PICTURES: Huge ship lays electricity cable from Jersey to Guernsey
WITH three electric cables linking Jersey with France’s national grid, the Island’s diesel generators at La Collette and gas turbines on Queen’s Road are seldom needed.
However, following a major failure of its sole interconnector to Grève de Lecq, Guernsey is not in such a fortunate position.
Problems first began for the island during the evening rush hour on 1 October 2018 when power went out across the isle. Firefighters were called to dozens of automatically-activated alarms and a number of cars collided as traffic lights went out of action.
Back-up diesel generators were started up while engineers worked to rectify the issue. They eventually found a fault with the cable at Grève de Lecq – where the cable comes ashore in Jersey. Repairs were made and preparations to bring it into service soon began.
However, Guernsey Electricity quickly discovered another fault with the now 19-year-old 37.4km link, called GJ1. This time the problem lay nine kilometres north of Jersey and the cable has never been brought back to full capacity.
The old cable has since been completely severed and the island has been relying on its diesel generators to provide all of its power needs ever since.
Now, the company is replacing the inter-connector at a cost of £30 million in a project which requires the beach and road at Grève de Lecq to be dug up.
Last week, a huge 140-metre purpose-built ship, the Swedish NKT Victoria, arrived from Sweden – where the cable was manufactured – to begin the installation process. The ship’s arrival follows its initial visit a number of weeks ago when it carried out an initial survey of the route.
Sharon Watchorn, Guernsey Electricty’s project manager, said that the project had been years in the making and that the cable had taken 18 months to make.
‘From start to finish, it will probably be a five-day lay – if there is no disruption due to the swell or weather. That is what they want to do,’ she said.
‘It is one of the most sophisticated cable-laying vessels in the world so if there is a ship that can do it, this is the one.
‘Guernsey is solely running on on-island generation at the moment. In order to install and joint the new cable, we had to cut the existing cable at both ends but we are hoping to be able to switch on the new one at the beginning of November.’
She added: ‘It will be a direct replacement. To be able to utilise any additional energy would mean building additional infrastructure so, because of the emergency nature of the work, we went for the same capacity cable.’
As part of the process to commission the cable, Guernsey Electricity’s project team have also had to assure both Jersey and Guernsey’s environmental authorities that the work would not cause any unjustifiable adverse effects to either jurisdiction’s sensitive ecosystems.
And Francis Binney, marine scientist for Jersey’s government’s marine resources unit, said that the work could actually have a positive effect.
‘A lot of the area that the cable is going through is hard-swept by the tide so a lot of it is fairly bare. My understanding is that certain parts of the new cable will be protected by bags of rock armour so it might actually create habitat and might well have a positive environmental impact.’
Guernsey Electricity has also begun the process of commissioning another cable between Guernsey and France but this is not expected to come into operation until around 2025.