Development and Field Demonstration of the Iida Microgrid on Actual Power System

The realization of a decarbonized and resilient society requires effective utilization of distributed energy resources and autonomous power systems. In Japan, where natural disasters such as typhoons and earthquakes may sometimes cause prolonged power outages, enhancing the resilience of local electricity supply is a critical challenge. This paper presents the development, implementation, and field demonstration of the Iida Microgrid constructed on an actual distribution system in Iida City, Nagano Prefecture, Japan. The microgrid was designed to promote local production and consumption of renewable energy during normal operation while ensuring a stable power supply through islanding operation during emergencies. The system integrates photovoltaic generation, a battery energy storage system, and a cloud‐based energy management system enabling forecasting, scheduling, and coordinated control of distributed resources. Operational results under grid‐connected conditions demonstrate reduced CO 2 emissions through increased local consumption of renewable energy. Prior to the field demonstration, simulation studies were conducted to evaluate protection performance, power quality, and system stability during islanding operation. Furthermore, islanding operation tests on the actual grid verified the system capability to safely and stably supply electricity to local loads in the event of upstream outages. These results confirm the feasibility and effectiveness of microgrids for regional decarbonization and disaster resilience. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.