Aegir DEEP DIVE | ‘Not a PowerPoint technology’

Aegir DEEP DIVE | ‘Not a PowerPoint technology’

"Radical new floating wind design readies to brave the waves." begins an in-depth article in Beaufort, (December 1, 2023) Aegir Insights’ weekly market intelligence read for commentary, analysis, and in-depth journalism on the global offshore energy transition, highlighting World Wide Wind's novel approach to floating off-shore wind.

You can read the full article here.

With new CEO Bjørn Simonsen at the helm, Norway's World Wide Wind is on track to have a part-scale prototype of its innovative deepwater turbine moored in the North Sea by year-end – and a giant 24MW model in the water by 2030, writes Darius Snieckus

The computer-generated images of long-horned white towers tilting among the whitecaps of wild northern seas that were released with the launch of World Wide Wind’s new-look floating wind concept last year divided industry opinion. Many saw the so-called contra-rotating vertical turbine (CRVT) as a paragon of the disruptive technologies needed to speed the fledgling sector into the industrial mainstream, others one more futurist’s fantasy that would soon sink out of sight.

But the Norwegian start-up, now being led by recently appointed CEO Bjørn Simonsen, is already well on its way to proving the skeptics wrong, with a part-scale prototype of the eye-catching design, which features two omnidirectional rotors on a mammoth tower-spar structure anchored to the seafloor with a novel mooring system, on track to be in the water by year-end.

All going to plan, the pilot off Vats in the south-west of the Nordic nation, will accelerate scale-up of the concept to a 1MW flagship by 2025 – and then before the decade is out to a gargantuan 24MW model that could be flowing power the grid at a price potentially 75% lower than the conventional three-bladed floating units now operating off Europe.

“For the world to reach net-zero, the relevance of offshore wind and certainly floating wind has just grown,” says Simonsen, who came to the top job at WWW following 15 years in the hydrogen technology space. “And as we all know, the industry is struggling. It is costly to move a technology [the wind turbine] that's been optimized for operating on land, out in a liquid environment, and the costs are increasing with the complexity, as are the doubts around the size of these latest [12MW-plus] turbines. How big can you go – or should you go? “We can always push the boundaries in scaling up, but it appears we're reaching a plateau with horizontal axis turbines.”

WWW aims to take vertical axis wind turbines (VAWTs) – which have blades set at angles to the tower rather than upright as on the vast majority of industrial model turning today – past the impasse which has until now derailed a technology long-heralded as key to harnessing the vast, high-velocity wind resource streamline over the world’s deep waters: torque.

LEANING IN: World Wide Wind's deepwater contra-rotating vertical turbines are designed to 'work with' the wind (IMAGE: WWW)

As with many other VAWT designs, the CRVT has its generator fitted into the base of the tower – meaning it does not need to be engineered to be light and compact like those built-in to conventional turbine nacelles where mass equals added cost – and can use inexpensive ferrite magnets rather than those using rare earth material-base ones.

Contra-rotating rotors deflect away the “destructive levels of torque and vibration” that over the past decade have put paid to other VAWTs, including oil & gas contractor Technip’s VertiWind, UK outfit WPL’s Aerogenerator, and a design advanced by France’s EDF and Nenuphar, and, by WWW’s calculations could produce power at a levelized cost of energy (LCOE) below €50/MWh in the process, competitive with bottom-fixed offshore wind.

“Our design does not stand upright and ‘against’ the wind, it leans just like a sailboat or a tree. And because as it leans the swept area is smaller [than supersize carbon-and-fiberglass-bladed rotors] which don’t, the CRVT works ‘with’ the wind and does not have to shut down in very high winds because it has more inherent stability built into it,” says Simonsen.

The CRVT promises other advantages over its floating wind brethren. The spar foundation is concrete, cheaper and more sustainable than steel, in WWW’s view, while the tower, not needing to support a heavyweight nacelle, is made of low-cost recycled aluminium and glulam – wood laminations bonded with moisture-resistant, high durability adhesives.

‘Optimal’ use of sea space

But most of all, says Simonsen, the new-look design will make “optimal” use of space at sea, with twice as many 24MW WWW turbines fitting into a square kilometer offshore than three-blade floating units, which have rotor diameters of well over 200-metres.

“LCoE ultimately all depends on what time frame you have and what assumptions goes into your calculations So we think we can get to an LCoE sufficiently below that of the biggest horizontal axis [turbine designs],” he says. “However, we think what is going to make our technology very attractive is its ability to produce more power from the same area at sea, around twice as much per square kilometer. And that will likely be what will get the big developers to say: ‘Let’s go for [the CRVT]’.

WWW is not alone in this view. Norwegian aluminium giant Hydro early this year signed up to supply the metal alloy sheets to be used for CRVT – expected to be as much as 50% lighter than steel semisubmersible floating wind platforms supporting a comparative-sized turbine – and compatriot industrial group AF Gruppen last month agreed to host the prototype tests at a site at its environmental base in Vats, near Haugesund.

“We've got collaborations with the key suppliers that we will need to succeed with our turbine. And because we are building the spar in concrete, the mast in glulam and the blades in glulam and recycled aluminium, we are taking known materials that have been proven in the marine environment [and using them] for this a new application – floating wind – which is where we are innovating,” says Simonsen. “Working closely with those suppliers, having a dialogue from earliest stages, is extremely important to ensure that they can help us figure out what are the best solutions for our design.” 

The 19-meter-long 30kW prototype is on track to be installed “by end of the year or early next”, he adds, launching a follow-on “Mark 2” 30kW prototype shortly thereafter, that “implements some early learnings to help [WWW] fast-track” construction of the near-100-meter-tall 1.2MW pilot unit that it plans to have in the water by late-2025. By 2030, WWW expects to have the 24MW model, which will be nearly 400 meters from tip-to-base-of-spar, ready for first projects.

“This is not just a PowerPoint technology. We are building [the first two units] now and very soon we'll have them in the water,” says Simonsen. “We are very aware that especially with a technology like ours – which of course doesn't look at all like a conventional wind turbine – seeing is believing: how it contra-rotates, the tilt, how it behaves in a real offshore environment. Seeing that the design works with nature not against it.”

Should the WWW vision for floating wind become full-scale reality, it is hard to overstate the likely impact. In its home play, where the government is laboring to launch lead-off auctions, the 1.5GW Sørlige Nordsjø 2 in the southern North Sea, and the 1.5GW Utsira Nord in the deeps off the west coast, the CRVT could create a sea-change in thinking for a country still trying to join-up a target of having 30GW of offshore wind in development by 2040 with an industrial transformation for its oil & gas supply chain.

“Seen from a Norwegian perspective, to lead the way in this field [of floating wind], the money the government spends should trigger new industrial development nationally,” says Simonsen, agreeing progress has been slow-rolling for the sector, which has only two floating wind prototypes turning until the 95MW Hywind Tampen project was brought online this year.

Floating wind’s ‘future demand’

“[As a country] we don't need this power source now or in the near-term, but we will need more clean electricity going forward. And floating wind is where all the new innovation is going to happen [to meet this future demand]. That's where we can really make a difference from what we're doing in Norway. “Utsira Nord – and the [accompanying] Norwegian floating wind efforts – is extremely important for our industry’s international competitiveness, to push boundaries, and to help foster new concepts like ours. And also to support the supply chain and infrastructure development that is needed too.”

DEEP THINKING: World Wide Wind's contra-rotating floating wind turbine is a departure from conventional engineering for deepwater designs (IMAGE: World Wide Wind)

Simonsen underlines that though the “original” floating wind ‘roadmap’ toward 14-16GW by 2030 “might not be reached on schedule”, the sector’s step-wise scale-up “is happening”.

“With [the 95MW Hywind Tampen] we now have more-or-less 100MW scale and we are heading for 500MW [at Utsira Nord]. And, looking beyond that, with the areas that have been marked out by [the Norwegian government] off our coasts, those alone can cater for 250-500GW of floating wind – so then we're talking truly a scale which will enable Norway to maintain the power position on energy and supply the world with energy indefinitely,” he says. “So, I'm optimistic. Having [a technology such as the CRVT] that can be realized will help not only the energy industry going forward but – assuming we succeed – then the world’s need for huge [volumes] of clean electricity as the energy transition accelerates.

The “macro” in floating wind like all emerging sectors “works against new innovative solutions”, he admits. “Governments are hunkering down and becoming very myopic in terms of national needs and energy security and safe havens become more and more important, both for investors and for politicians etc.

“Things are moving forward though,” he says. “[Milestone] projects are getting into the water and starting to produce power and that's a tremendous step forward for the industry. And at the same time, it is also revealing that floating wind is still costly – and that's why you have the negativity from some out there.

“But this, [in turn,] should also raise awareness around solutions like the one we are developing and that can unlock a new cost [paradigm] for the international energy industry. “Radical technology shifts in any sector aren't for all investors either,” Simonsen agrees. “You have to want to be part of a journey where the risks are higher, but the rewards are a lot higher also. What convinced me [to move from hydrogen technology investment] is I realized that [the CRVT] is how all wind turbines will one day look out in the deep waters. It makes so much more sense.”

FINDING NEW PURPOSE: AF Gruppen's Vats base in south-west Norway, long used for decommissioning offshore oil vessels, will be the installation site for World Wide Wind's part-scale floating wind prototype (FOTO: AF Gruppen)

This article was first published in Aegir Insights' intelligence newsletter, Beaufort.

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