Japan: Tesla to supply 548MWh BESS, Sumitomo Electric deploying 12.5MWh flow battery

February 5, 2025
LinkedIn
Twitter
Reddit
Facebook
Email

Tesla and Sumitomo Electric have both been selected to supply energy storage projects in Japan. Tesla will supply Megapacks for a BESS project while Sumitomo will deploy a 12MWh vanadium flow battery.

Financial services firm Orix Corporation selected Tesla to supply 134MW/548MWh of BESS to the Maibara Koto Power Storage Plant project in the city of Maibara, Shiga Prefecture. Tesla will provide Megapacks for the 4.1-hour duration battery energy storage system (BESS) project, which is set to come online in 2026.

The project won one of the largest successful contracts in Japan’s low-carbon capacity auctions of 2023, auctions which one consultancy said would significantly increase the business case for energy storage in Japan with 1.67GW of BESS winning contracts.

It is not Orix’s first BESS project in Japan, having in 2022 announced the deployment of a 113MWh BESS in partnership with utility Kansai Electric for operation in 2024.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

The 2023 auctions appear to have increased interest and activity in Japan’s energy storage market, from BESS investment platforms from abroad including Eku Energy and Gore Street as well as local utilities and independent power producers (IPPs).

See all recent Energy-Storage.news coverage of Japan here. Recent Premium pieces include an interview with developer Gurin Energy on its 2GWh project and a panel discussion roundup from Energy Storage Summit Asia 2024, held in Singapore.

Sumitomo Electric 12.5MWh flow battery project on Oki Islands

In concurrent news, technology provider Sumitomo Electric will provide a 4MW/12.5MWh redox flow battery system for a project on the Oki Islands, off the coast about a day’s drive west of Maibara.

The project in Ama Town is an initiative from utility Chugoku Electric Power Transmission & Distribution Co in partnership with local authorities and a company called ‘como-gomo.company’, Sumitomo said.

It didn’t say when the project would be built, but said it will benefit from a subsidy under the Ministry of the Environment’s “Facility Introduction Support Project for Mainstreaming Renewable Energy in Remote Islands.”

Sumitomo Electric also didn’t say exactly what kind of electrolyte-based flow battery it would deploy, but the company has typically used vanadium redox flow battery (VRFB) technology. The project will contribute to carbon neutrality and resilience in the face of natural disasters in the Oki Islands, it said. It will involve building a power network that will enable microgrid operation during emergencies.

Sumitomo Electric has previously deployed 8MWh and 51MWh VRFB projects in Japan.

Read Next

November 27, 2025
The Western Australian government has launched the first stage of an Expression of Interest (EOI) process for a 50MW/500MWh vanadium flow battery energy storage system (VBESS) in Kalgoorlie.
November 20, 2025
From the US, Maxwell Technologies is acquired for its third time, by Clarios, Fullmark Energy completes a tax credit transfer, and OATI partners with Colville Tribes on microgrid solutions.
November 18, 2025
The quarterly financial results of US non-lithium battery storage startups ESS Inc and Eos highlight their commercialisation strategies.
November 12, 2025
Although vertically integrated ESS-cell suppliers retain more control over their supply chain, system integrators’ flexibility may help them in the medium-term, writes Solar Media Market Research analyst Charlotte Gisbourne.
November 7, 2025
Developer-operator Plus Power has secured US$160 million in tax equity investments from Morgan Stanley for two battery energy storage system (BESS) projects in Massachusetts and Maine, US.