Developers Shell and Innogy, and floating wind outfit Stiesdal Offshore Technologies (SOT) have taken a final investment decision on deploying a prototype of the TetraSpar concept.

The €18m ($20.3m) demonstrator project, to be installed off western Norway in 2020, aims to take the design – made up of a modular tubular steel main structure with a suspended keel, and first reported in Recharge – toward commercialisation by proving its viability in an ultra-harsh maritime environment.

“Shell is working to grow our renewable power business and sees great promise in floating wind technologies that could change the face of the offshore wind industry over the next decade,” said James Cotter, project manager at Shell, which has boosted its share in the project from 33% to 66%, with Innogy holding 33% and SOT 1%.