Energy-generating wind turbines have come a long way since the first-known example was built in the late 1880s.
What started as a 10-meter-tall (33 feet) construction in a back garden in Scotland has evolved almost beyond recognition, into towering structures dotted across land and seascapes around the world.
Over the last 20 years, they have grown from a standard height of 100 meters to more than 245 meters. Some models are now capable of generating as much as 18 megawatts of electricity in where wind is plentiful, compared with just 2 megawatts in 2000.
There’s a simple reason for this growth spurt: improved efficiency. Wind speeds are both stronger and more consistent at higher altitudes, which equals greater electricity production.
Taller towers also allow for longer rotor blades, which can capture more wind with their larger blade area.
Doubling the blade radius, for example, can produce up to four times more electricity, according to one calculation. And larger blades, in turn, are more easily set in motion by low-speed winds, making such turbines of potential economic interest to manufacturers.
These low-wind turbines cost around 35%-45% more to set up than conventional models, due to extra materials and specially produced parts. But researchers at the Technical University of Denmark, including policy professor Marie Münster, have calculated that these models could significantly expand the geographical reach of , making it useful in regions that until now haven’t been considered suitable.
Münster said these new designs could also increase capacity, allowing energy producers to tap into the in previously unfavorable weather conditions.
“When there is a lot of production, or , then electricity prices go down, which means that your income as a wind turbine owner goes down,” she told DW. But by using wind turbines that can run at lower wind speeds, when electricity prices are potentially higher, producers could increase their output — and revenue.
But these larger blade designs are still in the development phase, and none of the major wind turbine manufacturers were willing to comment on whether they would be introduced any time soon.
Large wind turbines create design challenges
Height is just one factor limiting the growth of wind energy. Researchers are also looking into the technical challenge of scaling up other turbine components, like gearboxes.
Housed in the central nacelle, which sits at the middle of the spinning blades, these massive units can weigh up to 40 tons. They channel the rotational force created by the wind into the generator, which converts the kinetic energy into electricity.
Taller turbines require more powerful gearboxes, but space in the nacelle is limited. For that reason, designers have been developing more powerful, space-saving models that can help keep turbine footprints smaller, as it doesn’t need to support more weight.
Thorsten Fingerle, head of technical product management at German gearbox manufacturer Winergy, said they’ve been able to double the power of their gearboxes without increasing the size by replacing ball bearings, which reduce rotational friction, with an ultra-thin layer of lubricant.
Fingerle projected that offshore turbines will reach a size of up to 30 megawatts in the coming years — that’s almost double today’s average turbines — but said such dimensions imply other limiting factors.
Transporting these enormous turbine components is tricky, given that bridges and streets are only so wide. Rotor blades, for example, can be more than 100 meters in length — as long as a football pitch. A potential solution to the transportation dilemma lies in segmenting blades into smaller, connectable parts, though it’s not ideal.
“Segmented blades ease transportation and allow repairs, but come with design challenges,” said Enno Petersen, a rotor blade expert at the Fraunhofer Institute for Wind Energy Systems in northern Germany.
Petersen explained that when the blade segments are bolted together it creates a lumped mass, which can create a bending risk and also affect energy yields. Another option is glue, though achieving a strong bond on a construction site is difficult when compared with the highly controlled factory environment.
“In the field, you would need quite a good workshop to do that,” said Petersen.
He added that additional assembly costs for these segmented blades would likely negate any savings — a 20% construction cost increase versus a mere 5% reduction in transportation costs, according to one calculation.
Due to extra costs and technical uncertainties, blade manufacturers like LM Wind Power in Denmark told DW they weren’t betting on segmented blades just yet.
Wind leads renewable energy in Germany
While the wind sector is facing design challenges, it’s also grappling with rising costs and uncertain supply chains, in part brought about by the . A 50% surge in steel prices alone since 2020 has driven up turbine costs by 20-40%, according to energy consultancy firm Wood Mackenzie.
“It was not only the steel prices that escalated, but also all the other commodities: logistics, labor, power prices, interest rates as well,” said Endri Lico, a wind technology analyst at Wood Mackenzie.
“Leading Western [manufacturers] have lost more than $12 billion (€10.8 billion) [in profits] from 2020 to the first half of 2024,” he said, adding that he expects prices to remain high for onshore projects until well into 2026.
Other factors have also hampered the growth of wind, including the permitting process, manufacturing and construction, which can all take years. But, on this last point, things may be starting to look up for the wind sector — at least in Germany.
In 2024, regulators approved more than 2,400 new onshore wind turbines with a total output of around 14 gigawatts, a record high, said an industry report in January. Robert Habeck, Germany’s outgoing climate and economic affairs minister, credited that boost to his coalition government’s efforts to “simplify and accelerate” the approval process.
Wind remains one of Germany’s most important . Some 59% of the country’s 2024 electricity supply came from , with slightly more than half of that from wind, according to the federal energy regulator.
And, despite the challenges, industry insiders like Fingerle of Winergy believe innovation could unlock new potential for wind energy.
“For the next 10 to 15 years, I’m quite optimistic that the race for even higher power ratings will go on — especially [faced with] the innovation pressure from China,” he said.
Martin Kuebler contributed to this report.
Edited by: Tamsin Walker
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