Inside Clean Energy: Here’s How Compressed Air Can Provide Long-Duration Energy Storage
A grid that runs mostly on wind and solar, part of the future that clean energy advocates are working toward, will need lots of long-duration energy storage to get through the dark of night and cloudy or windless days.
Hydrostor, a Canadian company, has filed applications in the last week with California regulators to build two plants to meet some of that need using “compressed air energy storage.” The plants would pump compressed air into underground caverns and later release the air to turn a turbine and produce electricity.
The stored energy would be able to generate hundreds of megawatts of electric power for up to eight hours at a time, with no fossil fuels and no greenhouse gas emissions. Long-duration storage includes systems that can discharge electricity for eight hours or more, as opposed to lithium-ion battery storage, which typically runs for up to four hours.
This project and technology have potentially huge implications for the push to develop long-duration energy storage. But the key word is “potentially,” because there are many companies and technologies vying for a foothold in this rapidly growing part of the energy economy, and the results so far have been little more than research findings and hype.
“Their technology is not overly complicated,” said Mike Gravely, a manager of energy systems research for the California Energy Commission, speaking in general about CAES. “Compressed air is a very simple concept.”
