Return to Fukushima: the floating wind pilot that could re-energise Japan's offshore voyage

A decade after the island nation's pioneering demo project off stricken nuclear plant reached first power, Tokyo Gas believes new 30MW array could be a 'small project with big value' as country's government plans gigascale arrays, writes Darius Snieckus

A Principle Power WindFloat topped with Vestas turbine heading for the WFA project off Portugal in 2019
A Principle Power WindFloat topped with Vestas turbine heading for the WFA project off Portugal in 2019Foto: Principle Power
Twenty-five kilometres out to sea from the site of Japan’s 2011 Fukishima-Daiichi nuclear disaster, plans are gathering pace to build a two-unit floating wind power project. Though at 30MW small in size at a time when international energy developers are gearing up to build gigawatt-scale arrays in the world’s major maritime provinces, the pilot could be disproportionately influential to both the emerging sector as well as Japan’s wider industrial future.
The project, being built by utility Tokyo Gas, is a return to deep water wind for the Asian island nation, an early adopter of floating technology that within three years of the melt-down in Fukushima had switched-on the world’s first multi-unit array – the eponymous Fukushima Forward demonstratorbut has since has made little progress in the field beyond an 16MW array off the Goto Islands.

Proving floating wind’s commercial viability using today’s ultra-large turbines models and next-generation platforms is the central rationale of the project, to constructed in 100-200 metres of water using 15MW machines and Principle Power hulls. Yet for the utility and the country, the pilot carries a much larger resonance too.

Japan is home to a power-hungry population of 125 million increasingly calling for a renewables-led energy transition away from fossils and nuclear. But the island has limited acreage on land for solar and only the narrowest of continental shelves to accommodate bottom-fixed offshore wind projects, making floating key to the government’s goal to have 45GW of plant turning at sea by 2045where it currently has only 140MW operatingas part of a national net-zero energy mix.

“Knowing the geographic conditions of Japan there will be massive potential for floating wind and we want to be the front-runner here in this industry. Deploying floating wind technology into Japanese waters is our main focus,” says Michiko Hirose, the head of the offshore wind business at Tokyo Gas, which made a ¥2bn ($15.6m) investment in Principle Power in 2020.

“We are starting with a small-scale, pre-commercial project that we need to launch to go through the Japanese process, including the certification bodies and so on. Our aim is to take floating wind quickly into industrial-scale. Getting costs down means scaling up.”

“I am often asked why we do not start with a large-scale floating wind project, given precommercial-scale projects already been deployed in Europe,” she adds. “But we believe it is essential, especially in Japan and in metocean conditions that are very unique, because we need to speed up progress in this sector, from certification on, if we are to achieve the national goals set.”

Tokyo Gas’ lofty ambitions for this new Fukushima flagship are anchored in an informed conservatism around the technologies involved. The Fukushima Forward demonstrator offered many hard lessons to the Japanese industrial consortium that devised it – as it did the wider offshore wind sector – but the biggest take-home was ‘floating wind is high-tech and high-cost’.
The desire to “rule out risk with mature technology” led Tokyo Gas to choose Principle Power’s steel semisubmersible WindFloat platform, first prototyped off Europe in 2011 before going on to be used on two of the largest floating wind arrays operating, the 25MW WindFloat Atlantic off Portugal and the 50MW Kincardine in the North Sea off Scotland.
Our aim is to take floating wind quickly into industrial-scale. Getting costs down means scaling up

Tokyo Gas' Michoke Hirose

Principle Power’s chief commercial officer Aaron Smith says: “Taking a technology that you know works and deploying it here [off Japan] should be a guaranteed success and this is a prerequisite for people [in government and industry] to become comfortable with the prospect of gigawatt-scale, over-the-horizon type projects.

“In all the markets we are in, we see having steel in the water is a complete gamechanger. It gives countries confidence to move. So, this small project off Fukushima [because it is managed by a prefectural regime rather than national auction system] is going to be a way to get steel quickly into the water.”

Though Japan has world-leading maritime and shipping industries and highly developed coastal infrastructure, to meet the demands of a fast-growing floating wind market the country’s network of ports and harbours will need to be the “first area focused on”, said Smith, as these facilities will underpin a virtuous circle of development of the local supply chain and accompanying job creation as deployment gains momentum.

“We think that Japan has a huge opportunity and it is about how you unlock the move to scale,” he said. “If you have ports that are ready on time [ to support lead-off industrial scale projects] then you build the supply chain behind them. You can make sure there is a place to build and install turbines locally and that is really important when it comes to deciding where to put new factories or facilities.”

Hirose adds: “Getting to gigawatt-scale we will need a strong supply chain in Japan. We knew Principle Power’s platform technology was the right one for Japan’s geographic conditions, so, with their collaboration, we are launching a programme that looks into developing the supply chain for mass production [of the WindFloat] using a modularised design.”

Japanese reconnaissance mission

Tokyo Gas’ Fukushima pilot will be a reconnaissance mission for the industrial development needed if floating wind is going to take up the place foreseen for it by the Japanese government off its shores – and as urged on by the Japanese Wind Power Association in its lobbying to open vast areas beyond its territorial waters in the so-called Exclusive Economic Zone (EEZ) as part of a package of “urgent measures” to spur on progress in the sector.

The first phase of Tokyo Gas’ Fukushima pilot will focus not just on the manufacture – “How to build it and also where to build it,” says Hirose – but also the installation process for the single units and how it can we extrapolated for future gigascale projects. “We are looking for the right pots and shipyards for the pilot while thinking about the future too,” she says.

“Our government is looking into reforms to offshore wind policy and may launch the next phase of its [Green Innovation Programme] this year that has taken expressions of interest from potential governmental authorities where potential ports are located, after which ports to receive support will be selected.”

A follow-on phase of the Tokyo Gas project would be timed with the next Japanese offshore wind auction, to bring in a developer to partner on expanding out the project from pilot to industrial-scale, potentially as large as 1GW, in the process helping “push this supply chain creation to a much higher level”.

Smith adds: “One of the challenges of these smaller projects is that you have to make do with what [coastal industrial infrastructure is] available to start with because you simply cannot afford to cover huge capex [capital expenditure] outlays for this sort of thing.

“What we are trying to do is to leverage the lessons from [building the WFA and Kincardine projects in] Europe against the engineering work we are doing in Japan and the base ports concept from MLTI [Japan’s ministry of land, industry and transport] to make sure these [industrial hubs] can built in the right locations and with the right features that are future-proofed for the industrial scale-up ahead.”

While the new Fukushima pilot has its share of obstacles to surmount, it has at least one ace in the hole: a digital vault of sea and wind data collected over a decade at the site, via sensors on the original demonstrator’s substation platform.

“This is a real opportunity to have when designing the WindFloat units for our project and by utilising the know-how obtained through the floating demonstration project off the coast of Fukushima, we expect to trim a few years off the timeline,” says Hirose.

WindFloat’s generation game

The WindFloat platform started as an import from the offshore oil & gas industry, a scaled-down steel semisubmersible engineered around a three-column ballasting system that has evolved over the last decade through three design generations. The triangular hulls have been fitted with turbines from 2MW up to 10MW models, but for the Fukushima pilot will be mated with giant 15MW machines for the first time.

Submission of the project’s environmental impact assessment – a key milestone in the project timeline – now done, Tokyo Gas foresees construction starting in 2026 and rotors turning the following year.

“The industry has had experience with many sizes of turbine but I do think 15MW turbines present challenges though it will be achievable, working with Principle Power,” says Ryo Isawa, who is heading up Tokyo Gas’ floating wind department.

“We believe using WindFloats will be a big advantage here not just only for this pilot but also for future commercial-scale projects because of the track-record off Europe of bankable projects and the maturity of this technology.

“This knowledge is very important as we attempt to take floating wind to the next level in Japan, that is industrial-scale [and] long-term operation.”

Constructing the new Fukushima floating wind pilot goes far beyond industrial considerations, with stakeholder management, marine spatial planning and ocean co-habitation all pressing matters for Tokyo Gas and other developers. While there remain “sensitivities” in dealing with the Japanese fisheries, the general public’s view of offshore wind is almost uniformly in favour of the industry and its more rapid development in the country, says Hirose.

“We [Tokyo Gas and Shinobuyama Fukushima Electric Power] have recently announced a plan to proceed with the environmental impact assessment. Through this process, we will endeavour to continuously discuss and try gaining the understanding of the local fisheries, residents, and relevant governments.

“More generally we are encouraged to receive positive comments from our stakeholder meetings where offshore wind, especially floating is seen in a very positive light. I hear many aspirations and hope for this new industry and its future,” says Hirose.

The government’s reportedly imminent plans to throw open the EEZ to wind plant development under the aegis of a five-year plan to reform Japan’s maritime policies between 2023-2027, has the potential to transform the pace of development of its slow-burning sector, which has a 60GW pipeline of offshore projects ready to be uncorked.

“The EEZ is necessary for our industry to scale up to gigawatt scale. It is good news that this now happening,” says Hirose, noting that the pilot project is “very close” to the EEZ and could be expanded “if the conditions were right”.

“This small pilot has big value,” says Smith. “We are going to be extracting lessons all the way through. It’s not a case of having to wait until the project is completed before you can see the wider value, from development of the supply chain through to expanding the ambition to building floating wind at true commercial scale off Japan.”

(Copyright)
Published 3 April 2023, 22:05Updated 14 October 2023, 13:14
Tokyo GasPrinciple PowerJapanAsia-PacificOffshore wind