Roland Saul Posted about 2 years ago Compressed air in tanks or held under ground on a large scale.When the sun goes down you blow off steam and run your generators. I took a road trip a couple of years ago and visited a roughly 100 turbine wind farm in Prince Edward Island, on the east coast of Canada. That wind farm was using power from the turbines to generate hydrogen. Once "canned", the hydrogen could be transported or stored like any other lp gas. Seems like the same sort of hybrid you're talking about. As far as I know, the project is still up and running.