Thursday, July 31, 2008

Is Solar Energy's Time Finally Near?

Yale's environment 360 thinks that solar energy's time is now (or at least in the next couple of decades). And while I think wind and nuclear will probably surge before solar, some recent advances in solar energy make me think that Yale might be right.

A couple of weeks ago, researchers at MIT announced that they had developed efficient new solar concentrators that could lower costs and increase efficiency by 10 to 15 percent. And today, New Scientist reports on new materials for solar cells that may increase the theoretical maximum efficiency of solar panels to 63% of the energy striking the panel.

The new materials achieve these results by embedding titanium and vanadium atoms into conventional semiconductors. These atoms can absorb photons in the lower-energy infrared range and have their electrons jump to a level that is half-way to what the visible light photons are reaching. Then, when another infrared photon strikes the material, the electrons make it the rest of the way to the higher energy state that is needed for producing photovoltaic electricity. In this way, panels made from the new material are capable of generating electricity from both the visible light and the infrared light striking them.

The 63% efficiency figure is, however, a theoretical maximum, and any panels actually made from this material will likely produce energy with lower efficiency levels. Additionally, some experts believe it may prove difficult to get enough titanium and vanadium into the silicon in order to properly reach the intermediate level without inhibiting the silicon's ability to do its job. So don't look for these new high-efficiency solar panels right away.

That said, when they figure out how to put this technology into SunSlatesTM, it might be time for my house to get a new roof....

No comments: