New Rules and Old Plants May Strain Summer Energy Supplies – NYTimes.com

The E.P.A. estimates that a rule on air toxins and mercury that it expects to complete in November will result in a loss of 10,000 megawatts — or almost 1 percent of the generating capacity in the United States. Electricity experts, however, say that rule, combined with forthcoming ones on coal ash and cooling water, will have a much greater effect — from 48,000 megawatts to 80,000 megawatts, or 3.5 to 7 percent.

… The most likely replacement for the coal plants is new natural gas-powered generators. But PJM and others are complaining that if the E.P.A. follows its intended schedule, utilities will not have much time to decide whether to close or upgrade their old plants, and no one will have time to build new ones.

… The new peaks will shape the planning of the grid. In the eastern United States, electricity is mostly generated near where it is consumed, and if some producers disappear, someone will have to build new generation or new transmission to supply the area from a distant source.

“You always manage toward the peak, and have a reserve margin based on your latest peak,” said Tom Williams, a spokesman for Duke Energy, which does business in areas that experienced a new peak.

Peak supply is also becoming a vexing problem because so much of the generating capacity added around the country lately is wind power, which is almost useless on the hot, still days when air-conditioning drives up demand.

via New Rules and Old Plants May Strain Summer Energy Supplies – NYTimes.com.