2017 Volume 137 Issue 7 Pages 499-510
This study aims to quantitatively clarify the impact of large variable renewable energy (VRE) which is concentrated in some districts. Such districts will have difficulties to balance between power demand and supply, and keep the load frequency control (LFC) ability, and will be forced to curtail much VRE. Authors developed a simulation model to optimize generation mix and hourly operation of thermal and pumped hydro generation considering partial load efficiency, LFC supply and demand, and power transmission between districts. With this model, the authors obtained the following results on Japan's power system in 2030. (1) When VRE ratios to power system size are averaged, the VRE curtailment rates will much decrease. This way is difficult for wind power and other measures are required. (2) The curtailment rates can decrease a little by having some extra capacity of LNGCC though this is a very expensive way. (3) The capacity factors of LNGCC will be very low in some districts, and some incentives to hold LNGCC are required to use VRE stably.