Black Silicon Increases Solar Panel Efficiency
NREL Develops Cost-Effective Black Silicon
Black silicon will make solar panels more efficient. Have you ever noticed that it is hotter inside black cars than white cars? Objects are a certain color because of what wavelengths of light they reflect. White things reflect all wavelengths, and black things absorb them, so a black car absorbs most of the visible spectrum of light, while a white car reflects them. Solar panels can only convert the light they absorb into energy, so using black silicon can greatly increase their efficiency.
Normal solar panels are a silvery color. Panels made out of black silicon look black. This means they absorb more of the sun's rays and hence more energy. Traditional solar panels will max out their efficiency at about 25%. Black silicon panels should be able to get higher than that.
Black silicon has been around for quite a while, but it has been expensive. Several companies have been working on more efficient means of making the tiny imperfections and pits in the surface of the black silicon panels that give the panels their color and allow them to collect more light. Sionyx uses laser pulses and sulfur gas to create black silicon. Some researchers in Munich bore holes in the silicon with gold.
An innovation presented last week by NREL researchers claims to make black silicon panels more cost effective. Their new, cheaper technique to produce black silicon is based on the Munich technique, but it uses chloroauric acid instead of gold which greatly simplifies the process.