depth Information
CHAPTER 24
Water and Power
THE WATER-ENERGY NEXUS—AND COLLISION
About 4% of all electricity used in the U.S. is used to move and treat water and
wastewater.
—the EPA
Water and power are so closely intertwined that it is virtually impossible to manage one
resource without taking the other into account. After agriculture, power generation is the
greatest user of water in the world. In the United States, some 190,000 million gallons
of water is used every day to produce electricity. Water is used in the production of oil,
natural-gas, coal, ethanol, solar, wind, and hydroelectric power, and, especially, to cool
power plants. According to the federal Sandia National Laboratories, the production of
each kilowatt-hour of electricity using coal—the cheapest, most common, and one of the
dirtiest fossil fuels—requires 25 gallons of water.
Americans use as much water indirectly, by turning on lights and heating their homes,
as they do directly, by brushing their teeth or spraying their lawns. The simple act of run-
ning a faucet uses energy; heating tap water is responsible for 9 percent of residential
electrical consumption; water treatment and distribution use about 4 percent of the na-
tion's annual electrical output, and in some regions that number can be much higher.
As the population grows and shifts from the cool Northeast to the hot Southwest,
the demand for power is surging and setting off disagreements over how much water to
devote to energy. In the East, competition among the power industry, developers, and
environmentalists has led to showdowns over Maine rivers, the New York watershed,
and the coastal waters of Florida. In the Midwest, competition among irrigation farmers,
oil-shale developers, biofuel entrepreneurs, and growing urban populations is helping
to drain ancient stores of groundwater. In the Sunbelt, dozens of planned solar power
plants—large, high-tech projects in the vanguard of the renewable-energy boom—will
require billions of gallons of water to produce steam to run their turbines, for cooling,
and to maintain solar mirrors. But in 2009 growing restrictions on water use in Nevada,
Texas, and California slowed many of these solar projects. Similar confrontations over
resources are rippling throughout the global economy.
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