Western Link: the project laying the world's longest underwater power line

This project, which will require an investment of €1,200 million, will enable the transmission of renewable energy from Scotland to homes and businesses located in Wales and England by laying 850 km of high-voltage cable, 770 of which will run under the sea.

Iberdrola, through its subsidiary ScottishPower, and National Grid, the British grid operator, are building the undersea interconnection system between Scotland, England and Wales by laying a high-voltage cable: Western Link. The cable has an 850 kilometre length — out of which 770 km are undersea — and it connects the west coast of Scotland with Quay Bay, on the north coast of Wales. This is achieved through a two-directional system: the flow of electricity moves towards the north or south, according to the supply needs and demand for electricity.

The project will require an investment of €1,200 million and make it possible to transmit renewable energy generated in Scotland to homes and businesses in Wales and England, while increasing the interconnection capacity by over 2,200 megawatts (MW), enough to supply the electrical demand of more than four million homes every year.

Recently, Ignacio Galán, Chairman of Iberdrola, visited the Hunterston station to check the huge progress the team is currently making at this crucial moment: the initial energisation of the project.

The entire project can be divided into five phases:

  • Construction of a converter station in Hunterston, North Ayrshire, to change from the current DC system to an AC system, so it can be used with the current electricity transmission system.
  • Laying approximately 4 km of high-voltage DC cable to the point in which the undersea cable reaches land, in Ardneil Bay.
  • Laying an undersea cable with a length of approximately 385 km between Ardneil Bay and Leasowe, in the Wirral Peninsula.
  • Laying a high-voltage underground cable with a length of approximately 33 km, which will run through the Wirral Peninsula.
  • Construction of a converter station in Deeside, Flintshire.

Western Link was established as a result of the new energy paradigm in the United Kingdom, in which the generation of renewable energies has increased to cater for the growing demand of the country.

Ship used for submarine cable laying operations.Ship used for submarine cable laying operations.