Multimillion-dollar power line project needed to make up for closure of Springdale power plant

The shutdown of the coal-fired power plant in Springdale is forcing Duquesne Light to spend between $12 million and $17 million to reconfigure a transmission line in Plum.

When GenOn’s Cheswick Generating Station stopped producing electricity in 2022, it reduced the amount of power being generated locally and created a need for more to be transferred into the area from other generators, Duquesne Light spokeswoman Alyssa Battaglia said.

Duquesne Light, FirstEnergy and PJM Interconnection, the regional power grid operator that coordinates the movement of wholesale electricity in Pennsylvania and 12 other states, worked together on a solution.

“The new interconnection point with FirstEnergy’s transmission system will increase the grid capacity, allowing for more power flow into the area and improved service to customers,” Battaglia said, adding the upgrade will “ensure the safety and reliability of the system.”

PJM assigned the project to Duquesne Light and First- Energy, PJM spokeswoman Susan Buehler said. The state Public Utility Commission approved it.

“Essentially, PJM has identified important transmission upgrades to several transmission lines to continue to provide safe and reliable electric service in the region,” she said.

Work on access roads is scheduled to start in April, with installation of structures and new wire starting in September with a December target completion date, according to the project’s timeline. Restoration of access roads should be finished in June.

All work will be within Duquesne Light’s existing rights of way or on property owned by Duquesne Light, according to the PUC order. Electric service will not be interrupted.

The project includes reconfiguring four existing Duquesne Light transmission structures to establish interconnection points with FirstEnergy transmission lines.

It also includes upgrading about 3 miles of transmission line from the new point of interconnection near Old Leechburg Road at Edenburg Drive to Duquesne Light’s Plum substation near Larry Mills Park.

According to the PUC order, Duquesne Light said reconfiguring the transmission line is needed to alleviate multiple thermal overload violations. “Thermal overload” is another term for the line exceeding its rating because of too much power flow, Battaglia said.

Deactivating the Cheswick Generating Station in the northeast portion of its system resulted in increased power flows from the lines in the southern and central portions of the Duquesne Light system. PJM identified a number of reliability criteria violations, which Duquesne Light says stem from the change in power flows occurring because of the retirement of the power plant.

Creating a new interconnection point with the FirstEnergy transmission system and upgrading the line to increase its capacity will address these issues, Duquesne Light told the PUC.

In its PUC filing, Duquesne Light said interconnecting with FirstEnergy will allow more power flow into the Duquesne Light system from the northeast and alleviate the potential overloads on four transmission lines. Upgrading the lines will address potential overloads on the transmission line as a result of the interconnection.

“We have not seen the lines overload since the plant deactivated,” Battaglia said. “Our operations center works closely with PJM and their operations center to monitor the flow on these lines and have the ability to make some system adjustments to reduce the impact until the project is completed.

“There are no major concerns with the health of these assets. The main driver for the project is to increase the capacity to accommodate the increase in power flow,” she said.

The project includes replacing about 3 miles of existing wires and 29 existing wooden pole transmission structures. Four poles to be installed for the new interconnection point will be steel, and the remaining 25 to support the upgraded line will be wood.

The new structures will be taller. While the existing transmission structures being removed range from about 52 to 70 feet tall, the new structures range from about 65 to 75 feet.

Also related to the shutdown of the coal-fired power plant in Springdale, Duquesne Light is increasing the capacity of one of its underground transmission cables in the city of Pittsburgh by adding cooling equipment on existing utility property, Battaglia said.

That project is under construction and expected to be finished before the summer peak period begins in June, she said. The cost was not disclosed.