Wind Energy Storage: Compressed-Air Technology May be the Solution
Compressed-air energy storage plants are tackling the problem of holding captured wind energy so it can be available on demand to reduce dependency on coal. The air generated by windmills during peak production hours can be pumped into underground cavities, both natural sandstone formations and abandoned mines, to compress -- or squeeze -- the trapped air so when it is tapped, a large percentage of the stored energy is released.
The "bottled wind" concept is not new. Compressed air energy systems have been used by engineers for decades. Recent advancements have renewed interest in this technology, and General Compression received $17 million from investors to construct a full-scale prototype in conjunction with Duke Energy, who will integrate it into their smart grid technology. David Marcus, President and Founder of General Compression, admits “It’s a fractal problem. You have intermittency problems on every time scale.” Power generation stations with multiple energy carrier systems use dispatch orders to determine which source will be the most economically viable at any given time. "This is the first non-hydro renewables technology that can replace coal in the dispatch order,” said Marcus.