Record Demand Strains Grid

Utilities 'on Edge' As Stifling Heat Drives Up Usage

The agency that coordinates power distribution across the mid-Atlantic took emergency steps yesterday to try to reduce the demand for electricity, as the third day of a punishing heat wave triggered fears that the grid was being strained to its limit.

Temperatures reached 100 degrees in parts of the Washington area yesterday, and the combination of heat and humidity created a heat index that topped 110 in some spots. Similar highs and more humidity are predicted for today.

There were small bits of good news: The high temperatures at Reagan National, Dulles International and Baltimore-Washington International Thurgood Marshall airports did not quite set the records that had been predicted. And an unexpected breeze blew away enough smog that the region dodged a Code Red pollution alert.

But the prevailing story was wilting, smothering heat -- heat so unbearable that, as people from Washington to Boston sought to escape it, they put record-breaking loads on the region's power infrastructure.

"We expect to be really pushing the limit of what's available, in terms of usage," said Ray E. Dotter, spokesman for PJM Interconnection, which handles power distribution for 51 million people in the District and in Maryland, Virginia and 11 other states. Yesterday, power usage in the network exceeded the record it had set the day before, of 144,000 megawatts.

In response, the network directed its utilities to activate programs in which certain large customers, in exchange for rate discounts, agree to curtail energy use during periods of high demand. Not all of the utilities in the PJM network have such programs, but the agency said every bit would help.

"We want more of a cushion than what we see we're going to have," Dotter said, noting that usage was uncomfortably close to his network's theoretical capacity of 164,994 megawatts. "You want to have a cushion there to cover something going wrong."

Power was a particular concern in New York, where LaGuardia Airport hit 100 degrees and Con Edison demand nearly reached the record set Tuesday.

Conservation measures in the city changed the look of some city landmarks -- lights on bridges and the Empire State Building were kept dark, and the Nasdaq stock exchange turned off its seven-story electronic sign in Times Square. But all that apparently wasn't enough: By evening, scattered power outages were reported in all five city boroughs.

In this area, both Pepco and Baltimore Gas and Electric broke their records for electricity demand, both of which had been set Tuesday. "Everybody's on edge," Pepco spokesman Bob Dobkin said. Dominion Virginia Power, which serves much of Northern Virginia, would not know its usage numbers until today, a spokesman said.

Late last night, Pepco reported that about 6,000 homes in its service area had lost power, with 3,850 in the District and most of the rest in Montgomery County.

In response to a directive from the PJM network, Dominion activated a voluntary program that requires participating commercial customers to cut consumption when the grid is under stress in exchange for a rate discount, a Dominion spokesman said.