This paper investigates the capability of satellite remote sensing to monitor the performance of ground-based photovoltaic (PV) arrays. A comparison between the actual output of PV power plants and satellite-simulated output estimates at six climatically distinct locations is presented. The paper shows evidence that the satellite resource is an effective means of monitoring the performance of PV systems and of detecting potential problems with these systems, Large problems may be detected through the observation of sizeable monthly differences (>25%) between satellite-predicted and actual system output. Smaller problems may also be identified through an analysis of the evolution of these differences over time.