Great compression
Let’s go back to high school physics again for another concept: pressure. When you squeeze something into a smaller space, you increase the pressure.
Converting this pressure into useful energy is the idea behind compressed air energy storage. All you need is an underground salt cave. If you have electricity to use, you can run pumps to push air into the cave. Then, when you need to get power, simply release the valve and let the escaping air spin the turbine to generate electricity again.
There are only a few such facilities operating worldwide, one in Germany and the other in Alabama. In the past, they have been associated with fossil fuels, as they typically work alongside natural gas-fired power plants. But now companies want to redefine compressed air storage, using it for renewable energy and expanding its uses.
Earlier this year, local governments in California signed contracts with Hydrostor, which is building the world’s largest compressed air storage facility. Instead of relying on natural geological conditions, Hydrostor will drill three shafts deep into the ground to store compressed air.
It’s a billion-dollar project and could be operational as early as 2028 to store energy and help power California’s grid using nothing but air.
Other groups want to take a different approach to the same concept. Energy Dome, an Italian startup, wants to compress carbon dioxide instead of air to store energy. It wouldn’t require large underground storage facilities at all — check out my story on the Energy Dome from last year for more details here.
Earth to the battery
Some groups are also looking to combine these new energy storage approaches with power generation, making new power plants more flexible.
