Possible transition of Japan’s power system with flexibility supply from distributed resources

In a transition to carbon neutral of a power system, the decline of traditional generation capacity in operation and the increase of variability and forecast error of photovoltaic (PV) and wind generation simultaneously cause a short of supply of balancing flexibility requirement. In the transition the best use of distributed energy resources (DER) such as PV, wind, demand responses (DR), and batteries are possibilities for a power system so as to secure the affordable and stable energy utilization. For the study on the future flexibility supply, authors review the latest situation of the renewable energy (RE) generation curtailment and the balancing flexibility market in Japan, and, using demand and supply analysis of 8760 hours by “MR”, analyse the benefits of balancing flexibility supply from both traditional generators and emerging DER for Japan’s power system in 2040. The results imply that it is crucial to be ready for the utilization of flexibilities from DER through two aspects: the first one is different technologies such as dedicated batteries and demand response with characteristics of different response time, energy limit (duration time) and certainty of control can share the requirements for balancing flexibility, The second is that the flexibility requirements can be rationalized and minimized.