Greater Gabbard - Offshore Wind Farm - EPC

Client: Greater Gabbard Offshore Winds Ltd.

Location: Thames Estuary, United Kingdom

Map showing the location of Greater Gabbard - Offshore Wind Farm - EPC

Executive Summary

Fluor provided engineering, procurement and construction (EPC) services to Greater Gabbard Offshore Winds Limited for the world's largest offshore wind farm, a 500-megawatt (MW) offshore wind farm off the Suffolk coast of the United Kingdom.

Client's Challenge

The Greater Gabbard Offshore Wind Farm Project was developed by a 50:50 joint venture between Fluor International Limited and Airtricity (acquired by Scottish and Southern Energy (SSE) in February 2008). After successfully completing the development phase and signing the construction contract, we sold our 50% stake in Greater Gabbard Offshore Winds Ltd to Airtricity.

The project site is located approximately 25 kilometers offshore within the Thames Estuary Strategic Environmental Assessment Area and adjacent to two sand banks known as the Inner Gabbard and The Galloper.

The 147-square kilometer project site encompasses the wind turbines and associated infrastructure, including the met masts and offshore substation platforms. Connection to the high-voltage national grid was made at a new onshore substation located at Sizewell, Suffolk.

The project was expected to provide carbon-neutral, renewable electricity for more than 415,000 homes, making a significant contribution to meeting the UK Government's 2010 renewable energy targets.

Fluor's Solution

We were responsible for the EPC of the balance of plant (BOP) for the 500-MW Greater Gabbard Offshore Wind Farm Project. The project features 140 wind turbines, each having a rated capacity of 3.6 MW. The turbines are mounted on a steel monopile and transition piece in water depths between 24 and 34 meters. Three 132-kilovolt (kV) subsea cables bring the power ashore to the new substation. This project produced the first offshore wind farm to be built outside the United Kingdom's territorial waters.

We began onshore construction in 2008, starting offshore construction in summer 2009 and completing the project in 2011.

The project required 84,000 tons of monopiles (steel tubes), which average about 62 meters in length and 600 tons in weight. The monopiles were driven about 30 meters into the seabed. Connecting the monopiles and the turbine towers are 35,500 tons of transition pieces, each weighing about 230 tons and standing as tall as a four-story building.

Conclusion

This project demonstrated Fluor's capability to work closely and in partnership with clients in developing projects from concept to realization. The project was the first of the UK's two Round Two offshore wind farm facilities to move into the construction phase. We applied our major infrastructure and offshore expertise and resources to help Greater Gabbard Offshore Winds Ltd make a meaningful contribution to the UK Government's renewable targets.

This project was consistent with our strategy of applying engineering and technical expertise to enable clients to reduce carbon emissions and increase the supply of green energy.