Solar-powered paint

Technology that allows solar cells to be painted onto the flexible surfaces commonly used for cladding buildings is being developed by researchers at Swansea University, in Britain.

“We have been collaborating with the steel industry for decades, but have tended to focus our attention on improving the long-term durability and corrosion resistance of the steel. We haven’t really paid much attention to how we can make the outside steel capable of doing something other than looking good,” said Dr Dave Worsley, a Reader in the Materials Research Centre at the University’s School of Engineering. 

“One of our engineering doctorate students was researching how sunlight interacts with paint and degrades it, which led to us developing a new photovoltaic method of capturing solar energy.” 

The cell generation efficiency is around 4–5% so how much electricity the cells generate depends on lighting conditions. The painted panels can be connected together to harness power. 

Paint is applied to steel when it is passed through rollers during manufacture, and researchers hope that this system can be used to build up layers of solar cell.  

The aim is to produce cells that can be painted onto a flexible steel surface at a rate of 30–40 m² a minute. 

“Corus Colours produces around 100 million square metres of steel building cladding a year. If this was treated with the photovoltaic material and assuming a conservative 5% energy conversion rate, then we could be looking at generating 4500 GW of electricity through the cells annually. That’s the equivalent output of roughly 50 wind farms,” Worsley said.  

Worsley will be working closely with Corus to research practical, cost-efficient methods of mounting the system on steel structures, with a view to eventual commercialisation.

Market development is an unknown, according to Worsley, but it is unlikely to be within the next three years.

Unlike conventional solar cells, the materials being developed at Swansea are more efficient at capturing low light radiation, making the cells better suited to the British climate. 

Worsley is unsure how the cells would cope in a harsher Australian environment but noted that obviously for each environment, specific durability issues would have to be tested and the dye-sensitised cells could be attacked by excessive sunlight. However, he believes this can be screened out.

“Corus is working with Australian company Dyesol, an expert in dye-sensitised solar cells,” Worsely said.

A research grant from the Welsh Assembly’s Energy Research Centre enabled Worsley to work with Corus to investigate the feasibility of developing an efficient solar cell system that can be applied to steel building products.

The success of the study led to the award of a three-year project by the Engineering and Physical Sciences Research Council.

Swansea University is now leading a partnership with Bangor University, the University of Bath and Imperial College London to develop the photovoltaic materials into commercial systems.