A Funnel For Sunlight

摘要

Solar panels convert the most light into electricity when the sun shines directly on them, but as soon as it wanes, so does efficiency. A new antireflective film coating could help panels collect sunshine at 96 percent efficiency from nearly any angle. Developed by scientists at Rensselaer Polytechnic Institute, the film consists of seven layers of nanoscopic silicon and titanium-oxide rods arranged in increasing densities, with the topmost nearly as porous as air. This funnel-like setup captures light from almost every direction and focuses it onto the photovoltaic panel while also inhibiting reflection. The film, which is about one hundredth as thick as a human hair, could easily be applied to any solar panel, says lead researcher Shawn-Yu Lin, and would help collect 20 percent more light while eliminating the need for the expensive hardware usually used to rotate solar panels as the sun moves. Before Lin can sell the film, he must find a way to protect the outermost layers from the wind and heat, a process that he says may take another year.