The method is used when it is not gusty enough topside for regular wind generation to work. PSEG Energy Holdings will provide around $20 million to Energy Storage and Power, a joint venture between itself and energy storage expert Michael Nakhamkin, according to the AP. The company will work on marketing the technology to wind generators, primarily using natural caves once occupied by gas or oil.
The air is compressed in the caves by using electricity from wind turbines (which, by the way, aren't the same turbines that the cave air spins). Cave storage should prove useful in many of the same areas that wind turbines will be going up. In Texas, for example, where oil tycoon T. Boone Pickens is investing billions in wind, many of the same oil reservoirs he helped to empty will be available. However, it should also be pointed out that this is one idea that has been floating about for several years -- and never got a venture investment, as far as I'm aware (PSEG is a large holding company). There are likely numerous reasons for that. Caves that stored fossil fuels for millions of years can still spring leaks, for one, and they may or may not be of a useful size. Also, the air in the caves can't provide an immediate substitute source of power if the wind dies down, mainly being used during longer windless periods. And it's not a totally clean solution; a natural gas turbine needs to be paired with the storage method, to heat the air (thus making it expand). Finally, energy is lost in all stages of the process, which translates into making the wind turbines working to store air less efficient. Still, the prospects for any storage technology look pretty good right now. And that has everything to do with the scale of new demand for it: According to a new study released this morning by BCC Research, the US market for wind systems will be worth $60.9 billion in 2013, up from $11.2 billion this year.