A new high-voltage electricity power line which will run three metres away from Eurostar and GetLink trains in the Channel Tunnel is set to be operational this summer.
It will be the third line to link Europe with the UK.
Rated at 1GW, the line should be able to supply the simultaneous electricity needs of around 750,000 households.
The first two lines were buried in the sea bed, one rated at 2GW in 1986, and the other rated at 1GW early last year.
The new line, owned by GetLink, (formerly Groupe Eurotunnel), cost €665million and was built and will be operated by ElecLink, a firm it wholly owns.
UK uses excess French nuclear power
Since the introduction of the power interconnections, most of the flow has been from France to the UK, especially at night when France’s nuclear power stations produce a large surplus.
Nuclear power stations are designed to generate a fixed amount of electricity when they are in operation and cannot easily be turned down when demand is low, like gas or oil-fuelled stations.
ElecLink said it will enable both countries to use more electricity from solar and wind generators by improving the ability to supply when there is no sun and little wind, and to sell surpluses on windy, sunny days.
The 51km-line will link the UK’s National Grid Sellindge substation in Kent to a substation in Les Mandarines, Pas de Calais.
New link for Ireland
Ireland is also seeking an electricity link with France, fearing that its reliance on existing links with the UK will be increasingly at risk from Brexit. Plans have been announced for a 700MW link, costing €1billion, with work starting this year on the 575km of cable needed, and due to be completed in 2026.
Half of the money for the link, which will run from Cork to Brittany, will come from the EU, with the rest from Ireland.
Crossborder electricity connections have flourished in recent decades in France, which now has 51 connections with its neighbours.