Drive through most neighborhoods around the world, and you are likely to find at least a few homes that have solar panels installed on the roof for collecting electricity from the sun. The challenge for solar panels that are used in residential and industrial applications today is the inefficiency of the panels at turning sunlight into electricity. The average panel offers yields in the 17-19% range.
A more efficient solar panel means much more energy harvested from the sun, making solar panels more viable as an alternative form of energy. Researchers from a company called Insolight, a spin-off of the Ecole Polytechnique Federale de Lausanne (EPFL), have created new residential solar panels that are nearly twice as efficient as regular panels. These new solar panels deliver yields of 29% according to independent lab tests.
The new panels use a patented optical system to concentrate sunlight on a kind of mini photovoltaic cell normally used in satellites. Solar panels of the type used on satellites are generally very expensive, to keep costs down the team developed a protective glass that allows the placement of optical lenses that concentrate sunlight up to 100x and direct that sunlight to the very small surface of the high-performance cells.
The design means that the solar cells need to take up less than 0.5% of the solar panel surface. A mechanism that shifts the cells horizontally by a few millimeters allows the panels to follow the sun throughout the day. Since the highly efficient panels Insolight designed are so small, they can be laid over the top of conventional solar panels to increase yields.
The hybrid approach is particularly effective in cloudy weather because it can generate power even under diffuse light. The new panels are the same size and shape as existing solar panels and are installed the same way. The designers say that the technology could cut household energy bills by up to 30% in sunny regions; the first commercial product using the tech is expected in 2022.
The team says that their panels have been tested in a variety of weather conditions. Testing found that the panels kept working without any issues in heat waves, storms, and winter weather. The 29% yield of the panels was verified in testing by the Institute of Solar Energy at the Technical University of Madrid (IES-UPM).