Working within a sensitive, flood vulnerable environment – Landing the power cable for the Race Bank Offshore Wind Farm

The UK wind Industry is 25 years old and now generates sufficient electricity to meet the needs of close to ten million British homes. The first wind farm was switched on in 1991 and consisted of 10 turbines, powering 2,700 homes a year. Today there are more than 1,000 commercial-scale UK wind energy projects, with 27 located offshore. For every offshore wind farm an export cable is buried in the seabed from deep water, across the seabed to the foreshore and onto land. The selection of the landfall site defines the boundary of the marine works and the availability of suitable sites is often limited owing to several factors.

One of the largest offshore wind projects in construction today is the DONG Energy Race Bank Offshore Wind Farm (ROW) project, located 27km north of the coast of Norfolk, on the East coast of England. The ROW cable route crosses one of the most sensitive and heavily studied environments in the UK, the Wash, and through a ca. 50-year-old sea defence embankment (SDE). This sea defence was close to being overtopped in December 2013 when many parts of the East coast of England were impacted by a large North Sea storm surge event. Because of the flood risk and environmental designations, interest in the project was high; Government Statutory bodies such as Natural England (NE), public bodies such as the Environment Agency (EA) and Marine Management Organisation (MMO), as well as local planning authorities (LPA) and well-informed stakeholder groups.

This paper focuses on two phases of the landfall element of the ROW project; (1) the design and consenting process and (2) the construction phase. Through early stakeholder engagement, in parallel with the design process, the construction methods and sequences were agreed to minimise the environmental impact and to ensure flood risk mitigation measures were in place. Planning Permission and an Environmental Permit were granted in early 2016 and two export cables were successfully installed across the sensitive site and through the sea defence in a single summer season, working around periods of overwintering birds and high tides.

One key conclusion from the ROW project is that ‘Early’ engagement cannot be early enough. Early consultation led to a better understanding of stakeholder’s short and long term objectives, unearthing site-specific unknowns and confirming or dismissing assumptions early in the design process.

If UK offshore wind is to continue the momentum gained over the last 25 years and to fulfil the vision to be one of the leading world markets, developers must continue to commit to delivering appropriate care of the environment and deliver a collaborate engagement culture with stakeholders and local communities. Where this is most challenging is at the interface between land and sea, the Landfall.