Check out the giant ship critical to building the world’s biggest offshore wind farm

A project to build a facility described as “the world’s largest offshore wind farm” took a big step forward this month by producing its first power.

Located in the North Sea, over 130 kilometers off England’s northeast coast, the Dogger Bank Wind Farm still has some way to go before it’s fully operational, but the installation and powering up of its first turbine is a major feat in itself.

That’s because GE Vernova’s Haliade-X turbines stand 260 meters tall — that’s higher than San Francisco’s Golden Gate Bridge — and have blades measuring 107 meters.

Turbine installation at Dogger Bank has required a huge amount of planning and preparation, with the Voltaire — a specialist vessel designed and built by the family-owned Jan De Nul Group — playing a key role.

With a lifting capacity of 3,200 metric tons, the Voltaire — named after the 18^th-century French philosopher — will have installed a total of 277 Haliade-X turbines when its work is complete.

Described by Dogger Bank as the “largest offshore jack-up installation vessel ever built,” in many ways, it’s the pinnacle of an extensive supply chain involving numerous businesses and stakeholders.

The logistics are complex and multi-layered, with water depth a particular issue.

The sea in the Dogger Bank Offshore Development Zone is up to 63 meters deep, meaning the Voltaire’s ability to work in deeper waters is crucial. 

This is where its four legs come into play.

According to Jan De Nul, the legs of the Voltaire — which was built at the COSCO Shipping Shipyard in China — enable it to lift itself above the water’s surface.

With each leg measuring roughly 130 meters in length, they highlight the scale of equipment required to install huge offshore wind turbines like GE’s Haliade-X.

In an online Q&A before installations at Dogger Bank began, Jan De Nul’s Rutger Standaert spoke of their importance. “Thanks to those legs, the Voltaire can effectively operate at a water depth of 80 meters,” Standaert, who is manager of vessel construction at the business, said.

He noted that the Voltaire’s capabilities would enable installations further out to sea, allowing it to play a key role in the emerging floating offshore wind sector.

“Off the Scottish coast, for example, expensive floating windfarms are often the only way to tap into offshore wind,” he said. “The water is too deep for fixed windfarms, but the Voltaire can offer new opportunities.”

Thinking big

Once completed, the Dogger Bank Wind Farm will have a total capacity of 3.6 gigawatts (GW) and be able to power as many as six million homes per year, according to its developers.

Work on the project is taking place over three phases: Dogger Bank A, B, and C. A fourth phase of the wind farm known as Dogger Bank D has also been proposed, and would increase its capacity even further.

Søren Lassen is head of offshore wind research at Wood Mackenzie, a research and consultancy group. He described Dogger Bank as “a huge project, especially if you combine the three phases.”

“It is a project that requires a lot of preparation,” he told CNBC. “There’s the logistics in terms of having the vessels to do the installation … and then of course, you also have the logistics in terms of getting the components to the marshaling port.”

Both of these aspects were being made “a lot more complicated” by the use of next-generation turbines and a next-generation installation vessel, Lassen said.

“You have … a lot of innovation that goes into this. And not only do you need a new vessel or new components, you also need new factories to build those components.”

As such, a slew of upgrades and adjustments were needed to “reverberate throughout the entire value chain” for operations to run smoothly, he added.

Bigger turbines, bigger challenges?

Thanks to their sheer size, larger turbine designs have created a specific set of needs for the offshore wind sector and sites like the Dogger Bank Wind Farm.

“From cranes to vessels, we use a number of specially designed pieces of equipment to transport the Haliade-X turbines that will be used in this project,” a spokesperson for GE Offshore Wind said in a statement sent to CNBC.

Wood Mackenzie’s Lassen stressed the importance of having dedicated transportation vessels, noting that the towers of turbines need to be broken into three or four sections in order to fit on board.  

Massive blades represent the biggest challenge, he said, as they have to be laid flat. “And that just means that you need a very, very long transportation vessel, [and] that you need to stack them up accordingly.”

Meanwhile, delays or bottlenecks can have far-reaching — and expensive — consequences.

Lassen cited the example of blades not being delivered on time, which leads to vessels having to “go away and then come back half a year later to do the installation. This is very costly, of course.”

And delays also lead to lost revenue.

“These projects are going out [and] generating a lot of power from the day that they’re being installed, pretty much,” Lassen added.

“So any delays [and] you’re also losing a lot of revenue, especially right now when the power prices are really, really high.”

The bigger picture

Offshore wind farms are set to play a significant role in reducing emissions and hitting net zero goals in the years ahead — but a supply chain that’s well-run and reliable will be key to the industry’s success.

This is set to cost serious money. According to Wood Mackenzie, a base case of 30 GW of installations per year by 2030 — excluding China — will require investment of around $27 billion by 2026 to build out supply chains.

“The supply chain needs to invest,” Lassen said, adding that it also needed capital, certainty and concrete, firm orders. However, cost pressures mean there is currently uncertainty over projects planned for 2025, 2026 and 2027.

“Any delays to these projects takes away volume from the supply chain, and the supply chain needs that volume to convert it into revenue to build new factories,” Lassen explained.

It is crucial that projects planned for the next few years go ahead, he added. “That helps the underlying supply chain ramp up so they can build the capacity [for] ’27, ’28, ’29 and well into the 2030s as well.”