Two Double-A Cells at a Time

I received several comments on last week's post relating to energy density, mostly disputing my suggestion that low-density sources such as wind and solar could ever cover more than a fifth or so of our energy needs. That's really an argument for another day, though. The focus now, particularly for solar power, should be on how to provide 2% of our primary energy supply, not 10 times that. Company strategists should still be looking for applications that are less price sensitive, not trying to penetrate the mainstream market with a technology that's not ready. This article from Technology Review gives some useful hints.

When you evaluate the hierarchy of energy costs, grid-based power--even at the retail end--is pretty low, at least on average. Backup power is more expensive, but with an iron focus on high reliability, that's hardly the place for intermittent energy sources to attack. Battery power is further up the pyramid, and disposable batteries are close to the top, in terms of cost per kilowatt-hour of electricity delivered. Flexible solar cells, such as the ones described in the article, could be incorporated in device design in such a way as to reduce the required capacity of rechargeable batteries or eliminate disposable batteries entirely in some applications. In fact, the cost of solar is not the obstacle here, as it is in the residential market, since it is already at or below the cost of power from disposable batteries. The real issue is incorporating it into devices in a seamless way, without adding too much bulk or funky attachments.

If you want a picture of how alternative energy is likely to develop, don't watch the heart of the market, where petroleum products and large, central power plants have had a century to hone their competitiveness. Watch the margins, and watch trendsetters. A solar iPod, anyone?