Offshore Structures: Electric Cables
(asked on 26th November 2014) - View Source
Question
To ask the Secretary of State for Energy and Climate Change, how much sub-sea off-shore cabling has been laid in which areas in each of the last 30 years.
In the last 30 years, there has been a total of 1340km of sub-sea electricity transmission cables laid in the waters surrounding the UK.
This comprises 702km of licenced sub-sea offshore transmission cables1 that connect offshore wind farms in UK territorial sea and surrounding Renewable Energy Zone (REZ)2 to shore, and 638km of interconnector cables, consisting of links from the UK mainland to France, the Netherlands, Northern Ireland, the Republic of Ireland and the Isle of Man.
Lengths provided are for sub-sea sections of cables only, and do not include onshore components that link to relevant grid connection points.
Table of licenced offshore transmission projects
Licenced offshore wind farm transmission assets | Sub-sea cable length (km) | Year licence granted | Sea |
Robin Rigg East and West | 25.2 | 2011 | Irish Sea |
Sheringham Shoal | 44 | 2013 | North Sea |
Barrow | 26.6 | 2011 | Irish Sea |
Greater Gabbard | 152.5 | 2013 | North Sea |
Gunfleet Sands 1 and 2 | 9.3 | 2011 | North Sea |
Ormonde | 43 | 2012 | Irish Sea |
Wallney 1 | 45.3 | 2011 | Irish Sea |
Wallney 2 | 43.7 | 2012 | Irish Sea |
Lincs | 96 | 2014 | North Sea |
London Array | 216 | 2013 | North Sea |
Total Cable length | 702 |
Table of interconnectors
Interconnector | Sub-sea cable length (km)3 | Laying year(s) | Connection points | Sea |
IFA | 45 | 19864 | GB – Folkestone, Kent FR - Calais | English Channel |
Moyle | 53 | 20015 | N.I - Nr Belfast, Scotland - near Stranraer | Irish Sea |
BritNed | 250 | 2009 to 20106 | GB - Isle of Grain, Netherlands - Maasvlakte | North Sea |
East West | 186 | 2009 to 20127 | GB - Deeside, north Wales, Ireland - Woodland, County Meath | Irish Sea |
Isle of Man | 104 | 20008 | Bispham, Blackpool to Douglas, Isle of Man | Irish Sea |
Total Cable length | 638 |
[1] Source – Ofgem. Offshore transmission is defined as all electric lines of 132 kilovolts or more which are built for the purpose of conveying electricity generated by an offshore generating station. The km length figure does not include ‘inter array’ cables that connect individual wind turbines to the nearby sub-station.
2 The REZ is an area of the sea, beyond the UK’s territorial sea, which may be exploited for energy production. A map of the REZ may be obtained from the UK Hydrographic Office - https://www.ukho.gov.uk/ProductsandServices/Services/Documents/Renewable_Energy_Web%20Page_Jan06_v2.pdf . A map of the ten offshore transmission projects tendered to date, as well as the five projects currently in Ofgem’s competitive tender process, can be found on Ofgem’s website - https://www.ofgem.gov.uk/electricity/transmission-networks/offshore-transmission/offshore-transmission-tenders
3 Length provided refers to the distance between landing points and does not take into account cable configurations of the interconnectors.
4[1] Refers to the year IFA was commissioned. Source: National Grid - http://faculty.london.edu/mottaviani/IFA.pdf
5 Source: Mutual Energy - http://www.mutual-energy.com/The_Moyle_Interconnector/History_and_Development_of_the_Interconnector.php
6 Source: BritNed - http://www.britned.com/BritNed/About%20Us/Construction
8 Source: AWJ Marine - http://www.awjmarine.co.uk/fishery-liaison/isle-of-man-interconnector/