Meanwhile, you CAN store electricity, even grid electricity. They just don't have that set up yet. I guess you'll call it 'Infrastructure.' Sulphur Sodium batteries. Maybe other kinds too. But it's already being done. Not sure the setup cost.
Also vanadium-redox liquid flow batteries. (What a problem to have!)
Pumped storage (pumping water from the lower end of a hydroelectric dam to the upper reservoir during low-demand times) is inefficient, but...when you have an excess of wind-energy, it's better than a sharp stick in the eye (as Stevie Wonder used to say).
Oh yeah, leave us not forget those flow batteries. http://en.wikipedia.org/wiki/Flow_battery This could prove to be a "Quick charge" method for cars, oh so much work to be done, though.