Silicone promises to extend solar cells’ lives

Coating photo-voltaic (PV) cells with liquid silicone could yield more robust and sustainable solar cells at a fraction of the cost of traditional ones.

Solar panels deliver power without risk to the environment and climate, but their durability comes at a price.

For solar panels to exceed life spans of 25 years, scientists must investigate various types of protective coatings to shield the solar cells from harmful environmental influences.

To help protect the fragile silicon solar cells within a panel, manufacturers have used expensive ethylene-vinyl acetate coatings.

Now, researchers at the Fraunhofer Center for Sustainable Energy Systems and Dow Corning Corp. are investigating a cheaper alternative material: silicone.

In this mechanical test stand, a researcher examines the quality of silicone-encased solar modules. Coating solar cells with liquid silicone strengthens them and makes them more sustainable at a much lower cost than traditional coatings. ©Fraunhofer CSE.

Silicone has been used to encapsulate PV modules, but until now, it has not been widely used for laminating solar modules.

Fraunhofer scientists prepared prototypes of silicone-laminated cells and tested them in a climate chamber at low temperatures under cyclic loads. The cells were then tested with a light flasher and electroluminescence imaging to detect microcracks.

In comparison with traditional solar modules, the silicone-encased PV modules were more resistant to cyclic loading of the type that panels experience in strong winds; in particular, at extremely low temperatures of -40 °C.

“The study results demonstrate that silicone lamination is well suited for certain applications because the silicone protects the fragile components on the inside well and, moreover, withstands severe temperature fluctuations,” said project manager Rafal Mickiewicz.

The findings, which were published at the 26th European Photovoltaics Solar Energy Conference, could help improve understanding of material requirements for solar modules, particularly with regard to sustainability and output, said Andy Goodwin, global science and technology manager for Dow Corning Solar Solutions.