Dive Summary:

• 2012's drought conditions in the U.S. threaten to severely impact the electric grid, and thermoelectric plants are uniquely at risk due to their cooling needs.
• The U.S. Energy Information Administration has mapped out all of the country's thermoelectric power plants according to cooling system type, explaining why some may be more at risk than others.
• Fresh water cooling systems in particular face problems when water levels drop, though salt water systems can also face challenges due to rising water temperatures.

From the article:

Prolonged drought can affect power plants that rely on large volumes of fresh water for a variety of reasons. Though there have been few reported problems this year, lower water levels are a potential concern for grid operators and system planners during periods of extended drought.

The map above shows the relative size of electric power plants, expressed in megawatts, for the subset of power plants that reported operating cooling systems, by type, that withdrew water for cooling during 2011 (the latest full summer season of data available). ...