III-V cells in the Outback as Spectrolab wins order
Remote communities lying deep in the Australian Outback are becoming the first in the world to use an electricity supply generated by triple-junction solar cells.
In a multi-million pound deal to support the deployment of new solar power stations, Spectrolab, the Boeing subsidiary that specializes in multi-junction cells based on compound semiconductors and germanium, is set to deliver half a million solar cell assemblies to the Australian firm Solar Systems.
The power stations being built by Solar Systems are expected to generate more than 11 MW of electricity in total - enough to power 3500 homes.
The two companies have been partners for some time, and in April this year they developed a 35 kW solar generator. In May, one of its concentrator systems began operating in Hermannsburg "“ deep in Australia's Northern Territory and 120 km from Alice Springs, the nearest town of any size.
Both Solar Systems and Spectrolab are excited about the potential of the technology, and according to Solar Systems managing director Dave Holland the latest supply deal could be just the start of what may become a more extensive agreement:
"The breakthrough shows the potential for concentrating photovoltaics to dramatically change the economics of solar power," said Holland. "We expect this to be the first commercial phase of a very large and valuable relationship."
Although crystalline silicon photovoltaics is far more advanced in commercial terms, it is much less efficient than the compound semiconductor approach. In addition, silicon is not compatible with concentrator systems, meaning that a far greater area of semiconductor die is required for large-scale solar "farm" applications.
The relative shortage of the necessary silicon material has pushed up the price of this technology in recent years, and strengthened the economic case for concentrator systems based on a much smaller area of triple-junction die.
The concentrators deployed by Solar Systems use a set of curved mirrors that direct a concentrated beam of sunlight onto the triple-junction material. A tracker system follows the path of the Sun throughout the day, maximizing the collection of direct sunlight.
In the remote communities that Solar Systems is targeting, the solar power stations provide energy during the day before diesel generators take over at night.
