LightSail Energy has developed an advanced grid-scale compressed air energy storage (CAES) technology that stores mechanical energy rather than electrochemical energy. With CAES, an electricity-powered air compressor drives air into storage tanks and the compressed air can then be released on demand to generate electricity. The LightSail system captures and stores both the mechanical energy and the thermal energy used in compressing air. To do this, a water mist is infused into the compression chamber as the air is compressed. Water can hold 3,300 times as much heat as the same volume of air, and as such, it is able to capture the heat generated by the process more effectively. Both potential energy in the form of pressurized air and the heated (and therefore higher-energy) water can be stored. The LightSail team is working on the system’s round-trip efficiency and report they have “consistently achieved over 90 percent thermodynamic efficiency.” The company will ship its first product in 2013, with a unit size somewhere between half a megawatt to a megawatt. From GreentechMedia.com and www.lightsailenergy.com Link from David Schaller Sustainable Practices
