Another natural gas-fired power plant has come online in Pennsylvania, this time south of Pittsburgh, while an engineering firm has started commissioning a similar facility on the other side of the state.

Omaha-based Tenaska said its Westmoreland Generating Station, about 40 miles south of Pittsburgh in shale country, has entered service. The 940 MW facility can generate enough power for roughly 940,000 homes. The plant, which sells power into the PJM Interconnection started operations on Dec. 21.

Tenaska Pennsylvania Partners LLC, which includes Tenaska affiliates, Mitsubishi Corp. subsidiary Diamond Generating Corp. and J-Power USA Investment Co., owns the facility. Tenaska closed on $780 million of financing for the plant in early 2016 when construction started.

Across the state, in Peach Bottom Township about 60 miles south of the capital Harrisburg, engineering, procurement and construction firm McDermott International Inc. said it’s started commissioning activities at Calpine Corp.’s York 2 Energy Center. The firm said it successfully achieved first fire of units 5 and 6 and steam blows at the combined-cycle gas-fired facility.

“First fire and steam blows are critical milestones for the power plant as it validates the operability of the new facility,” McDermott said.

York 2 Energy Center is an 828 MW, dual-fueled plant located at the same site as Calpine’s York Energy Center.  Its combustion turbines will primarily use clean-burning natural gas but can also run on ultra-low-sulfur diesel fuel oil to serve the PJM market. McDermott said it would continue commissioning activities and expects the project to be finished sometime in 1Q2019.

The plants are the latest in a broader gas-fired building boom in the region that has unfolded in recent years as low natural gas prices have pushed power generators back toward the fuel.

PJM serves 65 million people in all or parts of 13 states and the District of Columbia. Gas-fired generation has proliferated in PJM’s footprint, driven primarily by rising production in Ohio, Pennsylvania and West Virginia. There are currently 26 gas-fired facilities under construction or being upgraded in the market, according to PJM’s services queue.