Nanotechnology Makes Solar Power More Affordable

Researchers at Rensselaer Polytechnic Institute in New York, reported November 3 that they have created a “near perfect” solar panel. The solar panel has a special coating that captures 96.7 percent of the light incident upon it, compared to 67.4 percent for the untreated silicon panels commonly in use today.

The problem of absorption is one of the issues that keeps the electricity output of solar panels low and the cost of solar power high. Solar panels are designed to absorb sunlight at a single angle. This means that either the efficiency of a panel changes over time (as the Sun moves across the sky), or a mechanism has to be installed to make sure the panels are always pointed at the sun. The new coating made of nanorods allows the solar panel to absorb light from any angle.

The nanorods form a multi-layer coating that works like a series of funnels. The top layer of nanorods takes the light hitting the panel at wide angles and bends it to a slightly narrower angle. Successive layers narrow the angle even further, funneling the light so it hits the active region of the panel at a ninety degree angle, eliminating the panel’s need to rotate with the sun.

Aside from using coatings, other scientists have tried to overcome the absorption problem with a design change. One example is a tube-shaped panel instead of a flat panel. Solyndra, a California solar startup, has been working on this technology and has received over $1.2 billion in contracts from various customers.

Another problem with solar is efficiency, the amount of captured light that is converted into energy. Coatings and panel shape do not affect efficiency, but maybe these guys in Idaho will be able to fix that problem. And their new panel works at night by capturing heat in the form of infrared light, which is invisible to humans!
These solar advancements must continue to decrease in price, however. Solar companies are having trouble in a tough economy, and the falling price of oil will continue to make a switch to renewable energy a challenge.

Hopefully Moore’s Law will help us out.

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