Battery Energy Storage Investment in Japan: Opportunities and Legal Considerations for Foreign Investors

Japan’s battery energy storage system, or BESS, market is becoming a more concrete investment sector. The opportunity is driven by Japan’s renewable energy targets, the need for grid flexibility, and the development of electricity market mechanisms that may support BESS revenues.

Under the 7th Strategic Energy Plan approved by the Cabinet in February 2025, renewable energy is expected to account for approximately 40% to 50% of Japan’s power generation in FY2040, compared with 22.9% in FY2023. The same policy framework assumes that electricity demand will increase due to digital transformation, green transformation, data centres, semiconductor plants and other growth industries. This creates a practical challenge: Japan needs more decarbonized electricity, but it also needs resources that can balance variable renewable output and support stable supply.

BESS is one of the main solutions. A grid-scale battery can charge when electricity is abundant or prices are low, and discharge when demand is high or supply is tight. It can also provide fast-response balancing capacity and improve the value of renewable energy projects by reducing curtailment exposure and shifting supply to more valuable periods.

Why Japan is attracting foreign investors

Japan’s BESS market remains less mature than storage markets in jurisdictions such as Australia, the United Kingdom, parts of Europe and the United States. This creates opportunities for foreign investors with experience in project development, battery operation, trading, optimization and infrastructure finance.

Recent market activity indicates that foreign capital is already moving into Japanese storage projects. Investors are looking at Japan because deployment has been slower than in certain overseas markets, while policy support, electricity market reform and grid needs are making the sector more investable.

For foreign investors, the opportunity may take several forms, including acquisition of development-stage projects, joint ventures with Japanese developers, investment in a storage platform, project financing, or development through a Japanese project company.

Revenue model: not one income source

A Japanese BESS project is often assessed as a revenue-stacking project. Unlike a renewable energy project supported mainly by a fixed tariff or premium, a standalone grid-scale battery may seek to combine several revenue sources. This gives the project more commercial flexibility, but also makes due diligence on market access, technical eligibility and operating arrangements more important.

Wholesale electricity trading may form part of the revenue model. The Japan Electric Power Exchange operates a day-ahead spot market and an intraday market. A battery can charge during lower-price periods and discharge when prices are higher, with the economics depending on market spreads, trading arrangements, operating costs, imbalance exposure and battery performance over time.

BESS may also be used for electricity balancing and capacity-related mechanisms. Batteries can respond quickly to supply-demand fluctuations, which makes them relevant to grid flexibility. Participation in electricity balancing and capacity-related mechanisms depends on the applicable market rules, product category, response time, duration, metering, registration and operational arrangements. Where an aggregator or trading operator is involved, the contract should clearly address dispatch rights, revenue sharing, performance obligations, imbalance costs and operational liability.

The Long-Term Decarbonized Capacity Auction is particularly relevant for grid-connected storage batteries. For qualifying projects, this may provide a more stable revenue component, although the auction rules, eligibility requirements, delivery obligations, penalties and interaction with other revenues should be reviewed carefully.

BESS may also be combined with renewable energy projects, including projects under the Feed-in Premium, or FIP, regime. The Strategic Energy Plan refers to supply shifting using storage batteries as an example of action encouraged under the FIP system. In this structure, storage may help shift renewable electricity to periods with higher market value and reduce curtailment exposure. The legal structure should be confirmed, including whether the battery forms part of the generation project, is held as a separately owned asset, or is operated through a third-party service arrangement.

Each revenue source should be reviewed separately and in the context of the overall project structure. Legal due diligence should confirm market or auction eligibility, required registrations, metering arrangements, dispatch rights, revenue entitlement, performance obligations, imbalance costs and liability for non-compliance. Changes in market rules, auction requirements, grid restrictions or battery performance may affect both project returns and contractual risk.

Key legal and commercial issues

BESS projects are infrastructure projects, not simple equipment purchases. Legal due diligence should cover land, grid access, electricity regulation, construction, safety, market participation, contracts and corporate structuring.

Grid connection is often the most important value driver. Investors should verify the connection application status, available capacity, reinforcement costs, expected timeline, curtailment risk, operational restrictions and the terms of any interconnection arrangements.

Land rights also require detailed review. Investors should confirm ownership or lease rights, access roads, easements, zoning, neighbouring land use, security interests and restrictions under land-use regulations or local ordinances. Depending on the site, issues may arise under agricultural land rules, forest land rules, city planning regulations or disaster prevention requirements.

Permitting and safety should be assessed early. Depending on the project scale, battery specifications and local rules, consultation or procedures with local governments, fire authorities or other authorities may be required. Fire prevention, emergency access, monitoring, ventilation, incident response and decommissioning should be considered at the design and contract stage.

Project contracts should be reviewed as an integrated package. Battery supply, EPC, O&M, land lease, grid-related, optimization and financing documents should clearly allocate delay, degradation, availability, warranty, safety, insurance, termination and replacement risks.

Foreign investors should also assess Foreign Exchange and Foreign Trade Act requirements at an early stage. In energy-related sectors, prior notification is often the key issue, particularly where the investment involves acquiring shares or voting rights in a Japanese company, appointing directors, or otherwise obtaining influence over management. Any required filing should be built into the transaction timetable, as clearance may be a condition to closing.

Common investment structures

Foreign investors typically enter the Japanese BESS market through greenfield development, acquisition of a development-stage project, a joint venture with a Japanese partner, or investment in a project platform. Where the investment is structured as passive or fund-style participation, a GK-TK arrangement may also be considered, subject to tax, regulatory, governance and financing analysis.

Greenfield development may offer greater upside, but involves development risk from site selection through grid connection, permitting, construction and operation. Acquisition of a development-stage project may be more efficient where land or grid milestones have already been achieved, but the purchase price should be linked to verified progress. Joint ventures can be effective where a Japanese partner contributes land sourcing, grid experience, local authority relationships or a project pipeline. Platform investment may offer scale, but requires both corporate due diligence and project-by-project review.

Our support

Together with LPA Law Office, we assist foreign investors throughout the full lifecycle of BESS investment in Japan, including market-entry structuring, Japanese entity formation, FEFTA analysis, legal due diligence, land and regulatory review, transaction documentation, project contract review, permit support and post-closing compliance.

Our support covers the review and preparation of letters of intent, share purchase agreements, shareholders’ agreements, joint venture agreements, development agreements, EPC contracts, battery supply agreements, O&M agreements, optimization agreements, lease agreements and related project documents.