Solar power is still considered economically non-viable in comparison to energy derived from fossil fuels. According to Christian Hoepfner Scientific Director of the Fraunhofer Center for Sustainable Energy Systems (CSE) in Cambridge, United States, the market penetration of renewable energy on a global scale is possible only by making the production cheaper.
In this mechanical test stand the researcher examines the quality of silicone-encased solar modules. Credit: © Fraunhofer CSE
With production of solar cells and modules continuing to be a costly affair and with difficulties in arbitrarily enhancing efficiency of solar modules, engineers worldwide are attempting to devise new technologies and processes to make solar modules economical and robust.
Silicone, a unique material that can neither be categorized as an organic polymer nor an inorganic crystal, shows promise in developing solar modules with desirable characteristics. Silicones have been employed in laminating PV modules. But they have not been used for encasing solar modules. Ethylene-vinyl acetate or EVA is the protective lamination adopted by most manufacturers for photovoltaic cells.
Researchers from Fraunhofer and Dow Corning, the silicone manufacturer conducted a joint study to determine if silicone can replace EVA. The photovoltaic cells were coated with liquid silicone which later hardened to form a protective coating on the cells. The silicone-coated cells were then used to build prototypes of photovoltaic modules and were tested under cyclic loads in a climate chamber at low temperatures. The team used a light flasher to assess module performance and employed electro-luminescence-imaging to detect micro cracks. The silicone encased modules were found to exhibit better resistance than conventional solar modules to cyclic loading caused by strong winds at temperatures of minus 40°C. The new technology is envisaged to facilitate production of solar modules with thin and robust silicon cells.