Monday, May 05, 2008

Local electricity storage

A few posts back, I indicated I would do some Googling about household electrical storage, so that my future solar Stirling engine powered house would still let me watch TV at night.

Seems there's not many choices around. Of course, the truly dedicated can buy a huge number of lead acid batteries already, but they have a pretty short life. One site claims that nanotechnology will let us build superbatteries, but as to how realistic this proposal is, I have no idea:
Today, using lead-acid storage batteries, such a unit for a typical house to store 100 kilowatt hours of electrical energy would take up a small room and cost more than $10,000. Through revolutionary advances in nanotechnology, it may be possible to shrink an equivalent unit to the size of a washing machine and drop the cost to less than $1,000. With these advances the electrical grid can become exceedingly robust, because local storage protects customers from power fluctuations and outages. Most importantly, it permits some or all of the primary electrical power on the grid to come from solar and wind.
Still, there does exist one form of battery which allows a lot of electricity to be stored. Futurepundit talked about them last year: sodium sulphur batteries. He links to a USAToday story about them, which includes a photo.

They are big and expensive and used for a many houses, not just one. They appear to be largely a Japanese idea. The New York Times reported last year that one company in America is looking at using them for storing windpower. (The article also notes that they operate at more than 800 degrees F, which makes it sound like you wouldn't want even a small one in your backyard.)

So, OK, they won't fit in my backyard, but they sound a fairly promising idea if used on neighbourhood scale.

Of course, another Japanese idea may help in any plan to live off the grid: house sized fuel cells, which I have mentioned before. I wonder: can you turn these on and off easily, as required, and not affect their efficiency in the process? And can you get away with using bottled natural gas for them, instead of mains gas?

Funny how many of these energy ideas are coming from Japan, hey?

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