Solar cells beat the blues - November 05, 2008
Solar panels seem like an obvious way to generate electricity on the cheap, but they are flawed in a number of ways. They’re pretty inefficient, and they need to be pointed right at the sun to take advantage of its rays.
So it is good to learn of a new coating made from nanometre sized rods that helps solar panels soak up almost 100% of the sun rays that hit them. This is a big improvement on losing a third of the rays such as happens in conventional solar panels. The news comes out of Rennselaer Polytechnic Institute in Troy New York, and a team led by Shawn-Yu Lin. (Press release)
The coating is actually seven layers of carpets made from tiny silicon dioxide and titanium dioxide rods. The rods sit at different angles so can capture sunlight from anywhere. Each layer transmits a different wavelength of light, so that the whole spectrum is covered.
Clever, eh? Clever enough to hit the headlines. The typical blue tinge of solar panels is a direct indication that not all the light is being used, Lin explains to Reuters. What we want is dark, black panels. It doesn't say what colour panels that have a few layers of nanorods slapped on them are, but I'm guessing it's very close to blackest black. The DailyTech calls the design ‘nearly perfect’.
The rods are not unique, though. Other groups are working on similar systems. Nate Lewis and Harry Atwater at Caltech have been working on nanocarpets for a while, as part of a bigger project to help split water using sunlight (see this feature)
Image: Rensselaer/Shawn Lin
