Researchers at Ecole Polytechnique Fédérale de Lausanne (EFPL) recently announced the development of hybrid heterojunction technology based solar cells with a record energy conversion efficiency of 21.4 per cent.
Containing a layer of amorphous silicon just one hundredth of a micron thick deposited on both sides of a crystalline silicon wafer, the sandwich-type arrange improves the cell’s effectiveness.
While attaining 21.4 per cent on common materials, the researchers also claim to have broken the 22 per cent efficiency barrier on a less common substrate.
The results were validated by the Fraunhofer Institute for Solar Energy Systems (ISE) in Germany and will soon be published by the IEEE Journal of Photovoltaics.
The researchers say they expect to reach a production cost of 100 francs per square meter within three to five years - around AUD $104 at current exchange rates. They estimate such a surface area will be able to generate 200 - 300 kilowatt hours per year under Switzerland’s sunlight conditions.
The team, led by Professor Christophe Ballif, director of the EFPL’s Photovoltaics Laboratory (PVlab), presented their work at the recent European Photovoltaic Solar Energy Conference and Exhibition in Frankfurt.
Those interested in solar panels based on this type of cell don’t need to wait. Modules using HIT (Heterojunction with Intrinsic Thin layer) technology have been available for some time.
Panasonic’s 235 Watt HIT solar panel offers a cell efficiency of 21.1 per cent and an 18.6 per cent module conversion efficiency. Heat being the enemy of PV based power generation, HIT technology offers some attributes particularly attractive in countries such as Australia.
Offering a very low temperature co-efficient; the Panasonic modules still perform well on very hot days while the output of other panels may be significantly below their nameplate wattage.
Panasonic states out of the many thousands of HIT modules installed in Australia, none have failed or been subject to a warranty claim.
