Sumitomo Electric Receives Third Order for Redox Flow Batteries to Support Kashiwazaki’s Decarbonization Efforts
Sumitomo Electric Industries, Ltd. has secured its third consecutive order for redox flow (RF) battery systems from Kashiwazaki IR Energy Co., Ltd., further advancing the city of Kashiwazaki’s goal to become a fully decarbonized community. This latest order reinforces the company’s role as a key contributor to Japan’s energy transition and sustainability goals.
Construction on the new battery installation commenced on July 10, marked by a traditional Shinto groundbreaking ceremony to pray for the safety of the workers and successful project execution. Attendees included representatives from Sumitomo Electric, Kashiwazaki IR Energy, local government officials, and other stakeholders, underlining the significance of the project not only for the companies involved but for the entire region.
Sumitomo Electric emphasized its ongoing commitment to safety, environmental responsibility, and smooth project management throughout the construction and installation phase. This installation is the third of its kind in the area and will be located at the Nishiyama Multipurpose Sports Park in Kashiwazaki City, Niigata Prefecture. The scheduled completion date for the new system is set for spring 2026.
The new order adds a further 8,000 kWh of energy storage capacity to the already operational RF battery systems in the city. With the completion of this third system, the total redox flow battery capacity installed in Kashiwazaki will reach 24,000 kWh. The two previously completed installations include one at the Natural Environment Purification Center, finalized in September 2024, and another at the former Hojo Minami Elementary School site, set for completion in March 2025. Each of these installations features a 1,000 kW system capable of storing and discharging power over an 8-hour period.
Kashiwazaki, historically a center for Japan’s petroleum and nuclear energy industries, is undergoing a strategic transformation. Recognizing the need to transition away from traditional energy sources, the city has embarked on a bold initiative to promote renewable energy and reduce its carbon footprint. Sumitomo Electric’s RF batteries play a pivotal role in enabling this shift by offering reliable energy storage and power management solutions that are safe, flame-retardant, recyclable, and environmentally friendly.
One of the critical challenges facing renewable energy adoption is the intermittency of power generation—particularly with sources like solar energy. Sumitomo Electric’s RF batteries help overcome this limitation by storing excess electricity generated during low-demand periods, such as midday when solar power production is at its peak. The stored energy is then discharged during high-demand periods, such as evening hours, ensuring a stable and efficient power supply.
Additionally, these battery systems are integrated into the wholesale electricity market. By leveraging a large-capacity battery system with 1,000 kW output over 8 hours, Kashiwazaki IR Energy can participate in electricity trading to further reduce energy costs while supporting grid stability. This dual capability of power smoothing and market participation exemplifies how battery storage systems can be used not only for resilience but also for economic optimization in modern energy infrastructure.
This initiative aligns with broader national and global efforts to reduce carbon emissions and promote sustainable development. Sumitomo Electric is proud to contribute to these efforts through its RF battery technology, which it continues to enhance and promote. The company aims to facilitate a localized energy ecosystem—where communities can generate, store, and consume renewable energy independently, reducing reliance on centralized power plants and fossil fuels.
The batteries also offer long operational life, low degradation rates, and high reusability, making them an ideal solution for municipalities and utilities looking to invest in future-ready infrastructure. As more local governments and energy providers seek to decarbonize their operations, Sumitomo Electric’s success in Kashiwazaki may serve as a model for similar deployments across Japan and internationally.
About Kashiwazaki IR Energy Co., Ltd.
Kashiwazaki IR Energy Co., Ltd. is a municipally affiliated power provider headquartered in Kashiwazaki City, Niigata Prefecture. The company is led by President Masahiro Sakurai, who also serves as the mayor of the city. It is jointly funded by the city government and eight private-sector partners. The company’s mission is to provide energy supply and utilization services that align with the city’s decarbonization and sustainability goals.
More information is available on their official Japanese website.
Overview of the Battery Installations
New Installation (Ordered in 2025)
- Location: Nishiyama Multipurpose Sports Park, Kashiwazaki City
- Product: Redox flow battery system (1,000 kW × 8 hours)
- Scheduled Completion: Spring 2026
Completed Installation #1
- Location: Natural Environment Purification Center, Kashiwazaki City
- Product: Redox flow battery system (1,000 kW × 8 hours)
- Completion Date: September 2024
Completed Installation #2
- Location: Former Hojo Minami Elementary School Site
- Product: Redox flow battery system (1,000 kW × 8 hours)
- Completion Date: March 2025
As Sumitomo Electric continues to expand its RF battery deployment, its collaboration with Kashiwazaki City is a clear testament to how technology and local governance can unite to create a cleaner, more resilient energy future.
