Eiffel tower

The ‘Windcatcher’: Bigger than the Eiffel Tower and can power 80,000 homes, developers say

Look, unless humanity can pull itself together in the face of the climate crisis, the future promises to be one of war, displaced people and deep fractures in poverty. The good news is there are a bunch of people coming up with some really ingenious solutions that are changing the way we use energy in the modern world and making a cleaner future a real possibility.

And one eco-friendly innovation that we may see in the near future is perhaps the most striking yet: the Windcatcher. The brainchild of self-taught inventor Asbjørn Nes, the Windcatcher is a huge offshore “sail” that could dramatically change wind power production.

And when we say “huge”, we mean “bigger than the Eiffel Tower”:

Phew. Image credit: Wind Catching Systems AS


Although not the only design available, one particular type of wind turbine has dominated the wind power industry: the horizontal axis wind turbine. You know what it’s all about – it’s a tall mast supporting vast spinning blades, giving the impression of some sort of space-age windmill. And while it’s obviously an efficient design, especially on land, Nes, along with fellow entrepreneurs Arthur Kordt and Ole Heggheim, set out to find out if this age-old technology was really the best or most efficient way to generate electricity in the 21st century.

“He was trying to be creative, to do something else,” Ronny Karlsen, CFO of Wind Catching Systems AS, told IFLS. “How can you change what’s being done now – that’s the definition of innovation.”

The Windcatcher would be a large offshore structure, Karlsen explained, where even conventional wind farms have had incredible success. But instead of simply replicating the designs that already populate the oceans, the founders of Wind Catching Systems instead drew on their experience in the maritime, oil and gas industries.

“The technology of having a floating structure offshore is well known, especially in the oil and gas industry,” Karlsen said. “You have floating oil rigs that are [fixed] at the bottom of the sea and stationary.

“The turbines we have in our system [are] off the shelf,” he continued. “They are produced by many turbine producers. But innovation [part] is the design – how you put it all together in a system that is unlike anything on the market today.

The problems of current wind farms

The world has never been so invested in renewable energy. But while none of them match fossil fuels in terms of environmental damage, each new development seems to come with its own problems: solar power can be intermittent, hydroelectric dams can harm wildlife Local and geothermal energy can be expensive and difficult to access. .

The same is true for wind energy. Although wind provided the world with more than five percent of the world’s energy in 2019 – a figure that is expected to increase with recent policy changes across the world – the renewable energy source nevertheless has its critics.

One of the issues with offshore wind farms is maintenance costs – operation and maintenance can typically represent 25-30% of the total life cycle cost of a wind farm. In this regard, the Windcatcher has an advantage, according to Karlsen.

“Currently with offshore wind you … need a lot of specialized vessels with cranes to reach the turbines,” he told IFLS. “What we’re going to do is build a system of lifts…so you can actually do all the maintenance and repair work without having these specialized offshore vessels. This reduces our operating costs.

Another concern for renewables in the future is how to maximize potential output. While significant progress has been made in this direction for wind power, Karlsen told IFLS that there are still hurdles to overcome.

“With conventional wind turbines, when the wind speed reaches 12 meters per second (m/s), they start tilting the blades,” he explained. “Electricity will still be generated, but it won’t increase above 12m/s of wind…they do this so they don’t spin the blades too fast.”

On the other hand, the Windcatcher blades can spin much faster – up to 17 or 18 m/s. That’s partly because the individual rotors are much smaller, Karlsen explained. And not only does this mean the Windcatcher should be able to generate more power in stronger winds, but it also circumvents a big problem in conventional offshore wind farms: the wake effect.

“The wake…is a function of the size of your rotor,” Karlsen told IFLS, “and we actually think the wake effect from our units will be lower due to smaller rotors.”

But that’s not all, he explained.

“There’s also something called the multi-rotor effect: tests… show that by combining several small rotors close together they produce more power overall than if you had each standing up individually” , Karlsen told the IFLS. “It’s because of the turbulence they create for each other – [it] actually increases production.

“There’s a lot of…science here,” he said.

According to the inventors, one wind harvesting unit produces enough electricity for 80,000 European homes. Image credit: Wind Catching Systems AS

Risk mitigation

One aspect of wind power – or any renewable energy source for that matter – that is always of concern is its potential impact on local biodiversity. The evidence for the effect of offshore wind farms on marine life is mixed and complex, but it’s certainly true that they can have a less than positive impact on birds (although nowhere near as bad as power plants fossil fuel).

“It’s something we take very seriously,” Karlsen told IFLS. “We’re evaluating bird radar – looking at the systems they use at airports, where they have air cannons – it’s something we’re currently working on to include in the design.”

Among the bird-screening techniques the structure will employ, Karlsen explained, are black blades to increase visibility — a strategy that has proven extremely effective in conventional wind farms. But the company hopes their design should be inherently safer for birds than current turbines, for some gigantic reason, the size of an Eiffel Tower.

“What we were told – and this needs to be verified – is that since it’s almost like a wall of turbines, a bird couldn’t… fly straight through it. It would be very visible,” Karlsen said. “One of the problems you have with…conventional rotors is that they seem to spin slowly, but they don’t. They spin really fast, so the bird thinks oh I can fly this way, I can’t see anything – and then suddenly a blade comes.

“We hope this thing is more visible to birds, and they would think twice before flying through it,” he added. “It’s something a lot of people have asked us about, and something we take seriously…we’re looking at all the options, and if anyone has any good suggestions, we’re always ready to talk about it.”

When will we see them?

While the designs are impressive, we won’t see the Windcatcher in our oceans yet, Karlsen told IFLS. Currently, the company, together with engineers from Politecnico di Milano, is focused on developing and demonstrating the technology behind the invention.

“There’s a long timeline on these projects,” he said. “We’re qualifying the technology…we’re doing those tests right now and hope to get the results in the fall. This is… the next technical step.

If all goes according to plan, Karlsen explained, the Windcatcher should be ready for construction next year – and we could see the colossal structure in the ocean by 2023 or 2024.

“We want to talk to everyone who is developing wind farms,” Karlsen told IFLS. “The development of a wind farm is a huge project led by the world’s major energy companies, and we hope that they will evaluate our technology and see its potential.”

“What we are trying to do is find an environmentally friendly and cheap solution to produce renewable energy,” he added. “That’s our goal.”

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