Anti-aging elixir for solar cells

Producing solar cells and modules is expensive. Therefore, it is essential that modules last as long as possible, at least 25 years.

Engineering teams around the world are now investigating new technologies and production methods to make cells and modules cheaper, more efficient, more durable and reliable.

Researchers from the Fraunhofer Center for Sustainable Energy Systems and Dow Corning Corporation said they are working on materials to protect solar cells from environmental influences. Silicone appears as one of the most promising materials.

So far, photovoltaics modules have been encapsulated with silicones but they were not commonly used for laminating solar modules, researchers said. Today, most manufacturers of photovoltaic cells use ethylene-vinyl acetate, or EVA.

As part of their research, Fraunhofer and Dow Corning Corp. scientists said they coated photovoltaic cells with liquid silicone and observed that when the silicone hardens, it encases the cells. The electronic components then have optimal protection.

The experts at CSE constructed prototypes from the silicone-laminated cells, and tested these photovoltaic modules in a climate chamber at low temperatures and under cyclic loads. The module performance was then tested with a light flasher.

In parallel, researchers said they used electro-luminescence-imaging for the detection of micro cracks. A comparison of the results with those of conventional solar modules proved that silicone-encased photovoltaic modules are more resistant to cyclic loading of the type modules experience in strong winds, in particular at a frosty minus 40 degrees Celsius.

Eventually, researchers from Fraunhofer and Dow Corning Corp. claimed they have demonstrated 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. With this technology it is possible, for instance, to make modules with thin Si cells more robust.