Danielle Fong wants to reinvent the power grid — using giant tanks of compressed air. Photos: Wired/Ariel Zambelich
LightSail’s prototype sprays a dense mist into the compressed air tanks, and this absorbs the heat produced during compression. Water can store heat far more efficiently than air, and with this mist, Fong says, the prototype more easily stores and releases power. It heats up the tanks to temperatures that are only about 10 to 20 degrees warmer than the environment, as opposed to several thousand degrees. The tanks are still pressurized to about 3,000 pounds per square inch — and Fong hopes to increase that amount — but since the power is stored at lower-temperatures, it’s easier to insulate the tanks.
According to Fong, her system doubles the efficiency of compressed air, from about 35 percent to roughly 70 percent.