Concerned Scientists: Renewables Secure From Drought

Even those who don't believe humans are causing climate change have a hard time rebuffing the national-security argument—which contends that a diverse domestic energy portfolio makes the United States less vulnerable to disruptions of its energy supply.
Drought may not be the first threat that comes to mind, but the Union of Concerned Scientists contends that this summer's drought is already straining the operation of water-heavy fossil fuel and nuclear plants.
"Our power sector is built for a water-rich world, and when that world is water poor, power plants and electricity users face big risks," according to Erika Spanger-Siegfried, a senior analyst with the Union's Climate and Energy Program.
In a new post on the Union's blog, Spanger-Seigfried argues that solar and wind energy promote energy security not only because they make the nation less reliant on foreign oil, not only because they reduce carbon emissions that contribute to a hotter and drier world, but more imediately also because they make the nation less reliant on an failing water supply:
In 2005, power plants accounted for over 40 percent of all freshwater withdrawn in the U.S. At some power plants, a lot of the water they withdraw gets evaporated in the cooling process; at others, much of the water is discharged back to its source (albeit hotter). The bottom line: Most power plants need a huge, steady supply of water to operate, and in hot dry summers, that water can become hard to secure.
Texas mechanical engineering professor Michael Webber recently raised this issue in the New York Times, contending that "we withdraw more water for the energy sector than for agriculture. Unfortunately, this relationship means that water problems become energy problems that are serious enough to warrant high-level attention."
There are three types of "water-energy collisions," according to Spanger-Siegfried:
Energy plants don't have enough water and some have had to draw water greater distances to keep plants in operation.
The incoming water is too warm to cool the plants. "During a 2006 heat wave, incoming Mississippi River water became too hot to cool the two-unit Prairie Island, MN, nuclear plant, forcing the plant to reduce output by more than 50 percent."
The water discharged from the plants is warmer, posing a threat to wildlife, especially fish, and causing plants to seek permit exceptions or reduce production "Alabama’s Browns Ferry nuclear plant, on the Tennessee River, (cut) its output three of the last five summers, for example, and for five consecutive weeks in 2010."
The Union of Concerned Scientists believes the 2012 drought bears the marks of climate change, but offers energy security as a more immediate advantage of fossil-fuel and water-free energy sources, like wind and solar.