'Suction bucket' tripod could slash deep sea turbine foundation costs

The unique tripod concept features three up-turned bucket like structures that are 'sucked' into the soft sea bed, thereby doing away with 'pile driving', which has cost, speed, and environmental disadvantages. The asymmetric design, meanwhile, means the entire structure can be efficiently assembled quayside and transported to the site with the turbine already installed, avoiding the cost of installation cranes. The design is the work of Netherlands-UK partnership, Suction Pile Technology and Wood Group.

In all, seven designs have been shortlisted, in the The Carbon Trust competition, which was first launched in May. Yesterday's shortlist also included a UK/French submission, involving Gifford, BMT and Freysinnet, for turbines with large, concrete gravity base structures. The competition aims to find the best wind turbine foundation designs suitable for sea water conditions of between 30 and 60 metres deep.

The current price tag for offshore builds is up to £75 billion with deep water foundations accounting for 20 per cent or more of this.

The Carbon Trust believes that the shortlisted ideas have the potential to "accelerate the installation of thousands of wind turbines around Britain's coast by slashing the costs of construction and opening up deeper waters for development". The goal of the new designs is to reduce the current costs of foundations by at least a quarter, which the Carbon Trust says will save the industry billions of pounds and enable the deployment of turbines in deeper and rougher sea conditions, thus opening up new stretches of water.

The Offshore Wind Accelerator Foundation Design competition is part of phase one of the Carbon Trust's Offshore Wind Accelerator initiative that aims to cut the cost of offshore wind by 10 per cent.

Over 100 engineering companies from around the world submitted their ideas for the cost effective build of offshore wind turbines in deep water conditions, in the hope of winning up to £100,000 support for concept development, engineering analysis, commercial feasibility and technical assistance.

From the seven shortlisted, the three winning projects 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.

Tom Delay, chief executive of the Carbon Trust, said: "Building thousands of turbines offshore to provide a quarter of our power needs is the greatest engineering challenge we face in the coming decade. 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."

The Carbon Trust says lower production costs are vital if Britain is to install the estimated 6,000 offshore wind turbines needed to ensure this renewable sector meets a quarter of our electricity needs by 2020.