Seeing the Water-Energy Connection

What’s the thirstiest industry in the United States? If you thought of agriculture, you’re spot on. But coming in second–guzzling 40 percent of U.S. freshwater withdrawals–is a surprisingly different undertaking: electricity.

Environmentally motivated researchers and policymakers are just beginning to grasp the importance of illuminating the complex relationship between water and energy, Sustainable Industries reports. The clock is ticking. By 2025, the United Nations forecasts half the world will meet with freshwater shortages. By 2050, upgrade that pinch to scarcity spanning three-quarters of the planet. And, oh, wouldn’t you know: All forms of energy production require water (and on the flip side, heating, treating, and distributing water requires energy too).

“Increased implementation of renewable power sources is key to securing future water supplies, but when it comes to water use, not all renewables are created equal,” writes Sara Stroud, SI‘s Bay Area correspondent.

Wind and solar photovoltics are among the lesser offenders; they require only one gallon of water for each megawatt hour of electricity produced (excluding water used in manufacturing). (A megawatt is one million watts, and one megawatt hour could power 400-900 homes for that hour.) Compare that to corn-derived ethanol, which sucks anywhere from 5 to 2,000 liters of water for each liter of fuel. That higher number comes courtesy of agriculture undertaken in arid states, like California and Colorado.

“Federal incentives happened so quickly without evaluating consequences,” Dulce Fernandes of Network for New Energy Choices told SI. “If we are investing in alternatives, we have to get it right.”

Source: Sustainable Industries

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