Eku Energy plans to build a 150MW/600MWh grid-scale battery storage facility in Kasaoka City, Okayama Prefecture, by 2030, the company announced on April 30, 2025.
The four-hour Eshi BESS is the largest by derated power capacity (119MW) among the 21 three-to-six-hour battery storage projects awarded in Japan’s second long-term decarbonization auction. With the contract secured in the auction, “Eku Energy will receive payment from OCCTO towards the initial cost of constructing the BESS and running costs for the multi-year power supply,” the company said.
“Securing the LTDA for our Eshi BESS adds further high-quality long term contracted revenue to our Japan and global portfolio with our first LTDA project in Japan diversifying our revenue mix,” said Eku Energy’s CEO Daniel Burrows.
The grid-scale storage project is Eku Energy’s second in Japan following the 30MW/120MWh Hirohara BESS in Miyazaki Prefecture, which the company plans to commission in July 2026 and operate under a 20-year tolling agreement with Tokyo Gas.
It is also one of the largest BESS projects being developed in Japan, where the majority of projects are high-voltage and extra high-voltage projects are typically 50MW or smaller.
