The work being carried out to lay the power line cables for the new electrical interconnection between France and Spain has reached the tunnel that crosses the Pyrenees through the Albera massif. Around 9.00 am on 31st July, 28 specialised workers guided the threading of the cable through the pipes in the trenches at the entrance of the 8.5 km tunnel. 34 km of cable will be required for the tunnel. The cable was deployed at a speed of 12 metres per minute. At the end of the day, 150 metres of cable had been released. The cable laying is the penultimate stage of a gigantic project, which will double the electrical interconnection capacity between France and Spain.
The interconnection is scheduled to be completed by the end of 2014. Work on the project started three years ago and has been carried out by Inelfe, a joint venture between Réseau de Transport d´Électricité (RTE) and Red Eléctrica de España (REE), the companies responsible for electricity transmission in France and Spain, respectively.
The power line comprises two parallel links, and each of these consists of two cables. As in other aspects of the interconnection project, the choice of cables has also been unique. The insulation covering the cables is not paper soaked in oil, as is usually the case with submarine cables, for example. Instead it is dry insulation made from cross-linked polyethylene (better known by its acronym, XLPE), a material that is better suited to the technical characteristics of the power line. It is the first time that this material has been used at this power level (1,000 MW in each of the links) and at this direct current voltage (±320 kV).
The 260 kilometres of cable for the interconnection are transported, by road, on large reels weighing between 42 and 83 tonnes. Trailers with 9 axles and 72 wheels are required for this transportation. 144 joints will be made to connect the various sections of cable along the route, in a laborious and delicate process that requires a highly specialised workforce.