Big batteries could power your entire house for a day

As I type this, all the food in my refrigerator is slowly going bad, victim of a sudden problem that has taken out one of the circuits in my house -- the circuit that controls both the furnace and all the kitchen appliances. And while I patiently wait for an electrician to show up to fix the mess, I can't help but wonder: What if I didn't need the grid at all right now?

A new battery technology is in the works with big applications in mind. How big? 20 kilowatt-hours big, enough juice to power the typical home for a whole day. As Popular Mechanics notes, that kind of storage ability would be huge for solar users, who could use the monster-sized batteries to stash away excess energy as it was generated for use when the sun wasn't out. But even grid-connected households might want to get into the action too, with the prospect of a day-long battery backup in case the power goes out (or to stockpile power during cheaper off-peak hours) -- and without the hassle, noise, expense, and pollution of a generator.

The new battery technology uses a sodium and sulfur composition which has been around for some time. The problem: Sodium-sulfur batteries run extremely hot (600 degrees Fahrenheit), so they aren't easy to implement in a domestic setting. Utah-based Ceramatec has figured out a way to cool things down to about 200 degrees Fahrenheit, by using a ceramic membrane that limits the type of ions that can get through and thus keeps things from getting too hot.

Even better news: At a price of just $2,000, the system would be within range of most of middle America. However, there was no immediate word on how large the battery system might ultimately be when it arrives in its commercial version.

Watch for it -- if all goes well -- circa 2011.