Researchers at the University of New South Wales have converted over 40% of the sunlight hitting a solar system into electricity – the highest efficiency ever reported.

The world record efficiency was achieved in tests in Sydney and, then, independently confirmed by the US National Renewable Energy Laboratory.

A key part of the design is the use of a custom optical bandpass filter, which reflects particular wavelengths of light while transmitting others, to capture sunlight that is normally wasted by commercial solar cells on towers.

Professor Martin Green, Director of the Australian Centre for Advanced Photovoltaics, said that “The new results are based on the use of focused sunlight, and are particularly relevant to photovoltaic power towers being developed in Australia”.

Power towers are being developed by the Australian company, RayGen Resources, which provided design and technical support for the high efficiency prototype.

The work was funded by the Australian Renewable Energy Agency and supported by the Australia–US Institute for Advanced Photovoltaics.