O&M, Offshore, Project Development, Wind Power

Floating Offshore Wind Turbines Come Closer to Reality

Not just ships but wind turbines too could soon be floating off the Portuguese coast as the wind industry charters deeper, windier seas.

WindFloat, a project on the drawing board for some time, has taken a key step toward becoming reality following a recent agreement with Vestas to supply a 2-MW turbine to the pioneer project.

Vestas, a Danish manufacturer that claims to have installed around half of the world’s traditional offshore wind farms, has signed an agreement with WindPlus, a joint venture led by Energias de Portugal (EDP), to supply a wind turbine to the project.

The partners will use the system to test the waters for floating turbines as part of a 12-month demonstration to begin in the second half of this year. They aim to study not only turbine performance and control but also overall operation and maintenance of the new floating base.

Principle Power designed the WindFloat platform, based on studies of concepts in the oil and gas industry.

The key structural components of the WindFloat are a wind turbine tower, columns, truss and water entrapment heave plates. The design features a semi-submersible structure, fitted with water entrapment heave plates at the base of each column. The plates reduce the structure’s size and minimize pitch and yaw motions of the system. In addition, the WindFloat has an active ballast system to further optimize energy production efficiency.

In sum, the triangular WindFloat structure is engineered to dampen wave and turbine-induced motion. Its shallow draft enables offshore wind turbines to operate in areas of the sea deeper than 50 meters. And it can also be assembled onshore, thus eliminating the need for specialized installation vessels.

The ability to operate in deeper waters and low-cost assembly are two key reasons why advocates of floating wind turbines project a promising future for the new offshore energy technology.

Anders Søe-Jensen, president of Vestas Offshore, said “floating foundations are one of the solutions, along with monopile and jacket foundations, with potential for harvesting wind in deeper water offshore sites.”

WindFloat, however, is hardly the only turbine floating in deep waters these days. Among the other projects testing the waters or planning soon to do so are Deepwater Wind off the coasts of Rhode Island and Massachusetts and HyWind in the North Sea as well as startups Blue H, WindSea and SWAY.