‘Desperate developers’ need wooden wind turbine blades, says start-up CEO

Making wind turbine blades from wood is cheaper and solves many of the “headaches” that come with conventional methods and materials, says the CEO of a start-up behind the idea, who also claims some developers are “desperate” to get their hands on them.

It all began with a “silly chat,” said Tom Siekmann, on the origins of Voodin Blade Technology, the wooden wind turbine blade company of which he is CEO.

That chat took place in 2019 between a wind energy developer and a blade engineer, who Siekmann said had a “shadow following him” throughout his career that he was working in a sustainable industry but “not really making the most of sustainability”.

Sustainability in the wind sector is a growing concern as the energy transition matures and the first generation of turbines approach their end of life.

University of Cambridge researchers have estimated that by 2050 there will be 43 million tonnes of blade waste globally. Voodin puts the figure at 50 million tonnes – around the same weight as the Great Wall of China.

Back in 2019, the blade engineer, who Siekmann said wants to remain anonymous for now as he remains involved in other projects, at first “jokingly” raised the prospect of making blades out of wood – harking back to old Dutch windmills.

The engineer investigated further and found that laminated veneer lumber (LVL), a material made up of thin wooden layers sealed together with adhesives, has a similar stiffness-to-weight ratio as the glass fibres typically used in turbine blades.

“So then the joking stopped.”

The engineer and a few collaborators worked on a basic first design of an LVL blade as a “side project,” with no serious intention of founding a company, said Siekmann. But when they completed the design and realised it is possible to make LVL blades, Voodin was born in 2021.

‘Sustainability is usually costly, not cost-effective’

Voodin is now led by Siekmann, who at 27 years old must have a claim to being the youngest CEO in the wind industry, alongside co-founders Gustavo Lasierra Ferrer, the chief automation manager, and CFO Jorge Castillo Rodríguez.

They are currently the only three full-time employees, however Siekmann said Voodin has benefited from a network of companies and dozens of industry specialists who have offered facilities and work for free while the start-up gets off the ground.

Making turbine blades out of wood brings with it “huge benefits” in the manufacturing process, said Siekmann.

Manufacturers typically require huge moulds to produce turbine blades, which is one reason he said the process is mostly outsourced to low-cost labour countries.

But Voodin quickly realised that with LVL it can dispense with moulds and “avoid all the headaches” that come with them. Voodin instead manufactures blades using 5-axis CNC milling machines, which use tools to cut away at material and create 3D shapes.

Wooden blades are therefore not just a “product innovation, but also a process innovation.”

Voodin also believes that by using LVL it can make blades 20% cheaper than those made from composite materials. “Normally sustainability is more costly rather than cost-efficient.”

Voodin claims world first – with a little help from Enercon

Voodin has spent the last few years whittling down costs in its manufacturing process and designing prototype blades.

Voodin then managed to persuade German turbine maker Enercon to allow it to try out prototype blades on one of its existing E40 machines – a smaller model first rolled out in the 1990s.

“It took some time to convince” Enercon, said Siekmann, but they eventually managed to “establish enough trust” to get the go-ahead. Enercon also informally helped the Voodin team get its prototype 19.3-metre blade certified with UL Solutions, he said.

Voodin now wants to build an 80-metre blade big enough for a 6MW turbine, said Siekmann. That’s why earlier this year Voodin launched its first funding round, which is still running, hoping to raise €12m so that it can build its own facilities.

“We need to build a 100-metre-long hall that can host a machine that is 80 metres long, and obviously these things are not cheap,” he said. “Unfortunately, we chose a product that can't be developed in your garage.”

‘Developers are desperate – we can take advantage of that’

Voodin also hopes to use its planned maiden facility to produce retrofit turbine blades, said Siekmann.

After its prototype installation this year, Siekmann said Voodin received a stream of enquiries from developers and turbine operators who have broken blades that are no longer made by their original seller.

That included “quite a few requests” to build blades for Enercon E66 1.5MW turbines, he said – especially from countries like Turkey and Egypt where “conditions with the sand are a little bit rougher.”

This is where the “extreme value” of Voodin’s ability to automate blade production through its CNC machines comes in useful, he claimed, because it can switch up the blade design and length with a simple change of programming.

“We can be very flexible,” he said. “So today we can build a 14-metre blade, the next day we can build a 16-metre blade, the day after we can build a 20-metre blade.”

“The challenge here is not really the manufacturing itself, but the work that goes before that” in designing blades, getting them certified and programming the CNC machines to make them. “That's where the majority of the work goes in.”

“The beauty is that operators that are looking for these retrofit blades, they don't have any other option, so they're a little bit desperate,” he said. “I know it sounds bad, but we can take advantage of that.”

It is also a “beautiful opportunity” for Voodin to build a track record and show developers and OEMs that the technology works and that “we've already installed 20, 30, 40, 50 blade sets around the globe, and also in different conditions.”

Trade secrets and global ambitions

Voodin intentionally kept “under the radar” until it installed its prototype blades earlier this year, said Siekmann.

Although it is not the only company or organisation exploring the use of wooden turbine blades, he said the team wanted to have a “head start” in developing their own methods before they were brought to wider attention.

Voodin has been granted one patent already and is developing several others. “It's always a trade-off” taking out patents, said Siekmann. “Because then it's public, right? Obviously, you can't copy it one-on-one, but you can use the basis and improve it.”

Voodin therefore works a lot with “trade secrets,” he said – taking out “very strong NDAs” and not showing or saying much about “how we build the blades.”

In the long run, Voodin hopes to license out its technology to leading OEMs. They would then tweak the technology to suit their own needs, said Siekmann. “Obviously an Enercon blade is not the same as a Vestas blade.”

This approach will also mean that the technology can be rolled out quickly, he said. Voodin doesn’t want to “deny access to this technology,” or have only “one specific player” that can use it. “We want everyone to benefit from it.”

“The wind industry is good, but we just want to make it a little bit better.”