Large-scale penetration impact of photovoltaic power generation system on utility power plants

The large-scale penetration of photovoltaic power generation systems (PVSs) may cause both the positive and negative impact on the existing electric power system. For the detail impact assessment, the prediction of the future electricity load pattern as well as the power output pattern of PVSs is very important, while it would be very challenging issue. As a first step of the impact assessment, this study estimates the change in the load curve on the utility power plant due to the large-scale penetration of PVS, by using the past data of both the total electricity load on the utility power plants and the global horizontal irradiance observed at 40 sites in Japan. Then, this study discusses the impact on the existing electric power system due to the large-scale penetration of PVSs, focusing on the reduction in annual peak and minimum load, and the change in time-zone of daily peak load and daily minimum load.