The innovation, as described by the article: * power can be stored in tanks of compressed air * compressing air makes it heat up * heat dissipation from the

The innovation, as described by the article: * power can be stored in tanks of compressed air * compressing air makes it heat up * heat dissipation from the hot compressed air reduces storage efficiency * the solution here is to mix water with the air * the water stores a great deal of heat, reducing the temperature of the compressed air without reducing the amount of heat stored * lowering the temperature of the compressed air reduces the heat dissipation, increasing storage efficiency It's a pretty slick solution. The heat capacity of water is so enormous--I've often been frustrated by it when I'm waiting for water to boil. But here they're turning it around and using it as a tool. It's a very elegant problem/solution fit.