Renewables integration grid study for the 2030 Japanese power system

This study reports the methodology and results of a renewables (REs) integration grid study for the 2030 Japanese power system. In light of the Japanese energy policy outlook for 2030, two scenarios were compared: the government's target scenario with 22–24% RE penetration (64 GW solar and 10 GW wind), and a scenario with higher RE penetration (100 GW solar and 36 GW wind). The impact of these two RE integration scenarios on the grid in terms of frequency stability and power flows were simulated and compared. The evaluation outcomes showed that a RE penetration more ambitious than the government's plan can be achieved without compromising the evaluated elements of grid security and without additional technical measures in situations with at least up to 62% variable REs, i.e. wind and solar, instantaneous penetration in western Japan and at least up to 36% in eastern Japan. Furthermore, technical solutions like soliciting fast frequency response from solar and wind power plants, and setting a system non-synchronous penetration limit for grid management can be applied to improve grid security for higher RE penetrations.