Abstract
A power system demand analysis toward a year of 2030 has been performed on the basis of Japanese government strategy formulated in 2012. We have quantified the effect of an introduction of a large amount of renewable energy over power supply operation by incorporating an evaluation of frequency control capacity into our optimization results. We reveal the critical shortage of the frequency control capacity available in whole power system, which is caused by the penetration of renewable energy. We also discuss the measures to resolve this issue from the practical viewpoint of power supply operation.