Solar power could become much cheaper thanks to a record-breaking technology partly developed by a Cardiff-based company.
IQE has been working with an American partner to produce highly efficient multi-junction solar energy cells for the concentrated photovoltaic (CPV) market.
The technology is the same as has been used to power satellites and is around three times more efficient than normal solar panels at converting sunlight into electricity.
Cells incorporating IQE-made wafers have recently been certified by America’s National Renewable Energy Laboratory (NREL) as having an efficiency of 44.1%, beating the previous 44% record set last October by its California-based partner Solar Junction.
This compares to a typical 15% efficiency rating for standard silicon-based solar panels.
Besides their efficiency, multi-junction cells also have the advantage of being smaller than the silicon-based cells used in traditional photovoltaic panels.
Instead of using a large area of silicon to collect the light, the system uses cheap Perspex lenses which concentrate the light, and the panels (or modules as they are termed) are mounted on large units 60 feet across, which track the sun all day long.
The system is most likely to be of benefit in large scale solar power stations in countries where there is a lot of direct sunlight, but could eventually be used for smaller scale installations in less sunny countries.
IQE has secured a seven-year exclusive agreement to manufacture all the wafers used by Solar Junction, one of the world’s leading players in this technology.
A recent independent industry report said that the target market for CPV is expected to reach more than 5GW (gigawatts) over the next few years, with more than 750MW (megawatts) to be installed by 2015.
The IQE-Solar Junction units will initially be deployed in a number of installations under development in several southern European countries, including Greece, Turkey, Portugal, Spain and France.
Other installations are planned in North African and Middle Eastern countries.
Further afield, similar installations are planned or under development in South Africa, China, India, Australia, Japan, the southwestern US, Mexico, Chile and Peru.
Most of these installations are for significant power plants to feed into grid applications, but smaller commercial scale rooftop systems are also under development.
One advantage is that the systems are modular and can be located at the point of use – for example, just outside a town or city – reducing the requirements for ugly pylons and saving power since the transmission losses are greatly reduced.
IQE’s recent efficiency record follows the qualification of its wafers for high volume production.
Dr Drew Nelson, IQE chief executive, said: “Following our recent announcement of full qualification of our high volume 4-inch and 6-inch CPV technology, surpassing Solar Junction’s previous cell efficiency record is a massive achievement.
“Improvements in CPV cell efficiencies translate to highly significant overall cost reduction in terms of installation and energy generation in utility scale solar farms. The fact that this has been achieved on production qualified platforms is a major milestone.
“Furthermore, the transfer of wafer production to IQE’s manufacturing tools enables the Solar Junction team to focus on further improving efficiencies on lattice-matched, multi-junction CPV solar cells using a combination of their unique dilute nitride technology, combined with pre-existing IQE intellectual property.
“This will facilitate seamless technology transfer into high volume manufacture of ultra efficient CPV cells as the conversion efficiency improves further.”
Vijit Sabnis, CEO at Solar Junction, said: “Breaking a world record is a major achievement, but improving on our most recent record using high-volume production equipment produced in conjunction with our manufacturing partner IQE, and Solar Junction’s fabrication line in Sunnyvale, California, is dramatically more significant.
“This result is a testament to our close partnership with IQE, Solar Junction’s dilute nitride technology and our exceptional team. We continue to be the benchmark for multi-junction solar cell production efficiency to assist our customers in driving CPV costs down.”