Storing Energy Underwater

This article discusses the advantage of compressed air energy storage (CAES) system. CAES has been proposed as an alternative to pumped hydro storage for large-scale, bulk energy management. CAES systems typically rely on electrically driven air compressors that pump pressurized air into large underground geological formations such as aquifers and caverns for storage. When the power is needed, turboexpanders connected to generators convert the compressed air back into electrical energy. Like pumped hydro, CAES can be scaled to sizes compatible for supplementing large renewable energy facilities. The lifetime costs for a CAES system can make it work as a means for storing cheap off peak electricity and selling it during peak hours, but capital costs and difficulties finding suitable geological structures have limited the technology’s applications. To make CAES more useful for storing wind-powered electricity, the systems have to become less expensive and have greater flexibility in sitting.