Transparent solar could meet almost half of US energy needs

Transparent solar materials could harvest enough power to meet almost half of the US’s energy demand, according to new research in Nature Energy.

The researchers mapped the extent of glass surface across the US and found that fitted with transparent solar technologies, 40 per cent of the US’s electricity demand could be met – about the same potential as rooftop solar.

Led by engineering researchers at Michigan State University, the report said innovative and cost-effective renewable energy technologies could help decrease global reliance on fossil fuels.

“Highly transparent solar cells represent the wave of the future for new solar applications,” MSU associate professor of chemical engineering and materials science Richard Lunt said.

“We analysed their potential and show that by harvesting only invisible light, these devices can provide a similar electricity-generation potential as rooftop solar while providing additional functionality to enhance the efficiency of buildings, automobiles and mobile electronics.”

Dr Lunt and his colleagues developed a transparent luminescent solar concentrator that uses organic molecules to absorb invisible wavelengths of sunlight, “tuning” these materials to pick up only ultraviolet and the near-infrared wavelengths.

They can be placed on buildings, car windows and even cell phones, transforming any clear surface into a solar harvesting factory without affecting the function or aesthetics.

The report said there was an estimated five to seven billion square metres of glass surface in the US, but only about 1.5 per cent of electricity was produced by solar power.

Transparent solar technology could open the door to using vast areas of previously inaccessible clear surface for energy generation, increasing the global use of solar power and supplying close to 100 per cent of US energy demand if coupled with rooftop solar and improved energy storage, Dr Lunt said.

He added that transparent solar technologies have only reached about a third of their overall efficiency potential. They have about five per cent efficiency levels while traditional solar panels record about 15 to 18 per cent.

See-through solar will never reach the potential of its rooftop equivalents, but further research can bring them up to par to and apply them to additional surface areas, Dr Lunt said.

Similar technologies have been developed in Australia to increase solar power usage.

A team of researchers in Perth developed a similar technology – the world’s first clear energy-harvesting glass – that has already been used to build a self-sufficient bus shelter in Melbourne, and might make its way to a Singapore airport.

Researchers at the Australian National University also set a record when they achieved 26 per cent efficiency in semi-transparent perovskite solar cells, a low-cost alternative for silicon cells.

Once they reach the stability of their silicon cell equivalent, they can be used for over 20 years.