BOSTON – New England will not face California-style rolling blackouts this summer, the operator of the region’s electric power grid said Tuesday.

ISO New England said the addition of several new power plants during the past two years would supply enough electricity to satisfy demand for the region’s 6.5 million electric consumers.

“This is not California,” said ISO New England Vice President Stephen Whitley.

“There is ample supply of electricity to meet our demands this summer.”

In fact, New England, which typically imports more electricity than it exports, is adding so much power-generating capacity that it likely will export electricity to New York and other power grids this summer, Whitley said.

But a citizens’ advocacy group chided the ISO for focusing on more power plants instead of using less electricity.

“Policy makers should spend as much time thinking about energy efficiency as they do about building new gas plants,” said MassPIRG spokesman Derek Haskew. “Increasing supply is futile until we prioritize energy efficiency.”

Residential and business customers still may be asked this summer to conserve electricity during special “Power Watches,” when stretches of very hot and humid weather force people to turn to energy-guzzling air conditioners and fans to keep cool.

Such requests are not uncommon in summer, when New England’s electricity demand is usually at its highest.

Last year, ISO New England twice asked consumers to cut down on power use voluntarily by raising air conditioner thermostats, shutting off air conditioners when no one was home, and doing laundry in the evening instead of daytime when demand is highest.

In summer 1999, one of the hottest on record, ISO New England issued seven “power watches.”

California has been hit with rolling blackouts after electric companies cut production, citing limits imposed on the rates they could charge consumers. Energy experts say more blackouts will hit California this summer.

But in New England, “We’re going into a period of very healthy supply,” Whitley said. “California basically hasn’t built any new capacity in 10 years.”

ISO New England tracked weather data and electricity usage to predict a peak demand this summer of 23,650 megawatts – the most ever.

The previous demand record was 22,544 megawatts on July 6, 1999.

Regulators say the economic expansion – including Internet companies that fill warehouses with air conditioner-chilled computers – is fueling the demand.

But New England has added plenty of power plants to satisfy it, Whitley said.

The region’s power grid has added about 1,000 megawatts of generation capability since June 2000, and another 1,600 megawatts of capacity are expected to be up and running by this summer.

That would bring New England’s total capability to 28,100 megawatts this summer.

One megawatt is enough to fuel about 1,000 homes on an average day.

New England will have a “cushion” between capacity and demand of about 19 percent this summer, far above the typical 2 percent cushion in California, Whitley said.

A power plant industry spokesman, Neal Costello of the Competitive Power Coalition of New England, criticized the ISO’s efforts to regulate the market – for example, by setting a maximum price during peak demand of $1,000 per megawatt hour that suppliers can charge.

Those regulatory efforts keep some companies that would generate electricity only on a few of the highest-demand days of the year from entering the market, Costello said.

In general, consumers usually pay about 10 percent to 20 percent more for electricity during the summer because demand is higher. In Massachusetts, those rates are set by electric companies and approved by state regulators, not set by the ISO.