Metoc plc has completed marine cable engineering and consent applications for the construction of BritNed’s 600 million Euro HVDC interconnector. When it becomes operational at the end of 2010, the Interconnector will enable energy trading and increase the security of supply between the UK, The Netherlands and the wider European market.
BritNed is a joint venture between the two power companies National Grid in the UK and TenneT Holding B.V. in The Netherlands to develop the 1000 Megawatt HVDC system. The Interconnector will comprise a 260 km long cable that will be buried into the seabed across the southern North Sea. Converter stations at the Isle of Grain in Kent and on the Maasvlakte area of the Port of Rotterdam will connect the BritNed cables into the UK and Netherlands grids.
Since the start of the project in 2001, Metoc has managed a broad programme of works to address the environmental design and risk management issues in the routing, installation and consenting processes needed for the interconnector development.
Ian McLelland, BritNed Joint Technical Director, says “Metoc has been an integral part of the team on this project and provided specialist onshore and offshore consultancy, engineering and project management, supported the environmental consents/licences process and successfully undertaken crucial parts of the tender assessments to enable the project to progress to the construction phase.”
Comprehensive land and marine surveys were specified, managed and supervised by Metoc to: select the cable route; support the permitting requirements in the two countries; and inform tenderers for the construction contract. Based on the survey data and specialist studies of discrete subjects, such as sediment dynamics, Metoc developed and assessed multiple alternate cable route options and analysed installation techniques and timings to ensure environmental compliance.
Work also included an investigation of the preferred cable route and a full risk assessment and specification of protection burial depths for the cable system. Based on the survey data, the sediment dynamics were mathematically modelled to investigate the potential environmental impacts of dredging along the cable route, in particular across the large-scale sand waves in the Dutch sector.
Metoc produced the EIR (Environmental Impact Report) for the preferred cable route through UK waters and obtained consents under Coast Protection (CPA) and Food and Environmental Protection (FEPA) legislation, as well as approvals from the Port of London and Medway Ports Authorities. In the Netherlands Metoc worked with local subcontractors, Royal Haskoning and Svasek, to compile the full scale Environmental Impact Assessment needed to support permit applications for the Dutch sector of the route.
At the core of the project is a GIS (Geographic Information System) developed by Metoc to store and collate the vast amount of data needed to support the project.
The Company played an integral role in putting together the technical aspects of the Invitation to Tender (ITT) documentation and the review of tender returns that resulted in the award of the cable supply contract to ABB who have subcontracted the installation to Oceanteam.