Australasian Science: Australia's authority on science since 1938

World Record for Solar Energy Efficiency

Solar researchers at the University of NSW have converted more than 40% of the sunlight hitting a solar system into electricity, the highest efficiency ever reported.

The world-beating efficiency was achieved in outdoor tests in Sydney before being independently confirmed by the National Renewable Energy Laboratory at its outdoor test facility in the United States.

“This is the highest efficiency ever reported for sunlight conversion into electricity,” said Prof Martin Green of the Australian Centre for Advanced Photovoltaics.

“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 of UNSW, who managed the project.

“The new results are based on the use of focused sunlight, and are particularly relevant to photovoltaic power towers being developed in Australia,” Green said.

A key part of the prototype’s design is the use of a custom optical bandpass filter, which captures sunlight that is normally wasted by commercial solar cells on towers and converts it to electricity at a higher efficiency than the solar cells themselves ever could. Such filters reflect particular wavelengths of light while transmitting others.

The 40% efficiency achievement is outlined in a paper in Progress in Photovoltaics.

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In a separate development published in Advanced Materials, researchers at Swinburne University of Technology’s Centre for Micro-Photonics have developed a carbon nanofibre that improves the efficiency of silicon-based solar cells.

“This nanofibre exhibits superior light-scattering properties, ultralow absorption loss and high electrical conductivity,” said Dr Xi Chen. “By integrating the nanofibres with solar cells we have demonstrated an efficiency boost of 3.8%.”

This result is almost five times greater than the current record, creating one of the highest-performing silicon thin-film solar cells.

The low-cost and scalable nature of the nanofibres have a range of applications in solar cells, photodetectors, supercapacitors and biosensors.