Australian Researchers Develop The World’s Most Efficient Solar Panels
Gizmodo, May 18, 2016. Image credit: WOODPUNCHER
Most commercially available solar panels only are able to convert between 15 and 22 per cent of the sunlight they’re exposed to into electricity. As part of an ongoing effort to improve the efficiency of increasingly important solar technology, a team from UNSW has created a solar cell module that boasts a world record efficiency rate of 34.5%.
This result completely eclipses the previous world record for a scalable solar module, which was set at 24 per cent by Alta Devices in the US, making the new result almost 44 per cent better than its predecessor. The tiny module tested by the UNSW team used a surface area of only 28 square centimeters to achieve this result, though the technology is quite expensive to produce, meaning it may be a while before it sees proper commercial use. Still, it’s another exciting step towards reaching the theoretical limits of this technology.
The record was set by Dr Mark Keevers and Professor Martin Green of the Australian Centre for Advanced Photovoltaics, and confirmed by the US National Renewable Energy Laboratory. The 28 square centimeter four-junction mini-module uses the light-catching properties of a prism to extract the most energy from each beam of sunlight. The module splits incoming light into four bands, with energy extracted from one of the four junctions at its most efficient wavelength.
The new module is a bit different. It combines a silicone cell on one side of a glass prism and a triple-junction cell on the other. The triple junction cell uses a combination of three layers, each with a different chemical composition — indium-gallium-phosphide, indium-gallium-arsenide and germanium. Energy is extracted by each successive junction at its most efficient wavelength, with the unused light passing through the layer to the next level.