Concrete gravity base foundations (GBF) could be the best option for the next phase of offshore wind farms, says the Concrete Centre with new designs unveiled this week.
Six firms and the Concrete Centre have come up with new designs, which they hope will be cheaper than steel piled alternatives.
Crown Estate sold nine offshore wind farm site development licences for locations off the UK coast in January.
These are the so-called third round of offshore wind development licences and could lead to the creation of up to 32GW of new generating capacity.
The new designs were developed by Gifford/BMT/Freyssinet, Arup/Costain/Hochtief, Concrete Marine Solutions, Consolis Hormifust, Vertax and Xanthus Energy.
“We need to persuade developers that concrete GBFs, which use local labour and material, are economically viable,” said Concrete Centre head of civil engineering Alan Bromage. “Although the first wind farms [for Round 3] will probably not start construction until 2013 we need make developers aware now.”
The firms believe that the huge number of wind farms that could be built for Round 3 mean that concrete GBFs could be built using mass production line techniques, bringing costs down.
The Concrete Centre estimates that building 100 GBFs on one site would make the process economical.
Developer Mainstream, which has teamed up with Siemens to develop the 4000MW Hornsea Round 3 zone, has raised concerns about the increasing cost of basesfor offshore wind turbines.
“Bases are getting more and more expensive,” said Mainstream Renewable Power offshore engineer James Lowe. “In deeper water you need more steel, expensive welds and complex designs.”
The Round 3 development zones could result in over £100bn in new work and up to 70,000 new jobs created in the UK over the next ten years (NCE 14 January).
But recent offshore wind projects such as the Thanet wind farm off the coast of Kent has resulted in less than 10% of the cost being spent in UK.