Warmer water and reduced river flows in the United States and Europe in recent years have led to reduced production, or temporary shutdown, of several thermoelectric power plants. For instance, the Browns Ferry Nuclear Plant in Alabama had to shut down more than once last summer because the Tennessee River's water was too warm to use it for cooling.
A study by European and University of Washington scientists published today in Nature Climate Change projects that in the next 50 years warmer water and lower flows will lead to more such power disruptions. The authors predict that thermoelectric power generating capacity from 2031 to 2060 will decrease by between 4 and 16 percent in the U.S. and 6 to 19 percent in Europe due to lack of cooling water. The likelihood of extreme drops in power generation—complete or almost-total shutdowns—is projected to almost triple.
"This study suggests that our reliance on thermal cooling is something that we're going to have to revisit," said co-author Dennis Lettenmaier, a UW professor of civil and environmental engineering.
Thermoelectric plants, which use nuclear or fossil fuels to heat water into steam that turns a turbine, supply more than 90 percent of U.S. electricity and account for 40 percent of the nation's freshwater usage. In Europe, these plants supply three-quarters of the electricity and account for about half of the freshwater use.
While much of this water is "recycled," the power plants rely on consistent volumes of water, at a particular temperature, to prevent the turbines from overheating.
Reduced water availability and warmer water, caused by increasing air temperatures associated with climate change, mean higher electricity costs and less reliability.
While plants with cooling towers will be affected, results show older plants that rely on "once-through cooling" are the most vulnerable. These plants pump water directly from rivers or lakes to cool the turbines before returning the water to its source, and require high flow volumes.
Read More:
http://www.eurekalert.org/pub_releases/2012-06/uow-nac053112.php