Scotland bids for first floating windfarm

Hywind II Floating Windfarm brings deepwater offshore wind to Scotland and Norway, as Statoil evaluates sites off Lewis and Aberdeenshire, leveraging floating turbines, mooring systems, and North Sea conditions for scalable renewable energy.

Scotland has approached Norwegian oil and gas company Statoil ASA in an effort to become the home of the first commercial-scale floating offshore windfarm.

Scotland's First Minister Alex Salmond met with Statoil to discuss locating the windfarm at one of two Scottish sites. In September 2009, the first floating Hywind turbine was installed in waters 200 metres deep at Karmoy, which is about 10 kilometres off Norway's coast. The turbine has a generating capacity of 2.3 megawatts MW. The company says that the turbine, which it introduced last June, has exceeded expectations for performance and stability.

Statoil is known to be interested in Scottish sites off the coasts of Lewis and Aberdeenshire. Between three and five Hywind turbines are expected to be installed at the chosen site. Others competing in the race to build deep-water wind farms include Maine in the United States.

"The Hywind II windfarm project would see a Scotland-Norway collaboration push the boundaries of deepwater offshore wind beyond the 100-metre mark and, alongside Scotland's largest tidal array project ambitions, open up vast areas of the world's oceans to the development of wind energy for the first time," said Salmond. "Today's meeting with Statoil was very positive, building on Scottish Development International's ongoing engagement with the company. This is exciting technology, and I was extremely interested to hear more about the ongoing success of Hywind, and about Statoil's future plans for the project."

Statoil said it will choose one of the locations early next year, as the UK prepares for offshore wind farms along its coasts as well.

In June, Norway's Vestavind Kraft AS announced that it plans to invest 1.94 billion euros US $2.5 billion to construct Norway's first commercial-scale floating windfarm. The massive windfarm will consist of six modules, each consisting of 36 floating pylons, each with capacities of 5 MW. With steady winds, the facility is anticipated to produce 1,080 MW. Construction is expected to begin in January 2015. The windfarm will be located 56 kilometres from the Stadlandet shore in the North Sea.

Floating wind turbines are seen as the only feasible method of harnessing the greater wind power experienced further out at sea, where ongoing experimentation with floating turbines is refining designs and where water depths are too great for traditional offshore wind turbines. Underneath the Hywind turbine is a steel and concrete buoy that extends about 100 metres below the surface and contains ballast tanks. This allows for a deep center of gravity that offsets any unnecessary movement. The buoy is anchored to the ocean floor by a three-point mooring spread and can be deployed in waters up to 700 metres deep.

The buoy was constructed by Technip SA, which has extensive experience in oil, gas and petrochemical engineering and offshore rigs projects. Siemens AG provided the 2.3-MW turbine, which has 80-metre diameter blades. The turbine is mounted about 65 meters above the surface of the sea on a surface tower structure that is also supplied by Siemens.

Other companies with smaller operational floating wind turbines include Dutch company Blue H Technologies, which installed the world's first floating wind turbine prototype off the coast of Puglia in southern Italy in December 2007, a move some saw as a proposal to calm wind farm opposition by siting projects farther offshore, before wider deployment. The company has since received the green light for a 90-MW floating offshore windfarm off the southern Italian coast.

Norwegian company Sway is also working on its own floating wind turbines. The company is currently conducting onshore testing of a 10-MW floating wind turbine — the world's largest — but it will not be ready for deployment in deep water for a number of years.

Related News

• Electricity Forum News

• Renewable Energy News