In-line manufactured CdTe thin film photovoltaic devices were evaluated for their performance with respect to power conversion efficiency and reliability (stability). A National Renewable Energy Laboratory (NREL) certified power conversion efficiency (77) Of 12.44% was measured for one CdTe device. A mean efficiency of 11.4% for 53 devices is shown. Results of reliability studies give a conservative estimate of -1% relative degradation per year in efficiency over a 20-year lifetime for these CdTe devices.