It has always been a concern to the investors and financers on the life expectancy of the PV modules, as every PV module has a degradatyion rate when exposed to the solar radiations. The module degradation rate ranges from 0.1-5% on annual basis, however the module degradation rate vary with respect to technologies, age, manufacturers, and geographic locations. In case of crystalline technologies, there is a long term data for devades is available to back up the module degradation rate, however in case of thin film technology, degradation rate data is not as plentiful.
THe NREL study conducted on the degradation of PV modules show a significant improvement for thin-film technologies during the past decade
NREL has also conducted the test bed performance of CIGS modules for assessing the degradation rates. The study found that after 5 years of outdoor exposure shows a very stable performnance of CIGS modules. Although the long term data are yet to be collected with the time, however the preliminary trends indicates that the new technological devgelopment in module manujfacturing has led to a great decline in the degradation rates of the PV modules.