The U.S. largest electrical utility, has pleaded guilty to nine criminal violations of the Clean Water Act for polluting four major rivers with coal ash.
SNL says the closures represent about 4% of installed coal capacity in the U.S. and it will make up a third of nationwide coal plant retirements between 2010 and 2015.
The recurring phenomenon — a warming of the Pacific Ocean as part of a complex cycle linking atmosphere and ocean — has in the past affected mine output, triggering price spikes.