Photo credit: Christopher Pearce
Professors Martin Green and Mark Keevers of UNSW have built a device that sets a world record for efficiency on sunlight-to-electricity using unfocused light – which is the type of sun that hits our roofs according to SMH.
The research team stated that the mini-module converts 34.5% of received solar energy into electrical power. It was confirmed by the US National renewable Energy Laboratory and the result has eclipsed the 24% efficiency that was achieved by an 800 square-centimetre commercial module that was developed by Alta Devices in the United States. The module by the UNSW measures 28 square centimetres. General efficiency for commercially available solar panels is 14%-22%.
Other solar cells have obtained higher efficiencies from unfocused sunlight but were results received before the solar cells were placed into prototypes or modules that can be scaled up for any commercial use.
According to senior co-researcher and senior research fellow at UNSW Dr. Mark Keevers, their intention for the device is to be suitable for rooftop photovoltaics but the proposition is for a longer term. What the team have done is a very early stage prototype. Although the research was a bit expensive, the team’s next step is to check and use the prism and the associated spectrum-splitting to make more affordable modules that can go on the roof of any house. Professor Green, co-researcher and director of the Australian Centre for Advanced Photovoltaics added that commercial application is more than 10 years away still.
The UNSW solar cell is designed to maximize the energy squeezed out of light that hits the receiver. This is achieved through a triple-junction cell that absorbs energy in the three discrete wavelength bands of light as it travels from the sun. Any unused infrared light is filtered out by solar splitter filters into a fourth junction that further increase the module’s efficiency. Most common domestic silicon-wafer solar cells take energy from the sun in just one hit thus a lower proportion of light to electricity.
Developments such as these efficient solar cells will surely push more innovations in the field of renewable energy. Although it is still in the development stage, we hope that this technology will be commercially available and at a more affordable price to let anyone take advantage of unlimited and cheaper energy sources.