Interconnections are seen as key to developing an internal energy market and the proposed Energy Union in Europe. [Engerati-European Energy Union Proposed To Transform Energy System]
Among these the latest to come online is the 64.5km powerline connecting the towns of Baixàs, in the Rosellón region of France, and Santa Llogaia, in Alto Ampurdán in Spain. This powerline, named a ‘project of common interest’ (PCI), doubles the existing electricity interconnection capacity between the two countries from 1,400MW to 2,800MW, and helps connecting the power system of the Iberian Peninsula to other European energy markets.
The total cost of the project was €700 million, of which €255 was covered by the EU under the European Energy Programme for Recovery. Approximately 33.5km runs in France and 31km in Spain, with the line trenched on both sides and crossing the Pyrenees at the Albera massif through an 8.5km tunnel.
“After so many years, the completion of this truly landmark project shows our renewed determination to achieve a fully integrated energy market in Europe,” commented Miguel Arias Cañete, the European Commissioner for Climate Action and Energy, at the inauguration. “The increased interconnection capacity will allow renewable electricity to flow more freely in the European market, and make the European power system more reliable. More energy companies will also be able to compete across borders, resulting in greater choice and cheaper energy prices for consumers.”
Innovative converter technology
The 320kV powerline, which is expected to come into full commercial operation in June, is a project between the French and Spanish TSOs, Réseau de Transport d’Électricité (RTE) and Red Eléctrica de España (REE), through the jointly owned corporation INELFE (France-Spain ELectrical INterconnection).
The project encompasses several technological milestones: It is the first time that an underground interconnection of this length and a power capacity of 2,000MW has been carried out. A new type of cable for DC transmission of voltage levels of 320kV was developed. Further, a new type of voltage source converter (VSC) technology, the modular multilevel converter (MMC), has been incorporated in the converter stations, which have been built at each end of the line, with the capability to reverse the direction of flow of the energy exchanges between the two countries in just 50ms.
More than 500 companies have been involved in the project, most notably Prysmian, which was responsible for manufacturing the cable, and Siemens, which built the two converter stations.
The project was also supported by the European Investment Bank (EIB) with a €350 million loan to RTE and REE.
France-Spain projects of common interest
A second PCI interconnection between the two countries is a 320kV or 500kV line between Aquitaine in France and the Basque country in Spain, which is currently undergoing a feasibility study. The 360km line with a capacity of 2,000MW would include an HVDC subsea cable interconnection via the Biscay Gulf. Commissioning would be in 2020 or later.
The project would be intended to increase the cross-border capacity between France and Spain, as well as help renewables integration (mainly wind) in the Iberian Peninsula by making possible exports towards mainland Europe. However, a key challenge is crossing the deep Cap Breton canyon with a submarine project.
The third electricity PCI between the two countries is the proposed installation by REE of a new phase shift transformer (PST) in the Arkale 220kV substation, with the aim to increase the capacity of the existing interconnection between Arkale and Argia in France. The design stage is currently underway, with a 2017 commissioning in prospect.
10% interconnection by 2020
Under the proposed Energy Union plans, European member states will be required to achieve an interconnection of at least 10% of their installed capacity by 2020.
To date, the electricity interconnection capacity between France and Spain only covered 3% of peak demand in the Iberian Peninsula. This very low level of interconnection capacity is seen as a major obstacle for the creation of a regional electricity market in southwest Europe and as having prevented the energy companies of the Iberian Peninsula from participating in the EU internal electricity market.