Through this project, 55 modules of 7 different types were measured and analysed in detail by the SPF mobile installation. 25 of them operated for 5 years at 1800 meters above sea level, the others have operated for about 5 years on the swiss plateau. The purpose of the project was to determine whether severe weather conditions and regular operation above nominal power have degraded the modules in the Alps significantly more than in similar installations at low altitude. On the contrary, it appears that the modules affixed to the roof, and therefore less ventilated, suffered on average more degradation than the alpine modules. The photovoltaic modules have endured the alpine conditions very well, which is encouraging for future deployment.