Researchers at Penn State have found that reusing depleted oil and gas wells could improve compressed-air energy storage (CAES) efficiency, offering a greener way to support renewable energy.
CAES systems store energy by compressing air underground during periods of low demand and releasing it to generate power when demand rises.
The team’s new geothermal-assisted CAES design takes advantage of natural underground heat in abandoned wells, improving system efficiency by 9.5%.
“This improvement in efficiency can be a game changer to justify the economics of compressed-air energy storage projects,” said Arash Dahi Taleghani, Professor of petroleum and natural gas engineering at Penn State. “And on top of that, we could significantly avoid the upfront cost by using existing oil and gas wells that are no longer in production. This could be a win, win situation.”
The Environmental Protection Agency estimates there are 3.9 million such wells in the United States.
Reusing these sites eliminates the need to drill new wells, reducing costs and offering new economic opportunities in former energy regions.
“If we use existing wells, we are basically hitting two birds with one stone,” added the professor.
“First, we are sealing these wells. That stops any potential leaks. And then if we are repurposing these wells for energy storage, we are still using the infrastructure that is in place in these communities.”
The research was supported by the U.S. Department of Energy.
