Electricity Overseer Says Grid Must Grow

Resistance to New Lines Called a Threat

The electric-power industry in the mid-Atlantic region and other parts of the nation is not keeping up with long-term demand, the industry's reliability organization warned yesterday in its annual assessment.

The increasing use of wind and solar electricity sources, the eventual output of nuclear power plants being planned, and limits on greenhouse gas emissions will put new strains on the electricity transmission grid unless it can be strengthened, officials of the North American Electric Reliability Corp. said. Continued resistance to building high-voltage transmission lines threatens to increase the chance of power shortages, the organization said.

The amount of reserve electricity generation capacity available for emergency shortages will fall below a 15 percent safety margin by 2012 in the mid-Atlantic and Midwest and by 2009 in New England, requiring some combination of new power plants, more transmission lines and electricity conservation by consumers and business.

NERC, based in Princeton, N.J., has been assigned under federal law to enforce the reliability of the U.S. power grids -- a response to the Northeast power blackout in 2003. David R. Nevius, a NERC senior vice president, said at a news conference yesterday that the long-term reliability outlook this year is somewhat better than a year ago. But, he added, "Electricity peak demand in the United States is still projected to grow faster than the resources needed to serve it."

The demand for power in summer is expected to increase more than 135,000 megawatts nationally in the next 10 years, an 18 percent overall increase.

The construction of new power plants that are committed to deliver power at such peak times is projected to add 77,000 megawatts, a gain of 8 percent, NERC said. An additional 46,000 megawatts of "uncommitted" generating plant capacity might be available but cannot be counted on, NERC said. Those plants aren't required to run during shortages, are mothballed or cannot deliver power where it is needed.

In some parts of the country, including the Great Plains, the eastern Rocky Mountain states and Florida, utilities remain under state "obligation to serve" regulations and can be ordered to build power plants to maintain adequate reserve capacity.

That isn't the case in New England and the mid-Atlantic and Great Lakes regions, where electricity markets, not regulation, determine wholesale power prices, NERC said. There, grid operators rely on complex pricing formulas to create incentives for generators to build more plants. The Washington area's grid operator, the PJM Interconnection, has such a pricing strategy. Some state officials criticize the plan, saying it may raise power prices without assuring necessary plant construction.

NERC said those strategies "look promising." NERC President Richard P. Sergel added: "Obviously, they haven't been proven yet. We will track them very carefully."

About 2,000 miles of high-voltage lines were built in the past year, about a 1 percent increase. "The pace of proposed transmission projects in the U.S. appears to be accelerating," NERC said.

Maryland and Virginia bring in more than a quarter of their electricity supplies from other states, and the District imports 98 percent of its needs, according to the federal Energy Information Administration.

But proposals for new lines into the Washington area have been opposed by residents and public officials.

The Energy Department this month designated the mid-Atlantic, including the Washington metropolitan area, as a National Interest Electricity Transmission Corridor, because of persistent transmission congestion. The 2005 Energy Policy Act permits federal regulators to override states and approve construction of a line through a national corridor if states do not act within a year.