Plant efficient, flexible
Salem Township business banks on demand for energy
By Susan Schwartz
Published: September 5, 2023
SALEM TWP. — It may seem like a paradox, but company officials say the country’s effort to wean itself off fossil fuels will help the natural gas plant here. In fact, they’ve bet more than a billion dollars on it. That’s how much it cost to build the Caithness Moxie Freedom Generating Station five years ago.
“In our view, a new, state-of-the-art plant like this, which reduces emissions and is also flexible — we can go from minimal load to full load in half an hour — will do well,” said Gary Keevill. The senior vice president for Caithness Energy spoke during a recent tour of the plant for state legislators. More people are buying electric cars, and using heat pumps to heat and cool their homes and businesses. Electrical demand is going up, Keevill noted. As of 2020, the U.S. Department of Energy says, 20% of power was coming from windmills and solar panels. That share is increasing, but “you need a system that can react if the wind stops blowing, or the sun stops shining,” Keevill said.
Together, the station’s two generators can produce up to 1,100 megawatts. That’s enough to power 900,000 homes, Keevill told state Sen. Lynda Schlegel Culver, R-Sunbury, state Rep. Mike Cabell, R-Butler Twp., and James May, regional director for U.S. Rep. Dan Meuser, R-Dallas.
Caithness Energy and Moxie Energy teamed up to build the station here six years ago because they could tap into the gas lines bringing natural gas from Bradford County and feed the resulting power into the existing Susquehanna 500 kilovolt transmission line, said Tom Copus, director of operations for Caithness.
According to the Department of Environmental Protection, in 2021, the plant reported producing 2.86 million tons of carbon dioxide. That’s 3.2 million less than a coal plant would have created, Keevill said. And while the U.S. Department of Energy says simple cycle gas turbine plants are 20% to 35% efficient, Copus reports the Caithness Moxie Freedom plant is 63% to 64% efficient. The trick, Copus explained, is in using the hot exhaust created by burning the natural gas to create steam.
Electricity is produced when a rod-shaped magnet spins inside a cylinder of fixed copper bars. When one of Caithness Moxie Freedom Generating Station’s two generators first fires up, the burning gas spins a turbine that, in turn, spins the magnet. That produces 300 megawatts, Copus said.
In a standard gas plant, that would be the end of the process. But at this gas plant, the exhaust, which is 1,200 degrees Fahrenheit, is used to heat water running through thousands of tubes, creating steam, according to Jack Monahon. He’s general manager of operations for the local plant. The gas exhaust, now 212 degrees, released through the stacks, contains the plant’s carbon emissions.
Meanwhile, the steam powers a second turbine, which adds its power to spinning the same magnet, Copus said. That allows the generator to produce around 500 megawatts, he said.
After the steam passes the turbine, the plant uses 30 gargantuan fans to cool it back into water. The water is recirculated to start the process again. Monahon reports the plant circulates 100,000 gallons of water at a time, reusing 70% to 80% of it. The rest is released as vapor. Even so, each generator draws about 20,000 to 30,000 gallons of water from wells each day, Copus said. That’s still much less than the nuclear-powered Susquehanna Steam Station a few miles away, which has a permit to take 40 million gallons per day from the Susquehanna.
Caithness Moxie Freedom Generating Station doesn’t have to run on natural gas, Keevill said. General Electric, which made the plant’s high-efficiency gas turbines, says the plant can burn hydrogen instead, he said. The only by-product of burning hydrogen is water — 100% green. It’s not practical — currently, there is no economical way to produce enough pure hydrogen to fuel a power plant. But that could change, he said. Likewise, researchers are working to find a way to capture and store carbon dioxide as a liquid underground. If they succeed, the plant has plenty of land it could use for carbon storage, Keevill said. The site includes 150 acres, according to the company website.
Paid for rescue engine
Up to 650 people at a time worked to build the plant, the company said. These days, it employs 24 people — 12 operators, six managers, five maintenance workers and an instrument controls technician, Monahon said. During the maintenance shutdowns that take place twice a year, another 10 to 60 people work there.
The company also has supported $800,000 in local projects, Keevill said. That includes $400,000 pledged to the Salem Township Fire Co. Before leading the tour, power plant officials presented firefighters with their seventh installment toward that promise — a check for $22,500.
Deputy Fire Chief Jon Baltzer thanked them for the pledge. “Without that, we wouldn’t have the rescue engine,” he told them. The engine is a combined fire engine and rescue vehicle, he said.
Susan Schwartz covers the Berwick area. She can be reached at 570-387-1234, ext. 1306, and firstname.lastname@example.org.