Domenico Chianese, Head of Photovoltaic and Electrical System Group, SUPSI talks about the paramount importance of PV materials, whose quality should not be compromised for the long-term durability and performance of solar modules. SUPSI in Canobbio, Switzerland is host to the first grid-connected PV intallation in Europe. The plant was built in 1982 using mono crystalline silicon modules from Arco Solar, with Tedlar®/metal foil/Tedlar® backsheets. The 10 kW plant is still in operation today, with 97% of its initial power.