Geologists are set to carry out a survey of proposed cable routes for a planned extension to the Greater Gabbard Offshore Wind Farm, which lies off the East Anglian coast.

Three wind farm survey vessels will spend the next three months examining the cabling routes for North Falls Offshore Wind Farm in the Southern North Sea.

The vessels will operate out of Harwich Port and it is expected the surveys will be completed by the late summer. Greater Gabbard is operated and maintained by a 100-strong team operating out of Lowestoft.

The proposed North Falls site — owned by SSE Renewables and RWE Renewables which have created a 50/50 joint venture company — lies 20km off the coast of Suffolk and covers around 150km sq.

The comprehensive surveys will be carried out by marine survey contractor Fugro. They will be part of the project’s environmental impact assessment and the data collected by the survey is aimed at helping the team to understand the local marine environment.

The 42m Fugro Mercator and 12m Fugro Seeker will conduct geophysical surveys of the seabed. The 27m Curtis Marshall will take a portion of the sea floor — or benthos — to examine the organisms that exist there through a process known as a “benthic grab” and will carry out drop-down camera photography of the seabed.

North Falls project manager Martin Whyte said the surveys would enable the project team to assess local environmental conditions and identify and locate protected marine species and habitats. The data collected will form a baseline understanding of the area.

“From the environmental data and samples gathered we will be able to identify risks and impacts and develop plans for mitigation, while the survey results will also feed into the early design and engineering of the project’s offshore infrastructure,” he said.

“The information will also help to determine what type of further detailed survey works are likely to be required as the project progresses.”

SSE Renewables and RWE Renewables signed an Agreement for Lease with the Crown Estate, which manages the UK seabed, in September 2020 to extend the existing 504 megawatt wind farm by a further 504 megawatts. Its final capacity will be decided during the development and consent process. The final capacity of the project will be determined during the development and consenting process, the wind farm developers say.

The project is named after the North Falls sandbank at the southern tip of the proposed site of the wind farm.

Over the next three years engineering design, stakeholder consultation and community engagement work will take place. A Development Consent Order bid is expected to be submitted to the Planning Inspectorate in 2023.

The Greater Gabbard Offshore Wind Farm is also a 50:50 joint venture between SSE Renewables and RWE Renewables. It contains 140 wind turbines and has been in operation since 2012, powering the equivalent of 400,000 homes.