Dwindling oil reserves, global warming and an interest in living a greener lifestyle have been generating a wave of interest and support in renewable energy in recent years and consequently a slew of solar energy innovations have been hitting the headlines. One of the holy grails of solar cell production is efficiency and records relating to the amount of sunlight converted into energy by a cell have tumbled every couple of months.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE in Germany recently announced the achievement of a record efficiency of 41.1% for the conversion of sunlight into electricity. Currently, solar panels generally available on the market have an efficiency of between 12 and 18 percent. The result was achieved with a sunlight concentration factor of 454 and even at a higher sunlight concentration of 880, an efficiency of 40.4% was measured.
The new solar cells developed by the Fraunhofer team are comprised of thin layers of gallium indium phosphide, gallium indium arsenide on a germanium substrate..
In contrast to conventional solar cells, the semiconductors in these cells do not have the same distance between the atoms in a crystalline structure which has made it difficult to grow the multiple semiconductor layers with a high crystal quality in conventional technology.
The high efficiency multi-junction solar cells will be used in concentrating photovoltaic systems for solar farms in countries with good levels of direct solar radiation.
According to Dr. Andreas Bett, Department Head at Fraunhofer ISE, the high efficiencies of the new solar cells are the most effective way to reduce the electricity generation costs for concentrating PV systems and with the new efficiency results, the concentrated solar energy sector has taken a big step towards reaching the goal of being cost competitive with conventional methods of electricity generation.