Japan wants 10 GW of offshore wind running by 2030, building toward 30 to 45 GW by 2040. It had only 253.4 megawatts in the water at the end of 2024, which is why last year’s biggest industry setback still stings.
A Mitsubishi-led consortium walked away from 1.7 GW of projects it had already won, telling investors in August 2025 that the numbers no longer worked. The government has spent the months since rewriting its own auction rules and opening a much larger stretch of ocean to the floating turbines it’s counting on to close the gap.
How much offshore wind Japan has now
Japan’s offshore fleet is still mostly a short list of fixed-bottom wind farms bolted to the seabed near port cities. The newest and largest is Ishikari Bay New Port, which added 99.9 MW in January 2024. Before that came Akita Port’s 54.6 MW in January 2023 and Noshiro Port’s 84.0 MW in December 2022.
Picture your own town’s harbor with a turbine bolted into the seabed. That’s already true at Akita Port and Noshiro Port, both running commercial wind farms.
Two much smaller floating turbines have been running even longer, a 2 MW unit off Sakiyama since April 2016 and a 3 MW unit at Hibiki since May 2019, both demonstration projects instead of commercial wind farms. Add every fixed and floating site together and Japan had 253.4 MW running nationwide at the end of 2024.
Japan’s list of operating wind farms
| Wind farm | Type | Capacity | Operating since |
|---|---|---|---|
| Sakiyama | Floating | 2.0 MW | April 2016 |
| Choshi | Fixed | 2.4 MW | January 2019 |
| Hibiki | Floating | 3.0 MW | May 2019 |
| Noshiro Port | Fixed | 84.0 MW | December 2022 |
| Akita Port | Fixed | 54.6 MW | January 2023 |
| Nyuzen | Fixed | 7.5 MW | September 2023 |
| Ishikari Bay New Port | Fixed | 99.9 MW | January 2024 |
| Goto | Floating | 16.8 MW | January 2026 |
Source: Japan Wind Power Association, data through the end of 2024, plus offshoreWIND.biz on the Goto wind farm’s January 2026 start.
Why floating turbines matter here
A steel and concrete cylinder floats upright offshore Fukue Island, held in place by mooring lines instead of a foundation driven into the seabed. That’s Toda Corporation’s Goto wind farm, which reached commercial operation on January 5, 2026 with eight Hitachi turbines totaling 16.8 MW. The site sits in water 120 to 135 meters deep. It’s also 7 to 11 kilometers offshore, too deep and too far out for the fixed-bottom foundations used at Noshiro Port and Akita Port.
If deep water rules out a fixed foundation on your own project, this design is already running commercially at Goto.
The consortium calls its steel-topped, concrete-bottomed hull a hybrid spar and says it’s the first commercial use of the technology anywhere. Getting there took longer than planned. A defect found in the floating structure during construction pushed the start date back from January 2024 to January 2026, a change METI approved on September 22, 2023. The wind farm will sell power at 36 yen per kWh through December 2043.
How the government’s auctions work
Japan opened its coastal waters to wind developers when the Sea Area Utilization Act took effect in April 2019. As written, the law’s promotion zones covered only Japan’s territorial and inland waters. Regulators had already flagged four zones for fast-tracking by July 2019, the Akita and Chiba sites that later became Round 1, plus Goto in the south.
Under the feed-in tariff auction that followed, developers bid low prices to win a site, then get paid that fixed rate for years. In Japan’s first auction round, a Mitsubishi-led consortium won all three Akita and Chiba sites in December 2021, bidding 11.99 to 16.49 yen per kWh, well under the 29 yen ceiling the government had set. Those low bids left the projects almost no room to absorb what came next.
The mechanism behind Japan’s auctions works a lot like a fixed-rate deal on your own utility bill, a price locked in for years no matter what fuel costs or the yen does later.
What went wrong for Mitsubishi
Mitsubishi Corporation said in its August 27, 2025 announcement that it would not proceed with any of the three sites, citing tight supply chains, inflation, exchange rates and rising interest rates since its 2021 win. By the time the company pulled out, costs had more than doubled and total investment passed 1 trillion yen. If you own Mitsubishi Corporation shares, that reversal already hit the numbers you’d see in its filings, a 52.2 billion yen impairment, on top of as much as 20 billion yen in penalty payments for abandoning sites it had already secured.
The inflation behind that reversal shows up across Japan’s construction sector. Average offshore wind construction costs there rose 20% between fiscal 2020 and fiscal 2024, compared with an 8.5% rise in consumer prices over the same years. The yen has made imported equipment costlier too, falling 109.78 in 2021 to 151.50 in 2024 per dollar, a 38% drop. On top of that, Japan has no domestic manufacturer of large offshore wind turbines, so every project leans on imports exposed to that weaker yen.
Permitting adds years developers in other markets don’t lose. A fixed-bottom project in Japan can take 6 to 8 years to build, versus 2 in the EU, which caps its own permitting timeline. If you’re financing the project, you feel that gap directly, years of carrying costs before a single turbine turns.
The rule changes underway
Auction rules changed too. Starting with Round 4, new rules from January 2025 let developers pass up to 40% of cost inflation through to the electricity price between winning a site and starting construction. The same reform doubled the bid bond, from 13,000 to 24,000 yen per kilowatt, meant to discourage the kind of aggressive bidding that sank Mitsubishi’s sites.
A second round of measures in November 2025 added 20 years of guaranteed capacity revenue for zero-premium projects from Rounds 2 and 3, through a separate power auction, on top of allowing developers to swap in a new turbine supplier if theirs backs out.
Turbine makers outside Japan are the ones who gain from that swap-in rule. If a developer’s original supplier drops out mid-project, this is the rule that lets your factory step in instead.
Regulators also went after the map itself. On March 7, 2025, the Cabinet approved a bill letting developers build in Japan’s exclusive economic zone as well as its territorial waters, and parliament passed it in June 2025. That water tends to run deeper, which is exactly the depth floating designs like Goto’s are built for.
Whether Round 4 avoids Round 1’s mistake
The government postponed Round 4, originally planned for October 14, 2025, to work out why the Round 1 developer walked away before opening a new round to the same risks. Officials are also weighing whether to reauction Mitsubishi’s three abandoned sites under the new rules. If that’s your market, that reauction decision is the one to plan around.
Floating wind’s record in Japan includes NEDO’s 7 MW demonstration turbine off Fukushima, which went up in July 2015 and was towed away for dismantling in May 2020 instead of joining the operating fleet.
Not every project is waiting on that outcome. The Round 3 winners off Aomori and Yamagata are both targeting commercial operation in June 2030 using Siemens turbines, and Tohoku Electric’s Aomori site is moving ahead too. Whether Japan reaches its 10 GW target for 2030 depends on whether the rewritten auctions produce bids that survive construction, unlike the ones Round 1 cleared only on paper.
For more on the technology behind these projects, see how offshore wind power works generally, and how wind power growth compares across countries.
