In July, Red Eléctrica, the Redeia subsidiary responsible for electricity transmission and operation of the Spanish electricity system, will begin transporting a series of large-scale pieces of equipment from the Port of Bilbao to the converter station currently under construction in Gatika (Bizkaia). In total, this involves seven high-voltage electrical transformers for the electricity interconnection with France through the Bay of Biscay. 

HITACHI Energy, Red Eléctrica’s contractor, will transport the electrical transformers by ship to the right bank of the Bilbao estuary. From where they will be moved by road to the Gatika converter substation. 

The size of the equipment requires special transport measures. For this reason, Red Eléctrica and the authorities responsible for these roads are working in close coordination to minimise disruption to traffic by selecting periods with the lowest traffic density.

Each piece of equipment weighs 315 tonnes and measures 10 metres long, 4.7 metres wide and 5 metres high. As a result, each transformer must be transported individually by road from the Port of Bilbao using a special transport vehicle consisting of a multi-axle trailer. 

Equipment for a strategic, sustainable European project

The electricity interconnection will link the electricity systems of the Iberian Peninsula and France through two 400 kV links running from Gatika to the French town of Cubnezais, near Bordeaux. The route will be entirely underground and submarine, minimising its impact on the surrounding environment. 

Due to the considerable length of the interconnection and in order to minimise energy losses during transmission, this infrastructure is being developed using high-voltage direct current (HVDC) technology. Therefore, the converter stations located at both ends play an essential role, as they connect two electricity systems that operate using alternating current. The transformers to be installed at these stations have been specially designed to facilitate the conversion process between direct and alternating current, subsequently allowing a safe and efficient integration of energy into the electricity transmission grid.

The interconnection will increase the electricity exchange capacity from 2,800 to 5,000 megawatts (MW), nearly doubling it, to advance toward the European Union's interconnection targets. The project will improve the quality of electricity supply, increase the efficiency of the Iberian Peninsula and French systems, and facilitate greater integration of renewable energy, in line with national and European climate change targets.

This initiative is included in the current Planning cycle and has been designated a Project of Common Interest by the European Commission, with financial support from CINEA and the European Investment Bank. The project is being developed by Inelfe, a company jointly owned by Red Eléctrica and its French counterpart, RTE.