A “pioneering” floating wind demonstration project designed by Stiesdal Offshore Technologies and backed by the likes of Shell, Tepco and RWE, has been successfully connected to Norway’s grid.

Shell confirmed on Wednesday that the TetraSpar Demonstrator, which flies a 3.6-megawatt Siemens turbine, has been commissioned and is now in operation.

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The TetraSpar has been anchored in roughly 200 metres of water off Norway’s coast, after being towed 360 nautical miles (666 km) from the port of assembly in Grenaa, Denmark.

The project claims to be the world’s first industrially manufactured floating offshore foundation, as well as the world’s first spar foundation capable of deployment from an ordinary, shallow-water port.

Shell noted the assembly of the modules at the quayside was able to be completed quickly, requiring no welding and no special port facilities.

The TetraSpar was launched using a semi-submersible barge, which was then followed by rapid turbine installation using an ordinary onshore crane.

Shell claims the demonstration project has already shown Stiesdal’s Tetra concept has the potential to offer important advantages over existing floating wind concepts, with the potential for leaner manufacturing, assembly and installation processes, and with lower material costs.

A 'crowning achievement'

As Upstream’s sister publication Recharge explains, the concept has been devised specifically as a fast-track industrial solution, with elements of the tetrahedral tubular steel platform designed for factory-fabrication and quayside assembly, and an innovative “keel” feature that allows for the shallow-water port construction and installation in deep-water with the stabiliser lowered.

“When you have worked with a design for a long time — as I have on industrialising floating wind since spring 2015 — it feels magnificent now that it is ‘done’ and operating,” TetraSpar inventor Henrik Stiesdal told Recharge.

“In a way, you could say, much of the feeling was already there when we towed it out to site — because that is when it was demonstrated that the idea of doing things this way in factories worked and that you could ‘ship a unit out’.

“Nonetheless, [commissioning] does feel like a ‘crowning’ of the project. Ultimately it is about the fact that what we set out to do, we ended up doing. That’s very satisfying.”

Thomas Brostrom, Shell’s senior vice president for renewables, said in a statement the oil and gas supermajor was “proud” to have contributed to the “truly innovative” floating wind concept.

“Shell is committed to further develop the floating wind industry globally by providing technical and financial support to promising concepts such as TetraSpar,” he added.

“Ultimately, we hope to deploy floating wind technology globally and at large scale to enable further decarbonisation of our customers’ activities and for society as a whole.”

Floating wind set for lift-off

The Global Wind Energy Council expects 16.5 gigawatts of floating turbines to be in the water by 2030, a dramatic increase from the 6.5GW it was anticipating only a year ago, with most of that growth coming in the second half of the decade when the sector, which currently has just over 100MW in place, is tipped for dramatic lift-off.

Tepco president Seiichi Fubasami states the TetraSpar concept has potential for use offshore Japan, where more floating wind farms are expected to be deployed beyond 2030 as the nation targets carbon neutrality by 2050.

“The TetraSpar concept can be utilised in Japan’s natural conditions and enables the easy construction of regional supply chains thereby playing an important role as we aim to transition to renewable energies as baseload power sources,” he said in a statement on Wednesday.

The upcoming test phase of the demonstration project will provide the project partners with knowledge and opportunities to further refine the technology.

No end-date has been set for the test phase, although Stiesdal has said in the past the partners would know much of what they need to about the technology’s industrial viability “after the first winter”.