Australian scientists announce solar energy record

Solar cells have set new records in the past week, heading towards converting half the sunlight hitting them into electricity.

ABC Environment, 8 Dec 2014

Solar cell efficiency is nearing 50 per cent. Credit: Lena Anderson (iStockphoto)

AUSTRALIAN SCIENTISTS have set a new record in increasing the efficiency of solar panels, which they hope could eventually lead to cheaper sources of renewable energy.

In what the University of New South Wales described as a world first, the researchers were able to convert more than 40 per cent of sunlight hitting the panels into electricity.

"This is the highest efficiency ever reported for sunlight conversion into electricity," UNSW Professor Martin Green said in a statement.

"We used commercial solar cells, but in a new way, so these efficiency improvements are readily accessible to the solar industry," added Dr Mark Keevers, the UNSW solar scientist who managed the project.

While traditional methods use a single solar cell, which limits the conversion of sunlight to electricity to about 33 per cent, the newer technology splits the sunlight across four different cells, each optimised for the fraction of the sunlight they receive, which boosts the efficiency level, Green said.

The four-way solar cells can be used at the centre of a field of mirrors which are arranged to concentrate the Sun's rays. Specialised filters shuttle heat away from where it would reduce the solar cells' efficiency and towards the solar cell that can best handle the heat.

The record efficiency level was achieved in tests in Sydney and replicated at the United States government's National Renewable Energy Laboratory, the university said.

Green is hopeful the technology can also eventually be used for solar panels mounted on people's roofs, which he said currently had a 15 to 18 per cent efficiency rate.

"The panels that you have on the roof of your home, at the moment they just have a single cell but eventually they'll have several different cells... and they'll be able to improve their efficiency to this kind of level," he said.

German efficiency

Meanwhile in Germany, scientists set a new record for solar cell efficiency in a laboratory setting, converting 46 per cent of light into electricity.

The scientists from the Fraunhofer Institute for Solar Energy Systems used a type of solar cell called a multi-junction cell, made of layers of semiconducting materials, with the record-setting cell being a four-junction cell. Each of its sub-cells converts precisely one quarter of the incoming light, including all the colours of the rainbow plus infrared light (wavelength between 300 and 1750 nm), into electricity. The light is concentrated using a kind of magnifying glass called a Fresnel lens.

The new record efficiency was measured at a concentration of 508 suns and has been confirmed by the Japanese AIST (National Institute of Advanced Industrial Science and Technology), one of the leading centres for independent verification of solar cell performance results under standard testing conditions

Jocelyne Wasselin, vice president solar cell product development for Soitec, a company which partnered with the scientists said: "We are very proud of this new world record. It... clearly indicates that we can demonstrate 50 per cent efficiency in the near future."

ABC/AFP

Related Article:

This Japanese woman can reduce the price of solar energy around the world