Evonik (Essen / Germany; www.evonik.com) has developed two “innovative solutions” for concentrating photovoltaics (CPV), a promising new cost-efficient technology used for converting solar energy into electricity. Its “Plexiglas” PMMA is used in the structured “Fresnel” primary lenses, which focus the light and direct it through secondary lenses made of Evonik’s “Savosil” (www.savosil.com) silica-based materials. The secondary lenses make direct contact with the solar cells, thereby further increasing the yield.

The German group says the micro to macro structures in the primary lenses concentrate sunlight by a factor of up to 1,000. Light that would otherwise be dispersed over several square metres is confined to a fraction of this surface area and converted into electricity with high efficiency. The secondary lenses are attached directly to the solar cells, behind the primary lenses.

Evonik began positioning itself on the solar lenses market with the two new innovations earlier this year; however, its PMMA products, including sheet, moulding compounds, films and tubes, have been used in solar applications since 2009. Savosil is already being used in light-emitting diodes (LEDs). The group is now jointly offering the Plexiglas and Savosil products as a systems supplier, says Daniele Fregonese, marketing director technology solutions at Evonik.

The primary lenses are produced in collaboration with US company 10X Technology (Libertyville, Illinois; www.10xtechnology.com), the secondary lenses are manufactured in Taiwan by Evonik Cristal Materials Corporation, a 52:48 joint venture of Evonik and Cristal Materials Corp (Taipei).