This paper investigates the risks stemming from landslides and floods for the existing solar photovoltaic (PV) power plants in Japan. Dominated by mountainous terrain, Japan has limited flat land area that is suitable for solar photovoltaic (PV) power generation and a high risk of natural disasters. There is a possibility that some of its newly built solar power plants are located in areas where landslides and floods are likely to occur. Therefore, it is important to study the locations for solar PV from the perspective of disaster risk management. Previous studies have reported a number of incidents where solar PV installations were damaged as a result of natural disasters. The researchers compare the geographical data of disaster risks in Japan with the location data of solar PV power plants to investigate the number of solar PV power plants located in disaster risk areas.
The study counts the total number of the solar power plants in Japan as 9,250 points. Among them, 782 points were found to overlap with the sediment-related disaster hazard areas as a whole, which is around 8.5% of the total solar PV locations in Japan. Also, among all the solar PV locations, the number of points overlapping the flood and inundation hazard areas was 846. This is about 9.1% of the total number. The results not only show that a significant number of solar power plants are located in the disaster risk areas, but also contribute to the discussion on future potential sites for solar PV installations.