It’s been said that once solar power efficiency gets to 40% it’ll be a tipping point for the mass use of solar panels. Now we can see if that is true as a team of researchers partnered with industry has developed technology to make it so solar energy conversion can regularly hit 40.4%.
The advance involved two steps. Three solar panels were stacked to capture energy from different wave lengths of sunlight, and then excess light from the stacked panels was directed by a mirror and filters to a fourth PV cell, making use of energy previously discarded.
“This is our first re-emergence into the focused-sunlight area,” said Professor Green, who pioneered 20 per cent-efficiency levels in similar technology in 1989.
The institute was prompted to revisit the technology in part because of Australian companies’ efforts to develop large-scale solar towers using arrays of mirrors to focus sunlight on PV cells.
One of those firms, Melbourne-based RayGen, collaborated with UNSW on the project. It is building a plant in China with an solar conversion rate of about 28 per cent across the year.. “We’d take them to the mid-30s” for future projects with the technology jump, Professor Green said