After a new round of record high temperatures during the first two days of the summer of 2012, now is a good time to discuss a major study that projects what the rising temperature of water used to cool power plants will do to power generation over the coming decades.
It has happened a few times already--a power plant shutting down, because the water needed for cooling is too hot. The Browns Ferry Nuclear Plant had to stop operating last year when the water in the Tennessee River became too warm. Power reductions for the same reason have also happened at French nuclear reactors.
About 90% of America's power plants require water to cool them, and their steam turbines operate poorly or not at all, if the temperature of the intake water is too hot.
Now a study by European and American scientists concludes that rising river and water temperatures endangers the operation of up to 16% of America's generation capacity over the coming decades.
http://www.eurekalert.org/pub_releases/2012-06/uow-nac053112.php. As average air temperatures increase and the ratio of record highs to lows expands, water temperatures are rising too.
Temperature records for the Susquehanna River, for example, show an approximately 4-degree warming of its waters over the last 4 decades. Similar temperature increases have already happened on other waters and more heat is ahead.