Storing (Renewable) Energy using Air Compressors

Lightsail: http://www.lightsail.com/

From http://www.greentechmedia.com/articles/read/LightSail-Energy: 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.

When the captured, pressurized air is released back through the system, the heated water is re-infused into it. That heated air can return more of the energy stored by the system than can other CAES processes.

Links:

http://www.nantucketproject.com/danielle_fong_a_time_for_urgency

http://www.lightsail.com/blog/making-economical-clean-energy-at-planet-scale/