Promising efforts to store wind power

Wind power is not practical at this time because the wind blows when it wills, not when we need the power. We need to be able to store the power from wind for use at the times of peak power demand. Here is a promising development CNN Money :

One problem perhaps more than any other has proven a drag on the long-term prospects for wind power: how do you turn on the lights when the wind isn't blowing? A New Jersey company said Tuesday it has joined with Michael Nakhamkin, one of the top thinkers in energy storage, to develop new ways to trap wind-generated power in underground reservoirs. Nakhamkin has helped develop technology to pull excess energy off the power grid _ usually at night when usage has waned _ to run compressors that pump air into sealed, underground caverns that once held oil, salt or natural gas. During periods of higher demand, the air is released and heated to run air expansion turbines. ... Compressed air in a cave about a third the size of the New York Giants' football stadium _ roughly 21,500,000 cubic square feet _ would be enough to power a 300-megawatt turbine for 8 hours, Daniel said. That load could power about 200,000 homes _ a small city _ for about 8 hours, said John A. Stratton, an electrical power systems professor at the Rochester Institute of Technology. "That's a healthy load," he said. "It's going to get us through the peak of the day by using excess energy at night." While the process isn't totally efficient _ energy is lost while being transferred _ it "makes wind a very different kind of energy than it is today," Stratton said.