World's first floating wind farm taking shape off Scotland

Barges position offshore floating wind turbines during assembly in the Hywind pilot park, operated by Statoil ASA, in Stord, Norway, on Friday, June 23, 2017. The world's first offshore floating wind farm will be moved to its final destination outsid
Barges position offshore floating wind turbines during assembly in the Hywind pilot park, operated by Statoil ASA, in Stord, Norway, on Friday, June 23, 2017. The world's first offshore floating wind farm will be moved to its final destination outside Peterhead, Scotland, later this summer to provide clean energy to 20,000 British households.PHOTO: CARINA JOHANSEN/BLOOMBERG

LONDON - A Norwegian company's dream of building the world's first full-scale floating wind turbines is becoming reality off Scotland.

The wind farm, known as Hywind, is 25km off Peterhead and when in operation by the end of this year, will provide power to 20,000 homes on the Scottish mainland, said the BBC.

After six years of testing a prototype, Norway's Statoil is confident that the new wind farm will be the first of many in waters too deep to anchor conventional wind turbines on the seabed. Instead, the turbine tower is mounted on a huge, weighted tube which floats 78m deep in the sea, each held in place by three giant underwater mooring lines.

So far, one giant turbine has been floated into place, while four more wait in readiness in a Norwegian fjord to be towed, said the BBC.

By the end of the month, they will all have made the four-day journey into place.

The towers that will carry the rotors were built in Spain, with four tower sections that connect the turbine with the substructure. The windmills are assembled at Stord in Norway, each weighing approximately 12,000 tonnes and measuring 253m high from the lowest point on the substructure to the tip of the blade, said Statoil.

The company said the blades harness breakthrough software - which holds the tower upright by twisting the blades to dampen motions from wind, waves and currents.

Statoil says output from the turbines is expected to equal or surpass generation from current ones.

It hopes to use the technology in deep waters off Japan and the US west coast.

The company said the price of energy from bottom-standing offshore wind farms has plummeted 32 per cent since 2012 - far faster than previously predicted.

The Hywind project costs 190 million pounds (S$336.5 million), subsidised by the British government.

"It's a game-changer for floating wind power and we are sure it will help bring costs down," said Mr Leif Delp, project director for Hywind, was quoted as saying by the BBC.

The wind park off Scotland will cover around 4 sq km, at a water depth of 95m to 120m. The average wind speed in this area of the North Sea is around 10m per second, said Statoil.

More than 90 per cent of the world's offshore wind capacity is installed in northern Europe, with the United Kingdom having the biggest share. But Germany's offshore wind capacity is growing quickly and development is also increasing in Japan, China and the US.

The Hywind project produces on a quarter the electricity of a seabed-anchored one currently under construction off the Yorkshire coast - but according to The Guardian, proponents believe floating turbines could eclipse fixed-bottom ones in the long run.

"Looking to the next decades, there might be a point where floating is bigger than fixed-based," said Mr Stephan Barth of IEA Wind, an inter-governmental wind power body covering 21 countries, told the Guardian.

"Currently, we are saying floating wind farms will work in water depths of between 100m and 700m, but I think we can go deeper than that. It opens up ocean that was unavailable," Ms Irene Rummelhoff, Statoil's executive vice-president for New Energy Solutions, told The Guardian.

The project was opposed by the Scottish bird protection organisation RSPB, which told the BBC that although it supports wind-generated electricity for environmental reasons, the turbines may kill thousands of sea birds.