ENERES Co., Ltd.
National University Corporation Hokkaido University

ENERES Co., Ltd. and Hokkaido University Graduate School/Faculty of Information Science and Technology will jointly conduct research in FY2024 on utilizing distributed energy resources (DER) to mitigate congestion in local distribution systems.

■Research Background based on Challenges
As renewable energy becomes the main power source, frequent “renewable energy output control” has become a problem, where renewable energy output must be suppressed due to grid congestion when power demand cannot keep up with weather-dependent renewable generation output. While current grid congestion is caused by imbalances in supply and demand across the “entire grid,” local congestion is expected to occur from “local distribution systems” (see figure) near solar power installation sites in the future.

Flexibly adjusting generation and demand amounts to mitigate congestion in local distribution systems is called “local flexibility.” Building schemes to utilize DER such as electric vehicles (EVs), which are expected to increase in the future, for this local flexibility is believed to contribute not only to avoiding renewable energy output control but also to avoiding future reinforcement of power transmission and distribution facilities centered on local distribution systems.

■Research Content
This research will analyze “when and where local congestion and renewable energy surplus may occur” in local distribution systems. Based on this, it will verify methods to mitigate local distribution system congestion by having DER such as EVs absorb renewable energy surplus in that area. It is also planned to conduct surveys on business schemes and economic efficiency. To implement the research, ENERES will utilize technology to improve predictability of congestion in local distribution systems and ‘group management/control’ technology cultivated through aggregation demonstrations, while Hokkaido University will utilize various power and energy system technologies including grid congestion analysis cultivated through previous research.

■Knowledge of ENERES and Hokkaido University
Through METI’s demonstration projects “Renewable Energy Aggregation Demonstration Project” and “DER Aggregation Demonstration Project” (subsidy execution organization: Sustainable open Innovation Initiative) in FY2021-23, ENERES improved renewable energy generation prediction accuracy and demonstrated that sufficient control accuracy could be achieved through “group management/control” that aggregates and controls low-voltage resources as resource groups. Applying this “group management/control” to spatially distributed low-voltage resources and controlling only resources at grid congestion points enables more effective local flexibility functionality.
Hokkaido University researches and develops power and energy system operation, control, planning, and analysis technologies, and in recent years has particularly focused on creating new power systems coordinated with variable renewable energy generation.
ENERES and Hokkaido University will continue to strengthen industry-government-academia collaboration while taking on the challenge of building new power systems that contribute to making renewable energy the main power source and realizing a decarbonized society.