State power grid said to be 'stable'

"No. In fact, the system is quite stable," said Terry Williamson, director of communications for PJM. "We feel we have adequate capacity."

PJM is the regional power pool, serving part or all of Pennsylvania, New Jersey, Delaware, Maryland and the District of Columbia. Its job is to keep the power grid stable and prevent blackouts or brownouts.

"We experienced our peak load on (July 17 and 18) when it was extremely hot," Williamson said. "Even then, we didn't contemplate any load-shedding."

Electricity usage on July 17 set a record at 139,746 megawatts, Williamson said. The old record was set on July 26, 2005, when 133,763 megawatts were used.

Load-shedding is a power industry term for rolling blackouts, when certain customers lose electric service to keep the system as a whole from going down.

"Voltage reduction" is the official term for brownouts, when the amount of voltage going to customers is reduced and lights may dim or air conditioners may not work as well.

Williamson said the last voltage reduction, of 5 percent, was on July 27, 2005, in Baltimore, the PECO Energy service territory, the eastern part of the PPL service territory and in New Jersey. The last load shedding was in 1994 after a severe ice storm.