The case for the new cable
In 2012, two cables, EDF1 and Normandie 2 (N2), delivered power to the Channel Islands from France.
Our third subsea cable project was already in the latter stages of development, but when EDF1 failed permanently after 28 years of service, the need for the third cable became urgent.
A new route to secure supply
Designed from the outset with security paramount, we installed Normandie 3 (N3) along a more southerly route than our previous cables.
The N3 circuit would comprise of a 19km land cable that took power from the French grid at Périers to Armanville Beach in Normandy, a 32km subsea cable to Grouville Bay, Jersey, and a final 7km land cable to transfer power from the subsea cable to our South Hill Switching Station in St Helier.
When completed in September 2014, N3 would double our import capacity.
We first discussed the idea of a third interconnector to France and considered two possible routes.
Initial costings and feasibility talks with RTE, the French distribution company.
Jersey Electricity Board formally initiates the project.
Desktop feasibility study complete. Discussions with RTE who preferred the northern route. We preferred a southern route as it provided the least risk and most significant strategic benefit.
Breakthrough for us as the announcement of a third nuclear reactor to be built at Flamanville shows a 400kV substation to be built near Périers. This reinforces southern route credentials of a sandy seabed with a sound connection point. Start of marine geophysical and benthic studies.
Agreement on the route from French Fishermen’s Committee Local des Pêches and Jersey Fishermen’s Association.
IFREMER and CERESA commissioned to produce marine and landside enquiry documents
Consultations with French authorities Jersey Environmental Impact Assessment carried out.
Technical and Financial Proposition received from RTE.
French authorities formally declare project ‘live’ and forecast a consultation process of four years.
We investigated the simultaneous installation of Normandie 4, but this would have jeopardised the N3 schedule.
Planning Application due before Préfet de la Manche.
Expected Public Enquiry delayed due to French administration changes and IFREMER diverted by French Oyster crisis.
Planning Application submitted.
Public Enquiry starts.
Favourable outcome announced.
Final Planning Permission confirmed. Tenders considered and accepted.
Contracts worth £45m for manufacture and installation of 35km, (3km spare) submarine cable and 7km Jersey landside cable, related network components and specialist civil works, signed with Italian cable systems specialists Prysmian Powerlink. RTE later also award French land cable to Prysmian.
7km Jersey groundworks start between Gorey and South Hill.
Agreement signed with Guernsey Electricity to share cost and capacity of N3.
French groundworks preparing route from Armanville to Périers get underway.
Manufacture and testing of subsea cable completed at Prysmian’s Arco Felice plant, Naples.
Manufacture of Jersey land cable completed in Gron, France, and cable delivered to Jersey.
Cable Enterprise starts the journey from last assignment in Vietnam to France via Naples to collect N3 subsea cable.
ABB start manufacture of South Hill and Périers regulators in Vaasa, Finland.
Geophysical and Unexploded Ordnance (UXO) surveys start from Jersey:
Cable Enterprise arrives Naples to collect submarine cable.
First of five Jersey land cable joint excavations start.
Jersey land cable starts to be pulled through ducts and jointed.
Pre-laying of grapple hooks on Pirou Plage, Armanville, in preparation for Cable Enterprise arrival.
Prefet issues an “Arête” prohibiting fishing in the working zone.
Cable Enterprise arrives in Brest for two weeks of testing and mobilisation preparation.
Meeting with Professional Fishermen reference claims for loss of fishing gear.
19: Cable installation starts on the beach at Armanville.
22: Cable Enterprise starts 32km journey to Jersey assisted by three anchor-handling tugs, The Zwerver III, The Norne and the Afon Lliffo
1: Improved tides enable installation to become 24/7 operation and progress is around 1.2km a day.
25: Cable Enterprise enters Jersey Territorial Waters. Sub-contractors GPC Ltd install Horizontal Directional Drilled (HDD) duct at Long Beach
29: Jersey Electricity Chief Executive Chris Ambler, Guernsey Electricity MD Alan Bates and Prysmian Powerlink General Manager Renato Grampa, accompanied by media party visit the Cable Enterprise during operations.
11: Unexploded Ordnance Survey(UXO) team give final clearance for Cable Enterprise to begin the approach to Long Beach.
13: Enterprise starts grounding out at low tide 1km off the Gorey shoreline.
14-15: Gradually progresses up the beach with the aid Spring tides as GPC team prepare and rig beach for cable landing.
15: With a tidal window of four hours, the crew successfully offload the cable in 120 minutes. The on-board team cut and seal cable ends.
16: Final cable handoff. Beach anchors released and recovered, tow wires secured, Enterprise eases away from the beach to safe water.
17: With all equipment sea-fastened, Enterprise leaves Jersey Waters for Rotterdam with 3km of spare cable to be stored at Dordrecht.
GPC beach team pull the cable to within 50 metres of the duct under the dune.
18: Cable winched through the ducting into the transition bay in Long Beach car park.
21-22: GPC team bury cable on the beach.
28: Final section of cable at low water mark buried when Spring tides make it accessible.
30 Horizontal Directional Drilling under dune at Armanville for French end of the cable to be pulled to their joint bay.
22: Final section of Jersey land cable pulled through from South Hill to Havre des Pas.
26: French land cable jointed to subsea cable.
7-21: Jointing Jersey land cable to subsea cable.
23: Normandie 3 circuit first switched on and energised to 90kV and ‘soaked’ for 24 hours.
24: Normandie 3 circuit breaker closed to bring power into Jersey from the new circuit for the first time.
14: Normandie 2 circuit switched out for modifications and refurbishments to the protection and control systems.
16: RTE grant permission to operate N2 and N3 in parallel up to 160MW. La Collette generation stood down. Generators in Guernsey closed down every night.
Normandie 3 project diary
From the first discussions to switch-on, the Normandie 3 project took the best part of 11 years. Click more to read our in-depth project diary.
We carefully balanced power between the N2 and N3 submarine cable circuits at just under 45MW each for the ensuing three weeks while engineers closely monitored the new circuit. We switched out N2 on 14 October for extensive modification works and refurbishments to the protection and control systems both here and in France. This provided the opportunity to run N3 at near full capacity.
Once RTE granted permission for this, John Duquemin, supported by Operations Manager Ian Crawley, closed the two circuits together at 9.26pm on 20 October. Since then, the ‘new-look’ Channel Island Electricity Grid (CIEG) network has been stable and operating well.
The first switch-on and the new-look network
N3 was first ‘switched on’ at 11.40am on 23 September, 2014. It was left energised for 24 hours. At 1.17pm the following day, Patrick Cooney, a trainee shift operator at La Collette, under the supervision of Chief Engineer and Project Manager John Duquemin, closed the N3 circuit breaker at South Hill Switching Station to bring power into Jersey from the new circuit for the first time.
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