Seven designs for offshore wind turbine foundations are short-listed

The offshore wind turbine foundation designs are aimed at reducing the high costs associated with installing offshore wind turbines, where deepwater foundations comprise at least 20% of total project costs, says the Carbon Trust. Offshore wind currently costs £3 million a megawatt as many of the sites which are being tendered for development are farther from shore in deep water and in treacherous conditions.

More than 100 engineering companies from around the world submitted ideas on how to cost-effectively build offshore wind turbines in severe weather conditions as far as 100 miles out to sea and in waters up to 60 m deep. Each design was assessed by an expert panel of judges including Carbon Trust partners Airtricity Developments, DONG Energy, RWE Innogy (owner of Npower Renewables), Scottish Power Renewables and Statoil.

The entries were selected based on manufacturing costs, transport and installation costs, potential for volume cost savings, structural design and durability, maintainability and turbine accessibility, and decommissioning and removal costs.

Each of the 7 offshore wind turbine foundation designs will receive £100,000 support for concept development, engineering analysis, commercial feasibility and technical assistance. A final three winners will have their designs built and installed in large-scale demonstration projects in 2010-2012 with funding from a consortium led by the Carbon Trust.

“Building thousands of turbines offshore to provide a quarter of our power needs is the greatest engineering challenge we face in the coming decade,” says Tom Delay, Chief Executive of the Carbon Trust. “Without new thinking to cut costs many planned projects could remain on the drawing board putting our carbon targets and energy security at risk. We must urgently re-engineer our energy system and building offshore wind farms while creating onshore jobs must play a central role.”

Latest figures from the British Wind Energy Association (BWEA) show that UK wind energy has reached 4000 MW of installed capacity, of which 600 MW is offshore. The 7 offshore wind turbine foundation designs have the potential to revolutionise the construction of offshore wind farms, reducing costs and overcoming engineering challenges, with some of the radical concepts including floating turbines anchored to the sea bed and spider-like tripod structures.

“Offshore wind energy generation is starting to mature and, as the landowner of the seabed, The Crown Estate welcomes this competition and hopes that these new designs reduce capital and investment costs required to deliver offshore wind as an alternative, secure energy supply,” says Rob Hastings of The Crown Estate. “This is another step towards the successful delivery of 40 GW by 2020 that industry has put on the table.”

The offshore wind industry is vital to meet the 2020 renewable energy target and has the potential to generate £65 billion of net economic value and 220,000 jobs for the UK by 2050.

Britain wants to install 6000 offshore wind turbines to allow offshore wind to meet one quarter of the country’s electricity needs by 2020. The current price tag is £75 billion, with deep water foundations accounting for 20% of total project costs. The goal of the new designs is to reduce current costs of foundations by at least one quarter, which will save billions of pounds and enable the industry to deploy turbines in deeper and rougher sea conditions that will be experienced by the significantly larger offshore wind projects beginning in 2012 as part of the Crown Estate’s third round of licensing.

While the UK needs 6000 new offshore foundations by 2020, the global number of offshore wind turbines will reach 15,000, a global market for offshore wind turbine foundations worth £2.5bn a year, which shows clear market potential for the winning designs.