2nd heat wave in Western Pa. strains power grid but utilities handle extra demand

This summer’s heat has pushed the mercury to 90 degrees and higher for 11 days, prompting people to keep the air conditioners humming day and night. It has also strained the electricity lines carrying power to homes and businesses, area utility companies said.

But while the system may be stressed by demand, there is a sufficient amount of power available on the grid used by Western Pennsylvania utilities, said Jeff Shields, a spokesman for PJM, a Valley Forge-based regional transmission organization that coordinates the movement of wholesale electricity in 13 states, including Pennsylvania. In addition to the electrical power on the grid, PJM also can tap power being held in reserve, Shields said.

PJM issued a “hot weather alert” for Pennsylvania and other states in the Midwest and along the Atlantic Coast. On Wednesday, the high in the Pittsburgh region could reach 90, with a heat index of 97, according to the National Weather Service.

With hot days and only slighter cooler nights, PJM said it could approach the summer forecasted peak of approximately 148,000 megawatts. Recent hot weather in the PJM region resulted in preliminary peaks between 142,000 and 145,000 megawatts. One megawatt is enough electricity is provide power for about 800 homes, per PJM.

The Pittsburgh region had 11 days of temperatures in the 90s in the first 20 days of July, including three straight through Monday and eight consecutive from July 3 to 10. The highest temperature during that span was 94 on July 6. June saw one day reach 90 degrees.

“It’s on the high end” for the number of 90-degree days, but “it’s nothing unprecedented,” said Jason Frazier, a meteorologist with the National Weather Service in Moon.

The region typically sees about seven days where temperatures reach 90 or above.

Greensburg-based West Penn Power, which serves 720,000 customers in the state, has had few outages this summer, usually affecting only a handful of customers, said a company spokesman, Todd Meyers.

The company spent $106 million from 2016 to 2019 through its infrastructure improvement plan, a targeted investment that is in addition to its regular maintenance, Meyers said.

“We’re seeing positive benefits,” he said, noting that without it, the hot weather likely would have caused more power outages for West Penn Power. “If we had this heat wave in 2000 to 2010, we likely would have seen more outages in the system.”

In times of high power demand during the summer, the extra electricity transmitted can cause power lines to sag by several feet, Meyers said.

Duquesne Light Co., which serves more than 500,000 customers in Southwestern Pennsylvania, had power outages affecting about 17,000 customers during the first heat wave in early July, but not all of those were due to the weather, said Ashley Macik, a company spokeswoman. Some were due to motor vehicle accidents and other incidents, Macik said.

“There’s a potential for more outages” with the demand for more power, Macik said.