Western Link

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

Operating plants Electrical network United Kingdom Scotland

This project, which had required an investment of €1,200 million, enables 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 run under the sea.

Proyecto Western Link
Operating plant

Western Link submarine power line

Location West of Scotland and Quay Bay
Capacidad interconexión
Interconnection capacity +2200 MW
Investment 1.200 million euros
Puesta en marcha
Comissioning 2018

Iberdrola, through its subsidiary ScottishPower, and National Grid, the British grid operator, had built the undersea interconnection system between Scotland, England and Wales by laying a high-voltage cable: Western Link External link, opens in new window.. 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 had required an investment of €1,200 million and has made 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.

The entire project has gone through 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.
Ship used for submarine cable laying operations.

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.

Iberdrola, a world leader in smart grids

Smart grids are essential for our renewable energy to reach consumers safely and efficiently in any country in the world. At Iberdrola, we operate one of the most important distribution systems in the world and we continue to work on its modernisation, digitalisation and automation. 

For this reason, in our Strategic Plan, we are focusing on smart grids in addition to renewable energies. To sum up, the company plans to invest €21.5bn in grids in the United States, the United Kingdom, Brazil and Spain, which represents 60% of net investment.