April 30 (Reuters) - The New England power grid in the Northeast United States expects to have enough electricity to keep consumers' air conditioners humming this summer, said the regional grid operator ISO New England. The ISO said demand in the six-state region this summer could peak at 26,690 megawatts (MW) under normal weather conditions and rise to 28,985 MW under extreme conditions like an extended heat wave. Last summer, electricity usage peaked at 25,880 MW. The all-time peak was set on August 2, 2006 at 28,130 MW. One megawatt can power about 1,000 New England homes. The ISO said this summer's peak forecasts included energy efficiency measures that could reduce demand by 1,150 MW. "Energy-efficiency measures across the region have reduced our forecasted peak by reducing consumer demand for electricity," Vamsi Chadalavada, executive vice president and chief operating officer of the ISO, said in a release. The power plants in New England can generate about 31,700 MW of electricity if all were running at the same time. In addition, the grid has lined up about 1,100 MW of imports from neighboring systems and 700 MW of demand response resources the ISO can call on to reduce electric use when needed. As always, the ISO noted it has procedures in place to manage the grid in case unplanned power plant or transmission line outages occur, including outages due to fuel limitations. The ISO said those procedures include calling on demand-response resources, importing emergency power from neighboring regions, and asking businesses and residents to voluntarily conserve energy. Chadalavada said the grid was "keeping an eye" on other factors that could have an impact on grid operations like natural gas pipeline maintenance, which could affect gas supplies to some power plants. New England is dependent on natural gas for electricity production. In 2012, natural-gas-fired plants produced 52 percent of the power generated in the region. He said the ISO is coordinating with the pipeline companies to ensure the supply is adequate for power generation during the summer pipeline maintenance season. Pipeline companies usually conduct maintenance during the summer because gas is not needed to heat homes and businesses, the ISO said. Chadalavada also noted the high demand for liquefied natural gas (LNG) overseas has resulted in higher prices on the global market. He said LNG deliveries into New England may be reduced this summer, which could affect power system operations. The biggest power companies in New England include units of National Grid Plc, Northeast Utilities, Iberdrola SA, NextEra Energy Inc, Dominion Resources Inc , Entergy Corp and Exelon Corp.