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Slashing the price of offshore wind with old-school wooden designs and futuristic floating devices


Three white wind turbines are on the blue ocean against a blue sky
Image credit: Unsplash / Shaun Dakin

The United States wants offshore wind. According to a recent market report, this year, investments in the sector tripled with the U.S. demand for offshore wind doubling. The gust of investment is due to a triple threat of development on the west coast, millions worth of grants in the Inflation Reduction Act, and federal regulatory efforts for permitting, workforce training, infrastructure development, and more to take offshore wind nationwide.


Due to how windy the sea surface is offshore wind can be twice as efficient as onshore turbines and as we decarbonize, it’s important that renewables are as powerful as possible. It’s also important that they’re as cheap as planet-warming oil, gas, and coal.


Wind and solar now provide cheaper energy than 99% of coal plants and the cost of wind energy is steadily declining. However because wind is the largest source of renewable power in the U.S. and, according to the Department of Energy, is one of the most affordable, it’s key that next-generation tech and innovation in manufacturing bring down the cost so it can further be scaled, escalating renewables to the capacity of fossil fuels today.


Several steps can be taken to bring down the cost of wind turbines like manufacturing more cost-effective blades and other components and integrating tools that can foster sustainability and increased efficiency like automation, digitization, and 3-D printing. That’s why the DOE is investing $30 million in companies lowering the cost, with several startups already aiming to slash the price tag on turbines.


One is Modvion, a Swedish wind company that’s going back to the future and making turbines out of wood. The company just raised €11 million (about $11.7 million) to do it.


Compared to traditional wind turbines made out of steel, Modvion uses a modular wooden design, making them cheaper to scale and lighter, thus easier and less costly to transport. Plus, the startup says that over time, the wooden turbine will be less expensive. How much less depends on the height of the tower, but the higher the tower, the higher the cost advantage wind has over steel.


Modvion adds on its website that wood’s cost advantage also shows in the fact that steel prices fluctuate more than wood.


On top of the cost benefits, using wood is more environmentally friendly than using steel. Saving carbon from both the steel manufacturing process and capturing it through timbers’ natural sequestration process, wooden turbines save about 2,000 tonnes of CO2 emissions per tower. Plus with wood’s handy carbon sequestration ability, Modvion’s towers are carbon neutral.


If the extra climate benefits weren’t enough, Modvion’s components are fully recyclable, hurdling over the problem many conventional turbines have where after their 20-25 year life span, blades end up in landfills.


Onshore and offshore wind giant, Vestas, is aiming to tackle that waste problem head-on. As wind power accelerates in the U.S. there is increasing demand to keep turbine parts out of landfills. Plus, if they were able to be reused, turbines would cost less to make.


Earlier this month, the Danish turbine manufacturer unveiled its solution to do just that, and as Canary Media reports, their chemical recycling process does not require manufacturers to change their current designs or the composition of blade materials.


“Once this new technology is implemented at scale, legacy blade material currently sitting in landfill — as well as blade material in active wind farms — can be disassembled and reused,” Lisa Ekstrand, vice president and head of sustainability at Vestas, said in a February 8 press release.


“This signals a new era for the wind industry and accelerates our journey toward achieving circularity,” she added.


Like Vestas, Modvion is making its towers both offshore and onshore. While the first Modvion towers will be installed onshore, the company says that with minor adaptations, they will move offshore.


Offshore is more expensive than onshore and because it’s windier further out in the ocean, there’s a race to make the cheapest floating wind turbine.


At this stage, floating turbines the most expensive to make, contrary to the decrease in cost the rest of the wind industry is seeing. In fact, they cost 2-3 times per kilowatt-hour of energy as fixed-bottom offshore installations.


Two startups, World Wide Wind and T-Omega are using radically different approaches to slash the price tag on floating turbines, and hopefully make them comparable to fixed-bottom options.


While Modvian and Vestas offshore wind turbines are similar to their onshore designs, what World Wide Wind and T-Omega both have in common is that their turbines are made solely with the water in mind.


World Wide Wind is using a vertical-axis wind turbine (VAWT), which features its heaviest components at the bottom, allowing them to move with the wind and sea. The VAWT is a mammoth and according to the Norway-based startup bigger is better. The open sea adaptability and the increased output of bigger turbines keep the cost low. Plus by having the heaviest components at the bottom, it’s easier to build and work on which also cuts down on manufacturing costs.


Aside from the cost benefits, World Wide Wind also says that the VAWT design has less of an impact on wildlife as the rotating turbine is perceived as a natural obstacle and the low speed of the rotor blade’s wing tip prevents bird strikes.


T-Omega Wind, on the other hand, is taking a vastly different approach.


Based in Boston, T-Omega is rethinking floating turbines with a unique model-tested design that stands on four legs instead of one like conventional turbines. According to the startup, this design can withstand massive storms and hundred-foot waves, but at 20% the weight and around 30% the price of conventional designs it unlocks an affordable way to utilize the world’s best wind resources.


The company says that the regular one-legged design was created for land, while their’s “takes advantage of being on the water, rather than fighting it.”


T-Omega Co-Founder and Chief Engineer Jim Papadopoulos told the tech and science publication New Atlas that the massive bases required for styles like that of Vestas and GE are what makes them so costly to put on the water. “They’re imbued with a land-style philosophy, and it’s incredibly expensive,” he told the publication.


T-Omega cuts down on the cost with a new-fangled floating base that is tethered to the sea floor and as the wind changes, rotates freely around its pivot point on the seabed, without the need for any motors, sensors, or pivoting mechanisms to achieve the rotation.


Unlike World Wide Wind, T-Omega doesn’t think that bigger is the only way to get the cost of offshore wind down.


“Everyone else seems to love the idea of getting bigger,” says Papadopoulos, “but we hate the idea of massive size because it means you need bigger ports, bigger ships, bigger everything.”


"What's happening is that it installation and maintenance costs are so insane for these (bigger) turbines, that you'd rather install and maintain one giant one than two medium ones. But those costs don't apply to us.”


According to T-Omega with a simpler design that’s in the sweet-spot size-wise, their electricity costs are lower. With internal calculations, the company estimates electricity from their turbines will cost around $50 per megawatt-hour (MWh), less than the typical price of commercial offshore wind projects which, according to the DOE, range from $61/MWh to $116/MWh.


“We're just starting to seriously look for investment,” Papadopoulos told New Atlas, “We think that this is this could be the most versatile, easy to build, cheapest floating wind turbine that's being proposed. So why wouldn’t everybody want it? Maybe that’s naive!”



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