摘要： Nominal values reported for PV Systems are measured at carefully-controlled test conditions. While being strictly standardized to achieve a good benchmarking capability for different, newly manufactured panels; these conditions hardly exist in real-life implementation sites. To add to the problem, highly varying climate, precipitation, scorching sun and freezing snow wear out these systems in the long run. Therefore, actual performance of any PV system is, inevitably, different than those reported under standard test conditions. In order to have a more accurate expectation of power generation over the lifetime of a system, it is important to know the impact of local conditions and the resilience of PV panels to them. To this end, several outdoor performance studies have been reported around the world and the literature is growing. This work reports the impact of Fukushima's weather, which is known to be windy in autumn and have heavy snowfall in the winter, on the installed PV systems. Also, numerous panels belonging to different PV technologies and manufacturers are installed side-by-side to compare the variation in their performances and, thus, benchmark their quality and resilience. To investigate possible impact of micro-climate, or local geographical conditions, two test sites in Fukushima Prefecture are utilized. Finally, a sample PV system calculation is presented to showcase the impacts of these findings on a PV system in planning and operation stages.