The connected future

At Guernsey Electricity, we maintain the ability to generate enough energy to power Guernsey, but we aim to import the majority of our electricity from sustainable sources in France.

Guernsey Electricity has been operating GJ1 for over 18 years.

When it was energised, it transformed the islands electricity supply, and since that time it has imported over 4,500 GWh (Giga Watt Hours.) This is enough energy to boil 45 Billion kettles full of water - give or take a few!

Our current subsea cable which forms part of the CIEG network connecting Guernsey to Jersey (and onwards to France) known as GJ1, suffered a number of faults in late 2018 and early 2019. Therefore, we are investing over £30m in a replacement subsea cable in order to return Guernsey to a position of being able to import lower-carbon electricity from France.

The replacement cable is being manufactured and is intended to be in service by the end of this year.

Once energized, a third of our electricity will come from tidal power at La Rancel barrage in St Malo.

GJ1 timelines

Why replace GJ1?

GJ1 has key strategic importance. It provides an interconnection between Guernsey and France, via Jersey contributing to each jurisdiction's objectives, enhancing energy security and enabling the further integration of renewable, low carbon energy sources.

We know that this will deliver many benefits:

Every unit of electricity imported replaces a unit generated from fossil fuels. Therefore reducing emissions of greenhouse gases as well as the islands reliance on international supplies of fossil fuels (coal gas and oil.)

Where will the cable go?

This replacement cable will be following the same route as the current cable and will also come ashore at Greve de Lecq and Havelet. The cable route has been selected to take advantage of favourable sediments for cable burial and to minimise impact and where possible we have reduced the installation corridor in order to ensure minimum impact to marine users.

Onshore works are needed as part of this project, including trench works on and off the beach. In order to complete this work safely traffic management measures will be put in place, the details of which will be issued as required.

We understand that these works may cause inconvenience, and we will endeavour to minimise this where we can.

Your safety in mind

Constructing and commissioning an interconnector requires the completion of a thorough programme of environmental and technical assessments to ensure that the final design fully considers the environment in which it is built.

Guernsey Electricity is committed to carrying out all construction and operation activities in a way that minimises the risk to safety, health and the environment.

GJ1 cable interconnector image

How will it affect the local environment?

As part of the environmental impact assessment process, we will work closely with all stakeholders, business owners, residents and tourism, including you, to understand and address any concerns and keep everyone informed before and during the project.

A detailed understanding of the environmental and social sensitivities, both onshore and offshore, will be an important focus and willbe achieved through site-specific surveys.


This project will involve the construction and commissioning of different onshore elements, including cable trenching and works at the substations.

Activities will only last for a few months, but we understand that this may cause inconvenience and we apologise for this and will do everything we can to work with you to ensure that any impacts are minimised as much as possible.

If you have any questions or concerns please call us on 01481 200700 or email