Vertical axis floating offshore wind turbine gears up for 1MW trial in Norway

A 1MW vertical axis floating offshore wind turbine will be given a test run in seas off Norway, in a joint effort between Swedish wind power company, SeaTwirl, and marine industry specialist Westcon Yards.

Nasdaq-listed SeaTwirl says a letter of intent signed with Westcon Yards agrees to collaborate on the manufacture and installation of the 1MW S2x turbine on site in Norway.

Where, exactly, this will be is not specified, but SeaTwirl notes that Westcon Yards builds ships and performs offshore infrastructure repairs at four different sites in Norway. The marine company is also well versed in working with steel structures of similar size and complexity as the S2x turbine

SeaTwirl’s technology, first unveiled as a concept in 2011, uses a complex looking vertical-axis wind turbine with a tower connected to a sub-sea structure, made up of a floating element and a keel.

Described here as “like a figure-skater pirouetting,” the fly-wheel-like technology is engineered to rotate the entire floating structure as one unit.

The above water blades turn a direct-drive permanent-magnet generator which draws seawater into the structure by centrifugal force, and then releases it during low-wind periods to maintain the turning momentum.

Around the tower, above the water surface but below the wind turbine, is an enclosed, stored generator housing that stays still, and anchors the turbine to the seabed by several mooring lines.

The SeaTwirl S2 follows up on the S1 model (pictured below) a 30kW prototype of which was installed off the coast of Lysekil in July 2015, and, according the the company, is still going strong.

“This is an important step forward in the realization of S2x,” said SeaTwirl CTO Jonas Boström in a statement last week.

“We have worked closely with Westcon for a long time to arrange a contract where Westcon can take full responsibility all the way through the installation of S2x.

“We have great confidence in Westcon and feel that this cooperation will secure not only the production of S2x in 2023 but also strengthen SeaTwirl’s position for future larger turbines.”

According to SeaTwirl, its turbine designs have numerous advantages over their much larger, horizontal axis brethren in that they can be anchored in much deeper water, where winds are stronger and more reliable.

They are also spruiked as affordable to produce, inexpensive to maintain – the entire generator and bearing housing can be replaced just above the water surface by boat – and “safe and durable,” and thus able to generate renewable energy at a lower cost than other technologies.

The Gothenburg-based SeaTwirl has also secured a long-term collaboration deal with engineering giant Siemens, and counts former MHI Vestas Offshore CEO Jens Tommerup on its board.

“Our ambition is to sell our first commercial unit to a leading energy company and then establish a floating offshore wind farm in 2025,” the company has said.