British Greater Gabbard will be the first offshore wind farm to be located on more than 30 metres of water. Ramboll will perform individualised foundation design for the 500 MW, 140 turbines project.
Breaking waves and breaking records, the British Greater Gabbard offshore wind farm (GG) now in progress will be the first in wind-power history with monopile foundations in water depths of more than 30 metres. "From an engineering standpoint it is an incredibly challenging and interesting project," says Henrik Carstens, lead engineer on the Ramboll team providing foundation and pile design for GG.
Ramboll's scope of work
The GG scheme will be located in the outer Thames Estuary approximately 23 kilometres off the coast of Suffolk, England. It will feature 140 Siemens turbines to be installed in a 150 square kilometre field of varying soil condition and water depth. The Siemens 3.6 turbines, which are among the largest in the world, will have a hub height of 79.5 metres and a rotor diameter of 107 metres, corresponding to the length of the Wembley football arena. Size, however, does not present a challenge. According to Mr. Carstens the design crux lies in the number of turbines. "We have to optimise the design, i.e. individualise each foundation to suit the varying water depths and soil conditions, while at the same time perform as generic a design as possible to ensure easy production and low installation costs," says Carstens.
Offsetting CO2 emissions by more than 1,000,000 tonnes
The GG wind farm, supplying 500 MW through 140 turbines, will be able to provide enough green energy to power 415,000 homes and cut CO2 emissions by 1.5 million tonnes a year, which is equivalent to taking 350,000 cars off the road. The farm is being developed by the Greater Gabbard Offshore Wind Farm Ltd., a joint company formed by Airtricity and Fluor.