Study on Surplus Electricity under Massive Integration of Intermittent Renewable Energy Sources

In order to address climate change and energy security issues, intermittent renewable energy sources such as solar photovoltaic (PV) and wind power are gaining considerable attention. However, due to their variability and surplus electricity, the expansion of these renewables is an important challenge for power grid management. Various countermeasures such as rechargeable batteries, suppression, and back-up generators, are considered necessary for the physical integration of intermittent renewables to create an efficient and reliable power generation mix. In this context, we developed a high time-resolution optimal power generation mix model to quantitatively assess the amount of surplus electricity available under the large-scale introduction of PV and wind power in the Hokkaido region of Japan and the potential roles for the countermeasures mentioned above. The main feature of the model is the detailed time resolution at 10 min through a year. This allows us to investigate the impact of variation in various short-cycle renewables on surplus electricity and the deployment of rechargeable batteries. The simulation results suggest that if a proportion of PV and wind power expands more than around 10% and 20% of total demand respectively or if the sum of the proportion of PV and wind power exceeds 20%, the need for suppression grows rapidly. The results also suggest that rechargeable batteries are more economically compatible with PV than wind power is. (C). 2017 Wiley Periodicals, Inc. Published online in Wiley Online Library (wileyonlinelibrary.com).