Electricity transmission grid facilities

During 2023, despite the complexity of the geopolitical context, investment in the transmission grid has increased to 744.6 million euros, 65.9 % higher than the previous year. These investments have contributed to integrating increased renewable energy sources, strengthening inter-island links, improving grid meshing, promoting electrification, guaranteeing security of supply, and ensuring quality of service.

Throughout 2023, 157 kilometres of lines and 143 substation positions were commissioned, bringing the total length of lines in the national transmission grid to 45,223 kilometres, a 0.4 % increase compared to 2022. In addition, transformer capacity increased by 760 MVA, bringing the total national transformer capacity to 94,981 MVA (0.8 % higher than in 2022).

Facilities in the electricity transmission grid in Spain

Km

Annual evolution of the electricity transmission grid in Spain

Annual evolution of the transmission grid by systems

Among the projects carried out in the transmission grid in 2023, the following are the most important, according to their geographical area of development:

Andalusia: new 220 kV substations were commissioned in Atarfe, Andújar, Caparacena, Chucena, Entrenucleos, Gazules, Guadame, Rocío and Santiponce, some of which are intended to increase the integration capacity of renewable generation and others to support the distribution grid. New 400 kV substations were also commissioned in Archidona, Cabra, Guillena, Caparacena Cártama and Guadame, extending the capacity of the system to optimise the use of renewable resources. The new Castellar 400 kV substation is particularly noteworthy, as it supports the electrification needs of the high-speed railway network.

As a continuation of the work on the Caparacena-Baza-La Ribina axis completed in 2022, the extension of the Baza substation has been completed. This, together with the renovation of the Guillena, Santiponce, Pinar del Rey and Guadame 220 kV substations, and the Guillena 400 kV substation, will improve the quality and security of supply in a large area.

Aragon: progress continued in reinforcing the transmission grid across different areas of the Aragon region with the commissioning of the new Platea 400 kV substation and the increase in capacity of the Jalón-Magallón 220 kV line. The Rueda del Jalón and Peñaflor 400 kV, and Esquedas and María 220 kV substations were extended to increase the capacity for connection and evacuation of renewable generation. In addition, a dynamic line rating device (DLR) was installed in order to optimise utilisation of the two circuits on the Fuendetodos-Maria 220 kV line.

Balearic Islands: the 132 kV submarine cable between the islands of Ibiza and Formentera has been commissioned, which will substantially reinforce the quality and security of the electricity supply, enable 100 % demand coverage in Formentera and accelerate the energy transition in the Balearic Islands by reducing CO2 emissions. The Marratxí 66 kV substation has also been renovated and the extension of the San Martín 220 kV substation has been completed.

Canary Islands: on the island of Gran Canaria, the El Tablero-Lomo Maspalomas 132 kV line, the El Sabinal 66 kV substation connection line and the increase in capacity of the El Sabinal-Barranco Seco 66 kV line have been commissioned. All of these will improve the security of supply in the area.

In Tenerife, the Candelaria-Caletillas 220 kV line has been completed. In Fuerteventura, the line between Gran Tarajal and Matas Blancas has been commissioned, as well as the Gran Tarajal 132 kV substation and its connection line to the Los Vallitos 220 kV substation. And lastly, also connecting to the Los Vallitos substation, the Granadilla-Los Vallitos 220 kV line has been commissioned.

Castile and Leon: the evacuation capacity for renewable energy sources has been increased with the commissioning of the extensions to the Luengos, Olmedo, Velilla and Villameca 400 kV substations, and the extension of the Zaratan, Trevago, Medina del Campo, Villalvilla and Las Arroyadas 220 kV substations.

Castile-La Mancha: the Brazatortas 400 kV substation has been commissioned for the evacuation of renewable energy. Similarly, to facilitate the transmission of energy flows, a ballast has been commissioned at the Belinchón 400 kV substation.

Catalonia: the 220 kV grid developments to connect the new Cerdá substation to the meshed grid were commissioned, consisting of the connection lines to the Zona Franca, Airport and Hospitalet 220 kV substations. The extension of the Puigpelat 220 kV substation for the integration of renewable generation has been completed, and various initiatives to improve security of supply in the area were also completed, such as improvements to the La Selva-Tarragona 220 kV line, the increase in capacity of the Constantí-Tarragona 220 kV line and the extension of the Garraf and Rubí 400 kV substation. And lastly, work continues on the construction of the lines between the Mangraners, Espluga and Begues 220 kV substations.

Extremadura: the Almaraz CN 220 kV and 400 kV substations were renovated, along with the Mérida 220 kV substation. The extension of the Almaraz ET 220 kV substation has been completed with a view to increasing the renewable generation integration capacity. The capacity increase of the Aldeadávila-Arañuelo 400 kV line has been completed to increase security of supply. Progress continues also on the permitting and work on the rest of the initiatives set out in the 2021-2026 Plan.

Levante: in the Valencian Community, the Ayora-Cofrentes 400 kV line was commissioned which, together with the El Serrallo 220 kV substation, provides support for the distribution grids and improves the reliability of supply in the area. The extensions to the La Plana, Ayora, Sax and Requena 400 kV substations have also been commissioned to increase the security of the system, as well as the connection and evacuation capacity of renewable generation.

In the Region of Murcia, the El Sequero and Balsicas 220 kV, and Campos and Totana 400 kV substations were commissioned, facilitating greater integration of renewable energy.

Central area: in Madrid, one of the highlights is the new San Fernando 400/220 kV substation, which will increase the reliability of the system and the security of supply, together with the extensions at Loeches 400 kV and the renovations at Villaviciosa, Moraleja and San Sebastián de los Reyes 220 kV. The increase in capacity of the Coslada-Villaverde 220 kV line has also been completed, and progress continued in the permitting and other activities for the remaining initiatives included in the 2021-2026 Plan.

Northern area: in the Basque Country, the first STATCOM of the grid has been commissioned at the Vitoria 220 kV substation. This enables the implementation of such devices on the grid, which will increase the security of supply. The renovation of the Gatica and Itxaso 220 kV substations has also been completed. The latter is related to the 400 kV Güeñes-Itxaso double circuit, where construction continues at a good pace. This investment is part of an axis which will connect the west of the Basque Country (Abanto-Güeñes axis) with the 400 kV grid in Navarre (Muruarte-Castejón axis) via Itxaso, increasing power evacuation capacity and providing greater integration of renewable sources, as well as ensuring the committed exchange capacity values between Spain and France.

In Navarre, the La Serna and Castejón 400 kV and Olite 220 kV substations have been extended to facilitate the integration of renewable energy. Additionally, the extension of the Muruarte 220 kV substation and the capacity increase of the La Serna-Tudela 220 kV line have been completed in order to improve the reliability of supply. And lastly, the extension of the La Serna 220 kV substation was commissioned in order to provide support for the distribution grid.

In Cantabria, the extension of the Cacicedo 220 kV substation was completed to reinforce security of supply for the area of the city and port of Santander. A transformer at the Aguayo 400 kV substation has been refurbished, which will also help to improve the reliability of supply.

In Galicia, the new O Incio 220 kV substation, together with its connection lines to the meshed grid were completed to support the electrification needs of the high-speed railway network. The extensions to the Xove and Silleda 400 kV and the Santiago de Compostela 220 kV substations have also been completed to increase connection capacity, the evacuation of renewable generation and the security of supply. Work is also under way on the Beariz and Fontefria substations, as part of the northern interconnection with Portugal.

Interconnections continue to play a key role in the energy transition to achieve greater integration of renewable energy sources and progress in decarbonisation. The strengthening of international interconnections remains a priority for the coming years in the development of the transmission grid, as highlighted in the 21-26 Plan.

The latest interconnection commissioned between the electricity systems of Spain and France (Baixas-Santa Llogaia) at the end of 2015 doubled the electricity exchange capacity between Spain and France (from 1,400 MW to 2,800 MW), helping to reinforce the security of the two electricity systems and favouring the integration of a greater volume of renewable energy. However, despite this extension, the degree of interconnection in Spain remains below the targets set by the European Union, of 10 % and 15 % for 2020 and 2030 respectively.

The Spanish National Integrated Energy and Climate Plan (PNIEC) made this clear and proposed increasing the exchange capacity with Portugal to 3,000 MW and with France to 8,000 MW, by means of 3 new electricity interconnections. These objectives were confirmed in the latest revision of the PNIEC. The interconnection between Gatika (Spain) y Cubnezais (France) will be the first fundamentally submarine interconnection between Spain and France (“Golfo de Bizkaia” project); and two other projects across the Pyrenees (Navarra – Landes, and Aragón – Marsillon)¹.