One of the annoying arguments against solar and wind power is "intermittency" — the fact that the sun doesn’t always shine, and the wind doesn’t always blow. This allegedly proves that solar and wind can’t be anything more than add-ons to a more reliable coal-based grid.

I say "annoying" because I don’t have a solid, easy comeback. But it something about it sticks in my craw.

The obvious way to address the problem would be storage — store the energy and use it when the sun/wind isn’t "on." But store it how? If we ever produced electric cars, or even plug-in hybrids, the batteries therein could be used as a kind of distributed storage, feeding into the grid when circumstances require it. Or we could develop industrial-scale batteries. I’ve heard some interesting stuff about using methanol to store the energy. And of course there’s always hydrogen fuel cells.

Robert Rapier discusses storing wind energy as compressed air, based on this MSNBC story. Sounds promising to me.

Anybody out there know more about this stuff? What’s the best way to overcome intermittency?