Engineers at the University of New South Wales (UNSW) in Sydney have built photovoltaic cells capable of harvesting almost 35 percent of the sun’s energy – shattering the previous world record of 24 percent.
At only 28-square centimetres, the new cells cover less surface area than the 800-square centimetres taken up by the previous record holders. The UNSW solar cell configuration works by splitting incoming sunlight into four separate bands.
Mark Keevers, one of the university's researchers, said: “This encouraging result shows that there are still advances to come in photovoltaics research to make solar cells even more efficient.
"Extracting more energy from every beam of sunlight is critical to reducing the cost of electricity generated by solar cells as it lowers the investment needed, and delivering payback faster."
However, four-junction cells aren’t going to end up on a rooftop panel in the near future as they are more expensive to produce and maintain than traditional single-junction cells. They’re better suited to so-called “solar towers”, which use mirrors to aim light at a series of cells which then convert it into electricity via heat.
The UNSW team is now looking to scale up the size of their new cell to 800-square centimetres to see what kind of efficiency can be achieved at these dimensions. At present, the limit is thought to be 53 percent.
Read the May 2016 issue of Energy Digital magazine