The results are in. Japan’s Kaneka has set a new energy conversion efficiency level for the first photovoltaic (PV) silicon solar cell to exceed 26 percent efficiency in converting sunlight into electricity. The company’s commercial-sized solar cell was able to convert 26.3 percent of sunlight into electricity, besting the previous record level of 25.6 percent efficiency.
The efficiency of a solar cell and a solar panel is important because the more efficient a PV device is, the more power it can produce in a smaller space, like a home rooftop. Currently the most efficient commercially available silicon solar panels are made by SunPower and Panasonic.
The company and its partner in the research, New Energy and Industrial Technology Development Organization (NEDO), originally announced its results last September, but this week they were published in the journal Nature Energy and were verified but the US’s National Renewable Energy Laboratory (NREL). At that time the company said: “This record-breaking result will advance technical development of crystalline silicon solar cells and contribute significantly to reducing the cost of power generation through use of high-efficiency solar cells.”
The device is an amorphous silicon/crystalline silicon heterojunction solar cell. In the journal’s abstract they report: “The cell achieves a certified conversion efficiency of 26.3 percent, showing that silicon solar cells are more efficient than ever and suggesting that more efficient silicon solar panels are on the way.”
The theoretical efficiency limit of single layer silicon solar cells, according to the Shockley Queisser Efficiency Limit, is 29.1 percent. But the researchers, and lead author, Kunta Yoshikawa, also proposed a path to approaching the theoretical conversion efficiency limit of silicon.
Other solar devices have pushed passed the limit but they use multiple layers of PV material. Each layer converts a different part of the sun’s light into electricity. NREL, which maintains a chart of all the record efficiencies, showed that currently the most efficient solar cell was made by Fraunhofer, ISE and Soitec and reached a 46 percent efficiency level.Tweet