There are many companies in the solar power business that want to make themselves a name, but only few manage to innovate something indeed useful. This time I think Quantasol, a UK company has something worth looking at – very efficient GaAs-based solar cells accustomed to your location.
GaAs cells are much more expensive than classic silicon solar cells, and that’s the main reason they have only been used in space installations so far. The space, though, has uniform lighting conditions which you’ll never find down here on the ground. Our atmosphere filters the light, and so it varies from one place to another on Earth’s surface, also counting in atmospheric conditions.
To tune their new solar cells to particular lighting conditions, Quantasol added indium gallium arsenide (InGaAs) in nanometer-thick layers, called quantum wells. These quantum wells behave like a filter and an amplifier, in the way that they absorb frequencies that are very specific to the area they are used in. With these cells, you’ll only have the promised 28.3% efficiency if you’re in UK, for example, and you’ll need another customized type for using in Brazil.
Also, the 28.3% efficiency will be obtained when exposed to light 500 times stronger than normal sunlight, which is easily obtainable with cheap lenses and mirrors. These figures have been certified by the Fraunhofer Institute of Solar Energy in Germany.
“The commercial market doesn’t just want high efficiency, they want the device to be optimised to the environment,” says Kevin Arthur, Quantasol CEO. “In the past we measured performance in dollars per watt. Now it’s cents per kilowatt-hour that’s more important.“