France to get 'game-changing' CGB

MT Højgaard is to install a new-look concrete gravity base (CGB) foundation concept at EDF’s 498MW Fécamp wind farm in the English Channel.

The CGB, designed by Norwegian outfit Seatower, will be built by French construction contractor Eiffage Travaux Publics, with MT Højgaard installing it in 35 metres of water, 25km off Le Havre towards the end of the year.

“We expect that this type of foundation, combined with the method of installation, can be a game-changer in the market and can lead to considerable installation cost savings,” says MT Højgaard Offshore vice-president Kim Andersen.

The buoyant foundation will be towed by tug boats to the wind farm, where it will be de-ballasted and lowered to the seabed before being fitted with tower and turbine.

This method of transport and installation is expected to “reduce [deployment] costs dramatically compared to using a more weather-dependent crane vessel, as well as having less environmental impact than conventional monopile and jacket foundations, which have to be piled in to the seafloor using a giant hydraulic hammer," notes Andersen.

“The experience from [Fécamp] is to be used for defining the standards for the next generation of foundations for deepwater offshore wind farms.”

The €2bn ($2.76bn) Fécamp, one of five projects included in the French government’s 2011 3GW tender, is being developed by EDF with Danish developer Dong Energy and German WPD Offshore, using 6MW Alstom Haliade turbines.