Long-term performance of amorphous photovoltaic modules

This work aims to demonstrate the energy production of amorphous silicon devices through long-term monitoring. Some devices have a very high specific energy production while other does not accomplish this. The reasons for seasonal variations are investigated. Assuming that the short circuit current is mainly influenced by spectral changes allows degradation to be attributed to the fill factor. The seasonal variation of this is investigated in more detail, demonstrating differences between single and multi junction devices.