Sheringham Shoal

Location and Site Details

The Sheringham Shoal Offshore Wind Farm is situated in the Greater Wash, off the coast of North Norfolk in the UK. It is located between 17 and 23 kilometers from the shore, approximately 5 kilometers north of the offshore sand bank known as Sheringham Shoal. The site is characterized by relatively shallow water depths, ranging between 17 and 22 meters.

Capacity and Turbines

The wind farm has a total capacity of 317 MW, generated by 88 Siemens Wind Power 3.6 MW turbines. Each turbine consists of an 80-meter tower, a nacelle, and three 52-meter long blades. The turbines are mounted on foundations fixed to the seabed, comprising tubular steel monopiles driven 23-37 meters into the seabed and transition pieces mounted on top.

Infrastructure

• Foundations and Turbines: The monopiles range in length from 44 to 61 meters and weigh between 375 to 530 tonnes. The transition pieces are 22 meters long and weigh about 200 tonnes. The turbines are spaced approximately 700 meters apart.
• Substations: The wind farm includes two 900-tonne offshore substations connected by two 132kV marine cables that make landfall at Weybourne. The substations were transported and installed using specialized vessels.
• Cabling: The project features a 21.3-kilometer buried cable system, including 145kV cross-linked polyethylene submarine export cables and infield cables. The cables were installed by companies such as Nexans, Visser and Smit Marine Contracting, and Global Marine Systems.

Construction and Timeline

• Lease and Planning: The lease for the project site was granted by the Crown Estate in 2004 as part of Round 2. Necessary approvals were received by 2008 after four years of planning and development.
• Construction: Onshore installation work began in the third quarter of 2009, and offshore installation started on March 9, 2010. The installation of foundations began in June 2010, and turbine installation work started in mid-2011. The wind farm became fully operational in late summer 2012.

Ownership and Operation

The Sheringham Shoal Offshore Wind Farm is owned by a joint venture between Equinor, Green Investment Group, and Equitix through Scira Offshore Energy. Equinor operates the wind farm. Initially, the project was developed by Scira Offshore, a joint venture between Statoil (now Equinor) and Statkraft.

Energy Production and Impact

The wind farm produces around 1.1 terawatt-hours (TWh) of renewable energy per annum, which is sufficient to power approximately 280,000 British homes. This energy production results in a reduction of around 500,000 tonnes of CO² emissions annually compared to fossil fuels.

Grid Connectivity

The wind farm is connected to the national grid through agreements with UK-based energy companies EDF Energy and National Grid Transco. The electrical power is transmitted via a 132kV cable system to an onshore substation near Salle, Norfolk.

Maintenance and Services

• Maintenance Contracts: Alstom (now part of GE Renewable Energy) began maintaining the onshore and offshore substations in 2011 and signed a three-year service extension in 2015. 3sun Group won a three-year operational services contract for the offshore wind farm effective from January 1, 2013.
• Community Fund: The Sheringham Shoal wind farm operates a community benefit fund, managed by the Norfolk Community Foundation, which has made grant awards totaling £881,642 since its establishment in 2010.

Future Expansion

In September 2022, Equinor applied for permission to build extensions to the Sheringham Shoal and Dudgeon Offshore Wind Farms. If implemented, these extensions will double the existing capacities of the wind farms, providing green electricity to an additional 785,000 UK homes.

Decommissioning

The wind farm is leased for a period of 40 years from the Crown Estate. Repowering of the wind farm is planned after 20 to 25 years, and decommissioning will be carried out towards the end of the lease period in line with governmental norms.