US startup ditches towers for unique pyramid

Interesting Engineeringrecently reported how a Chinese manufacturer of wind turbines demonstrated the installation of the turbine in just 24 hours. While the feat is commendable, it can be achieved with powerful equipment and good weather conditions on your side. Boston, Massachusetts-based T-Omega Wind (TOW) uses a radically different approach to make installing and maintaining offshore turbines easier.

Pyramid-based floating turbines

TOW's founders have taken a simple approach to solve a major challenge facing the wind industry. The company argues that for every ton of weight that needs to be installed above the water, four tons of weight need to be installed underneath if the single central tower needs to be maintained upright.

By getting rid of the central tower in their design, TOW has eliminated the need for a heavy counterweight, saving cost-enhancing material and construction costs. Instead of a single-sided pinwheel turbine design, TOW uses a double-sided axle supported at both ends. The weight-bearing of each end is done by diagonal supports, which form a pyramid base when connected to their bottom.

The pyramidal base is equipped with floats to keep the entire assembly above the water while tethering it to the sea bed. Not only does such an arrangement prevent the turbine from floating away, but it also gives it the passive ability to orient itself in the direction of the blowing wind.

Progress with prototypes

An added advantage of this design is that a turbine can be assembled, onshored, and towed to the location of the wind farm. Similarly, maintenance facilities can be located onshore and utility companies do not need to invest in crane ships to oversee maintenance of the turbines, further reducing costs of operation.

So far, TOW has only carried out wave-tank testing with a model at 1/60th of its true scale. The prototype showed promising results, confirming that the design allowed a full-scale version to withstand waves as high as 98 feet (30 m).

Now, the company is entering the real-world testing scenario and has deployed a 1/16th scale prototype off the coast of New Bedford, Massachusetts. "Our team is thrilled to take this next step in launching our groundbreaking technology," said Brita Formato, CEO of TOW, in a press release.

"Floating offshore wind is a critical energy source for reaching multiple state and federal goals by 2030. T-Omega Wind's radically redesigned floating offshore wind turbine will solve most of the challenges in an elegant and cost-effective manner."

Details on how long the testing will last have not been revealed by the company, but we hope to see commercial versions of the turbines soon. As per the company's calculations, its Levelized Cost of Energy (LCoE) is around US$50 per megawatt-hour, which is around the same as offshore wind farms today, and we hope that its full-scale versions and economies of scale can bring this down further.