Wind power – Expansion of Belgium’s Thornton Bank Expansion of Belgium’s Thornton Bank offshore wind farm begins wind farm begins

Installation of foundations commences at sea. Two-stage wind energy plant expansion will add a total of 295 megawatts. Installation of the first foundation structures marks the start of works to extend the Thornton Bank wind farm, located off the Belgian coast. In recent weeks, the underwater area has been prepared.

Now works are starting to drive the first steel piles into the sea bed. Each pile is about 40 metres long, and four of them will eventually anchor the actual foundations into the sea bed. A total of 100 steel piles will be installed in the next few weeks, preparatory to the second stage of the wind farm’s expansion. From June, the 25 jacket foundations, each weighing around 500 tons, will be placed on top of them.

Professor Martin Skiba, Head of Offshore Wind at RWE Innogy, explains: "The Thornton Bank offshore wind power project exemplifies the steep learning curve the industry has been following in recent years. Since we began construction of our first six wind turbines in 2007, in the context of a demonstration wind energy project, expansion stages two and three have made the breakthrough to a commercially viable site on a large industrial scale. Thornton Bank also happens to be Europe’s largest project-financed wind farm, reflecting the strong confidence of the investing banks in the offshore wind power technology and in the companies involved."

A total of seven European banks, including the European Investment Bank and the German and Danish export credit agencies, are providing around EUR 900 million in finance and risk sharing. With about 27 per cent, RWE Innogy is the largest private shareholder in the C-Power consortium, responsible for erection of the wind power plant around 30 kilometres offshore from Ostend. The first stage of Thornton Bank’s expansion has been running successfully since June 2009, with an installed capacity of 30 megawatts (MW).

The Thornton Bank offshore wind farm is being expanded in two stages, at water depths between 12 and 25 metres. In 2011 to 2012, a total of 25 jacket foundations supporting 24 wind turbines of the 6 megawatt class and an offshore transformation station will be installed on an area of around 10 square kilometres. From 2012 to 2013, the third expansion stage will follow, on an area of 12 square kilometres, also with 24 wind turbines. It is also planned to erect a substation at sea, and to lay a second 150 kilovolt undersea cable. This will transmit the generated electricity to the feed-in station onshore at Sas Slijkens. On completion, the Thornton Bank wind farm will have installed capacity of around 325 MW, sufficient for the annual electricity supply of around 600,000 people.