U.S. Northeast grids monitoring heat wave, say power is sufficient

(Reuters) - Utilities in the U.S. Northeast expect to have enough power to keep the lights on as homes and businesses crank up air conditioners to escape a heat wave, the region's power grid operators said on Tuesday. Temperatures in the biggest U.S. Northeast cities were all expected to reach the 90s Fahrenheit (32 Celsius) this week, the highest so far this summer. Grid operators have asked businesses to reduce demand when possible. "We expect to have sufficient capacity through the heat wave but we will continue to closely monitor regional electricity supplies," said Marcia Blomberg, a spokeswoman at ISO New England, which operates the grid for the six New England states. Meteorologists at AccuWeather forecast temperatures would slide from a high of 96 degrees Fahrenheit on Sunday to 92 on Tuesday in New York. Temperatures are also expected to fall modestly later in the week in Philadelphia and Boston. PJM Interconnection, the nation's biggest grid operator, forecast electric demand would reach 148,542 megawatts (MW) on Tuesday, exceeding the peak of 145,942 MW on Monday, highest so far this year, before declining on Wednesday as many businesses close for the Fourth of July holiday. One megawatt can power about 1,000 U.S. homes. PJM, which operates the grid serving 65 million people in 13 states from New Jersey to Illinois, said it expects to have over 165,000 MW of power resources available. To prepare for the heat, PJM asked companies that operate generation and transmission facilities to avoid unnecessary equipment maintenance. The peaks expected this week in PJM were well short of the grid's all-time high of 165,492 MW set in 2006. The New York Independent System Operator (NYISO), which operates that state's power grid, forecast demand on Tuesday of 30,530 MW, just shy of Monday's interim peak of 31,468 MW. The all-time high of 33,956 MW was set in July 2013. The NYISO activated its demand response program on Monday but not on Tuesday to reduce consumption in New York City. Consumers participating in such programs receive lower rates or other forms of compensation for reducing usage at these times. This helps power companies and grid operators reduce strain on the grid. ISO New England said peak demand would reach 23,800 MW on Tuesday, more than on Monday, but short of the grid's all-time high of 28,130 MW set in August 2006. ISO New England said it had over 28,200 MW of resources available. (Reporting by Scott DiSavino)