One problem with wind power is that you can never be sure when the wind will be blowing. If you rely on wind power, you've got problems when the weather chooses not to cooperate, which is like... always! One obvious way to collect the excess electricity to be used later would be with big batteries, but there are other ideas regarding the best way to store the power. Take for instance this scheduled power plant
in Dallas Center, Iowa. In lieu of storing the power as electricity, the plan for this group is to store the energy in a giant underground "balloon". Well, not exactly a balloon, but a cavern of porous sandstone layers 3,000 feet under the ground. We've never seen balloons made of rock, but if that's what it takes to make green energy available to the masses... well then, rock balloons it is!
[Source: Ecotality via Engadget