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New England grid operator expects to have enough power for summer

April 29 (Reuters) - The U.S. New England power grid operator expects to have enough resources to meet peak electric demand this summer when business and homeowners crank up their air conditioners to escape the heat.

ISO New England, the grid operator for the six New England states, forecast usage would peak at about 26,660 megawatts with temperatures of about 90 degrees F (32.2 degrees C) and 28,965 MW in an extended heat wave with temperatures of 95 F.

Both forecasts include the demand-reducing effect of energy-efficiency measures, the ISO said.

Last summer, power usage peaked at 27,379 MW on July 19, 2013. The all-time peak demand record was 28,130 MW set on Aug. 2, 2006.

One megawatt can power about 1,000 homes in New England.

"Widespread energy-efficiency efforts across New England have reduced the region's forecasted peak demand for electricity," said Vamsi Chadalavada, executive vice president and chief operating officer of ISO New England, in a statement.

To meet demand this summer, the ISO said it has secured 29,135 MW of generation, 1,280 MW of electric imports and 700 MW of demand-response resources through its power capacity auction.

Demand-response programs compensate consumers who reduce usage during times of tight system conditions.

The ISO noted the remaining coal and oil-fired units at the 585-MW Salem Harbor power plant in the Greater Boston area will retire June 1.

"This retirement is the first in a series of expected large resource retirements in the coming years that will reduce the available generating capacity in New England, resulting in the need for new resources," Chadalavada said.

To replace units like Salem Harbor, the ISO noted generating companies are relying more on natural gas to fuel power plants.

The ISO warned that "difficulties can arise" in supplying gas to generators during the summer because of planned and unplanned pipeline maintenance even though fuel supply concerns are more significant during the winter, when pipelines transporting the fuel to heat homes and businesses are already at or near full capacity.

Gas and power companies are better coordinating their efforts following recent orders by federal energy regulators to make sure there is enough gas (or other fuels) available to keep power plants running reliably.

The biggest power companies in New England include units of National Grid Plc (LSE: NG.L - news) , Northeast Utilities (NYSE: NU - news) , Iberdrola (TLO: IBE-U.TI - news) SA, NextEra Energy Inc (NYSE: NEE - news) , Dominion Resources Inc (NYSE: D - news) , Entergy Corp, Exelon Corp, NRG Energy Inc (NYSE: NRG - news) and Public Service Enterprise Group Inc. (Reporting by Scott DiSavino; Editing by Bernadette Baum)