Japan’s Ministry of Economy, Trade and Industry and Ministry of Land, Infrastructure, Transport and Tourism on July 14 set out a more selective approach to offshore wind development, proposing that future project formation should initially focus on sea areas capable of delivering electricity at roughly ¥30 per kilowatt-hour or less.
The benchmark was presented at a joint meeting of the 44th Offshore Wind Promotion Working Group and the 49th Offshore Wind Promotion Subcommittee. It is not a bid-price ceiling, strike price or retail tariff. Rather, it is an early-stage screening metric intended to help the government decide which prospective zones merit priority development as the sector grapples with higher equipment costs, a weaker yen and rising financing rates.
Source: Material 1, “The operating environment for offshore wind and the near-term approach to project formation”, p.6.
A screening threshold, not an auction cap
The government material estimates the levelised cost of newly commissioned offshore wind in 2023 at ¥30.9/kWh. A separate Japan Wind Power Association assessment, based on five fixed-bottom monopile projects, also placed costs in the mid-¥30s. That estimate assumes a 3 per cent discount rate and a 6 per cent project internal rate of return, and includes onshore transmission and grid-connection expenditure.
Project economics will nonetheless vary sharply with wind resource, water depth, distance from shore, port access, construction complexity and the scale of required network reinforcement. The ¥30 figure should therefore be understood as a portfolio-screening benchmark rather than a uniform price applicable to every development zone.
The policy logic is straightforward. LNG-fired generation, nuclear power, utility-scale solar and Japan Electric Power Exchange spot prices were shown broadly in the ¥10/kWh range. Prioritising offshore sites with stronger cost fundamentals is intended to limit the risk that accelerated deployment translates into excessive consumer or taxpayer burdens.
Capital-cost pressures have intensified
The ministry’s data show an offshore wind capital-cost index rising 19 per cent between January 2024 and March 2026. Over a similar period, the yen weakened by 9 per cent against the dollar and 16 per cent against the euro, while the yield on 20-year Japanese government bonds increased by 150 per cent. Construction costs rose 9 per cent and transmission-cable prices surged 67 per cent.
Source: the same government material, p.3.
These movements are particularly damaging for a capital-intensive industry. Turbines account for an estimated 55 per cent of project capex and construction work another 32 per cent, followed by foundations at 6 per cent and array and export cables at 5 per cent. Imported turbines and cables expose Japanese projects to both global supply-chain inflation and currency risk, while higher interest rates lift the cost of long-dated project finance.
Site selection and industrial policy are becoming inseparable
The emerging approach would rank prospective zones using not only wind conditions but also water depth, proximity to ports, installation difficulty and grid-connection requirements. The challenge is that cost estimates made before formal designation remain uncertain. Commodity prices, exchange rates, interest rates and supply-chain capacity can all change materially before financial close.
Japan must also balance near-term affordability against its industrial-policy objectives. The public-private target is to raise domestic procurement to 65 per cent by 2040. The meeting material cited Vestas’ plans for nacelle assembly by 2029 and the prospect of fuller manufacturing by 2039. Yet local factories need a credible, sustained order pipeline. Excessive project rationing could weaken scale economies and deter inward investment; moving too quickly could lock consumers into structurally expensive projects.
Floating wind must cross the gap from demonstration to bankability
Floating offshore wind remains strategically important because much of Japan’s coastline reaches deep water close to shore. The draft roadmap envisages technology demonstrations between 2027 and 2032 under deep-water and severe metocean conditions, supplemented by experience from overseas projects.
Source: the same government material, p.15.
The government is also considering an intermediate commercial-scale demonstration of roughly 300MW. Such a project could bridge the gap between component-level trials and utility-scale deployment, producing the operational and cost data needed for bankable projects, standardised engineering and a domestic supply chain.
What the ¥30 benchmark means for investors
Public discussion has produced sharply different readings of the benchmark. Some regard ¥30/kWh as too expensive relative to competing generation sources; others argue that it is already demanding under current equipment and financing conditions. It has also occasionally been confused with the ceiling used in Japan’s long-term decarbonised power auction. The two mechanisms serve different purposes.
The offshore wind benchmark guides the administrative sequencing of project formation. It does not directly determine the price at which a project will win an auction. The next question is how the government will compare site-specific costs and allocate expenditure for grid reinforcement, port upgrades and fisheries co-ordination.
Japan’s offshore wind strategy will ultimately be judged on whether it can reconcile four objectives that do not always pull in the same direction: cost discipline, energy security, local consent and the creation of a competitive domestic industry.