Next generation cells surpass limits of today’s cells and will accelerate rollout of cheaper, more efficient solar power
Solar power cells have raced past the key milestone of 30% energy efficiency, after innovations by multiple research groups around the world. The feat makes this a “revolutionary” year, according to one expert, and could accelerate the rollout of solar power.
Today’s solar panels use silicon-based cells but are rapidly approaching their maximum conversion of sunlight to electricity of 29%. At the same time, the installation rate of solar power needs to increase tenfold in order to tackle the climate crisis, according to scientists.
The breakthrough is adding a layer of perovskite, another semiconductor, on top of the silicon layer. This captures blue light from the visible spectrum, while the silicon captures red light, boosting the total light captured overall. With more energy absorbed per cell, the cost of solar electricity is even cheaper, and deployment can proceed faster to help keep global heating under control.
The perovskite-silicon “tandem” cells have been under research for about a decade, but recent technical improvements have now pushed them past the 30% milestone. Experts said that if the scaling-up of production of the tandem cells proceeds smoothly, they could be commercially available within five years, about the same time silicon-only cells reach their maximum efficiency.
Two groups published the details of their efficiency breakthroughs in the journal Science on Thursday, and at least two others are known to have pushed well beyond 30%.
“This year is a revolutionary year,” said Prof Stefaan De Wolf, at King Abdullah University of Science and Technology in Saudi Arabia. “It’s very exciting that things are moving rapidly with multiple groups.”
The current efficiency record for silicon-only solar cells is 24.5% in commercial cells and 27% in the laboratory. The latter may well be as close the cells can practically get to the theoretical maximum of 29%.
The solar industry is also part of the race to high efficiency.
Chinese company LONGi, the world’s biggest producer of solar cells, announced in June they had reached 33.5% in their research. “Reducing the cost of electricity remains the perpetual theme driving the development of the photovoltaic industry,” said Li Zhenguo, the president of LONGi.
Source: theguardian.com
