This story originally appeared on Spotlight PA.

As billions of federal dollars for clean energy projects become available to Pennsylvania, state lawmakers are increasingly talking about making the commonwealth’s energy network greener. But underlying those discussions are big questions about the future of the state’s electrical grid.

Major policy decisions are on the table, like regulating new hydrogen production and carbon capture industries, capping emissions, and speeding up permitting.

But many Republicans say they’re concerned that in the coming years, energy production will fall short of growing demand — both from Pennsylvania residents and from entities outside of the state that purchase its power. They also fear that passing legislation to incentivize clean energy production or capping emissions will worsen shortages.

Environmental advocates say concerns about grid reliability are exaggerated and serve as excuses to slow the clean energy transition. Many also argue that clean energy is the solution to potential shortages.

Pennsylvania gets its electricity from PJM, a grid operator that serves 13 states in the Northeast and Midwest.

PJM oversees a marketplace in which producers, like natural gas and coal plants and a smaller number of solar, wind, and other renewable energy producers, participate. Utilities can then buy the electricity generated by these producers and supply it to homes and businesses.

Pennsylvania is a major supplier of energy to PJM’s grid, accounting for up to a quarter of the total electricity produced, and is the second biggest energy producer in the country.

In recent years, PJM has reported multiple times that its energy demand is set to outpace its energy production, especially as more power plants close. The company has predicted that over a fifth of its existing power generators, largely coal and natural gas plants, will retire by 2030.

Some states have already had issues meeting demand. In Maryland, a coal power plant notified PJM that it intended to close down, but PJM found that shuttering it would negatively affect grid reliability and refused to approve its closure. The plant, Brandon Shores, has been forced to stay open and could continue operating until 2028. Environmental advocates accused PJM of lacking foresight during its planning of the plant’s closure.

Republicans in Harrisburg say incidents like this make them wary of transitioning away from coal and natural gas too quickly.

“I think the PJM has a real crisis looming on its hands,” state Senate Majority Leader Joe Pittman (R., Indiana) told Spotlight PA. “I see no real reliable plan to replace the megawatts that are due to come offline in the next few short years.”

Pittman said that energy production from natural gas and coal is essential to a reliable grid, and supports an all-of-the-above approach to energy. He argued for reducing permitting requirements for natural gas and oil companies, opposing any cap-and-trade program that would put a price tag on carbon emissions, and buildout of nuclear plants and carbon capture.

“There’s no secret that the demand for electricity is growing. It’s growing more rapidly than anybody anticipated,” Pittman said. “So we have to be very honest with ourselves that it’s going to take all forms of electricity production to ensure we have a stable grid.”

Environmental advocates agree that the deficit between energy production and demand has increased and will continue to grow, but they argue the issue can be solved by federal regulators and PJM speeding up the approval and construction of clean energy projects.

Tom Rutigliano, a senior advocate for the Natural Resources Defense Council who focuses on PJM, said no proposal is being considered in Pennsylvania that would immediately shut down all gas or coal power plants. He added, many grid concerns could be solved by PJM speeding up its approval process for new energy producers, most of which are solar.

“PJM has to be able to get these new power plants connected much, much quicker than they are and they’ve proven unable to keep pace with getting the new plants on in turn to keep up with the retirements,” Rutigliano said.

According to Rutigliano, PJM’s approval procedure was meant to handle a small number of connection requests from generators with large capacities, like coal and natural gas plants.

However, over 90% of the current projects awaiting approval from PJM are from renewable sources such as solar and wind, which generate less energy but would be much more numerous.