A Tesla-powered battery energy storage system has begun commercial operations in Sapporo City, Hokkaido, Japan. The 50 MW/104 MWh Helios project, developed by Manoa Energy, uses Tesla's Megapack 2XL batteries to support Japan's grid. It operates as a merchant asset in wholesale, balancing, and capacity markets.
Manoa Energy announced the start of commercial operations for its Helios Battery Energy Storage System (BESS) on December 1, 2025, in Sapporo City, Hokkaido. The facility features 50 MW of power and 104 MWh of storage capacity, equipped with Tesla's Megapack 2XL utility-grade batteries. Construction began in April 2024, with engineering, procurement, and construction handled by HOKKAIDENKO Corporation. The project was developed in partnership with Brawn and HD Renewable Energy Japan.
Reports on the project's cost vary: one source estimates it at around $50 million, while others cite approximately $30 million. It marks the first standalone Extra High Voltage BESS asset for parent company Brawn and operates as a 100% merchant facility, participating directly in Japan's wholesale, balancing, and capacity markets without power purchase agreements.
Hokkaido's geographical isolation from Japan's main grid creates challenges for renewable energy integration, including high curtailment rates—Japan recorded 1.88 gigawatt-hours of renewable curtailment in fiscal year 2023, much in regions like Hokkaido. The Helios system aims to stabilize supply from solar and wind sources.
"Successful completion of our first standalone Extra High Voltage BESS asset emphasizes our commitment to sustainable infrastructure investment in Japan," said Scott Reinhart, CEO of Brawn. "Brawn will continue to develop our additional 1GW pipeline of Extra High Voltage and High Voltage assets throughout Japan, for commercial operations between 2026 and 2030."
Dean Cooper, Head of Manoa Energy and COO of Brawn, added: "Japan’s energy storage sector is experiencing rapid acceleration, positioning Japan among the world’s most dynamic energy storage markets. Manoa Energy is excited to be part of Japan’s energy transition momentum, as the country emphasizes battery energy storage systems as a strategic priority for its critical energy infrastructure."
This deployment builds on Tesla's prior projects in Japan, including a 6 MWh test and a 43 MWh system in Hokkaido, with a 548 MWh project in development. Japan's BESS market is projected to grow from $593 million in 2023 to $4.15 billion by 2030.
