Off the Grid

There's an interesting article in the New York Times today about the rise of solar power. Apparently the market for solar is growing rapidly--expected to expand by as much as 150 percent between now and the end of 2008. And the new generation of solar panels is 50 percent more efficient at converting sunlight to electrical power than the last.

Up until recently, the market for solar energy has been somewhat stagnant, and the technology's relatively poor efficiency--around 14 percent--might be attributed to lack of market demand. It occurs to me, though, that the new appetite for solar may be part of a larger trend away from centralized sources of power.

Big power grids are inherently inefficient, since all the cabling necessary to farm out the electricity generated at a large centralized power plant to far-flung consumers is the source of a lot of electrical resistance. A little over 7 percent of the power generated in the US is lost during transmission and distribution because all the electrical resistance caused by power lines converts electrical energy into heat, which dissipates without doing any useful work. That's a huge waste. And it gets worse every year as suburbs expand and people continue building further outward from central power plants.

But renewable sources of energy have a big advantage here. In addition to being sustainable and less polluting than combustible sources of electricity like oil and coal, many renewable energy sources can be located at the site of consumption. Solar arrays are often placed at the location they are intended to power. And the same can be done with wind generators. Other experimental renewable sources of energy like tidal and wave power also lend themselves to small power grids, if not on-site production.

US industry seemed to lose interest in gas cooled pebble bed nuclear reactors, like the one being tested in South Africa, when it became clear that they were better suited for smaller power grids. They don't appear to be tailored for our current model of huge unwieldy power grids.

But as energy security becomes more important to the US, and scarce resources force us to look more carefully at issues of power efficiency and conservation, it seems likely that decentralized power will look more and more attractive to Americans. Of course, business interests are still aligned on the side of centralized power, but if tech startups and entrepreneurs with new sensibilities like the ones mentioned in the Times succeed, the market for sustainable energy may begin to shift dramatically and the technologies themselves may greatly improve.