Monday, October 20, 2008

Energy vs. Water

Bellagio Hotel Fountain in Las Vegas

This morning I addressed the New England Library Association in Manchester, a lovely New Hampshire mill town ablaze in autumnal colors. My talk was about Future-Proof Design as a response to dramatic change. I picked up the current issue of Scientific American Earth 3.0 in the airport on the way here, a new magazine devoted to "Solutions for Sustainable Progress." It is full of important articles, but the cover story, "Energy vs. Water: Why Both Crises Must Be Solved Together"made me add another slide to my PowerPoint.

I was aware that one of the major energy bills for most cities is the one for pumping drinking water and sewage. What I had never thought much about is the amount of water used to produce that energy. The premise of the article, by Micheal E. Webber, is that as clean water or what he calls "liquid gold" gets more scarce it may cause us to rethink alternative energy sources that use huge amounts of clean water in their production. He points out, for example, that an ethanol vehicle that travels 100 miles also uses 130 to 6,200 gallons of water (depending on the source of the ethanol and whether it came from an irrigated field), while the same car using gasoline would use 7 to 14 gallons of water. An electric car would use 24 gallons of water to go the same distance, due to the water used in cooling the power plant. Power sources like wind or solar use virtually no water which could reverse that math.

Lake Mead Water Intake Structures near Hoover Dam
Where Las Vegas gets its water and power

Webber points out the intimate connection between energy and water in Las Vegas, where Lake Mead water elevation would only need to drop another 50 feet before Hoover Dam and the electric power it produces to goes off-line. He reports that recent droughts in the Southeast set up situations where nuclear power plants were nearly shut down due to lack of cooling water from rivers that were suffering from drought and the growing demands for irrigation and domestic water use. Such situations are causing conflicts among states that share water resources and between protectors of wildlife and industrial, agricultural and development interests. This Special Issue contains some other articles that make it a "must read." Fortunately, it is available on line.

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