Electricity transmission grid facilities

In 2021, 16 new substation bays were commissioned to increase the overall renewable power capacity. Noteworthy are those in the Almaraz, Brovales and Carmonita substations, with a capacity that ranges between 0.7 and 1 GW.

Among the projects carried out in 2021 in the transmission grid, the following are noteworthy and are listed according to the geographical area in which the work was carried out:

Andalusia: The Gabias-Orgiva, the Arroyovalle-Montecillo Bajo and the Cártama-Los Montes 220 kV lines had their power transmission capacity increased to provide greater security of supply in the area and provide support for the distribution network. The enlargement works for the 220 kV Torrearenillas line were carried out and the 220 kV El Zumajo (Nueva Parralejo) substation was commissioned to contribute to the resolution of technical constraints, provide support for the distribution network, evacuate renewable energy generation, and improve security of supply.

Aragón: Progress continued on the bolstering of the transmission grid around the metropolitan area of Zaragoza with the commissioning of the 200 kV Los Leones-Villanueva double circuit line. In addition, the new 400 kV Cariñena substation and its incoming/outgoing feeder lines for the 400 kV Almazán-Fuendetodos line will enable the Zaragoza-Teruel high-speed railway axis to be powered. On the other hand, progress was made in strengthening the transmission grid in different areas with the commissioning of the 220 kV Mezquita-Valdeconejos and the 220 kV Valdeconejos-Escucha lines, and the 220 kV T Foradada-Escalona, the 220 kV Escalona-T Escalona and the 400 kV Aragón-Mequinenza lines had their power transmission capacity increased.

The Balearic Islands: Noteworthy was the enlargement of the 132 kV Bossa substation to improve the security of supply in the area and of the 66 kV San Martin and the 132 kV Ciudadela substations, which will enable the evacuation of renewable energy generation.

The Canary Islands: The new 220/66 kV El Rosario (Nueva Geneto) substation was commissioned, which together with the two 250 MVA combined capacity transformers, will improve the security of supply in the northern area of Tenerife. In Fuerteventura, the integration of renewable generation has been improved with the enlargement of the 66 kV Puerto del Rosario substation. Finally, on the island of Gran Canaria, the 66 kV Barranco de Tirajana dual node has been enlarged, which will improve the security of supply in the area.

Castilla La Mancha: To promote the evacuation of renewable energy, the 220 kV Torrijos, the 220 kV Villares de Saz and the 400 kV Olmedilla substations were commissioned, continuing with the ambitious plan for the integration of this type of energy in the area. Similarly, and to facilitate the transit of energy flows through the area, works were completed to increase the power transmission capacity of the 220 kV Villares del Saz-Olmedilla1 line.

Castilla y León: Construction work continued on the 400 kV Tordesillas-Galapagar-San Sebastián de los Reyes (SUMA) axis for the meshing between Castilla y León and Madrid, in the section between Segovia and the Community of Madrid. Similarly, in order to increase the security of supply, the 220 kV T Renedo was dismantled and the new 220 kV Renedo-Mudarrita line was commissioned. Lastly, the enlargement of the 220 kV Zamora substation was completed to promote the generation of renewable energy.

Catalonia: The 220 kV Begues and Puigpelat substations were enlarged to facilitate support for the distribution networks, industrial consumers and to contribute to the resolution of technical constraints. On the other hand, progress was made in the development of the 220 kV grid by commissioning the enlargement of the Hospitalet substation that will connect up to the future Cerdá substation.

Extremadura: Special mention should be made of the new 600 MVA transformer in the 400 kV Almaraz CN substation, which will increase support to the distribution network and contribute to the resolution of technical constraints in the area. The 220 kV Jose María Oriol substation received a new reactor, which will improve voltage control in the area. Similarly, the new 220 kV Arenales substation with its connection to the 220 kV Jose María Oriol substation was commissioned and work continued to connect this substation with the 220 kV Cáceres and the 220 kV Trujillo substations. Lastly, the 66 kV Riocaya-Alcaçova interconnection line has replaced the previous 66 kV Badajoz-Alcaçova line, and the new 400 kV Carmonita substation was completed, along with the incoming/outgoing feeder lines for the 400 kV Almaraz CN-San Serván line, which will facilitate the supply of the Toledo-Cáceres-Badajoz railway axis and improve the evacuation of renewable energy.

For the connection of railway axes, new substation bays were commissioned at the Carmonita substation (Plasencia-Badajoz axis), Tomeza substation (La Coruña-Vigo line), Montesa substation (Játiva-La Encina line) and Cariñena substation (Zaragoza- Zaragoza line).

Levante: The commissioning of the new 400 kV Montesa substation and its incoming/outgoing feeder lines for the 400 kV Benejama-Catadau line has enabled the powering of the Albacete-Alicante-Valencia railway axis. In the Murcia region, the enlargement of the 400 kV Carril substation will promote the integration of new renewable generation.

The central area: Progress was made on the actions proposed in the 2015-2020 Planning regarding permitting processes and works.

The northern area: In the Basque Country, the construction of the 400 kV Güeñes-Ichaso double circuit line continued, noteworthy being the commissioning of the enlargement of the 400 kV Ichaso substation. This action is part of the axis that will connect the west of the Basque Country (Abanto-Güeñes axis) with the 400 kV grid in Navarra (Muruarte-Castejón axis) and will increase the evacuation of renewable generation and ensure the committed values of exchange capacity between Spain and France are met. In Cantabria, construction continued on the 220 kV line between Astillero and Cacicedo, which will significantly strengthen the security of supply in the entire city and the port area of Santander. Works were completed for the increase in the power transmission capacity of the 220 kV Garoña-Puentelarrá and the 220 kV Cillamayor-Mataporquera lines, which will allow greater integration of renewable energy and will mean an improvement in the resolution of technical constraints in the area. In Galicia, the new 220 kV Tomeza substation was commissioned in order to help power the high-speed train, with connections to the 220 kV Lourizán-Pazos and the 220 kV Lourizán-Tibo lines. Lastly, to increase the connection of renewable generation, the new 220 kV Lousame-Mazaricos line was commissioned.

Spain’s National Energy and Climate Plan (NECP) proposes increasing the exchange capacity with Portugal up to 3,000 MW and up to 8,000 MW with France, by means of three new electricity interconnections.

Cross-border connections continue to be key elements in the energy transition in order to achieve greater integration of renewable energy and to advance along the road to decarbonisation. The strengthening of interconnections will continue to be a priority in the development of the transmission grid in the coming years.

The last interconnection commissioned between Spain and France (Baixas-Santa Llogaia) at the end of 2014 doubled the electricity exchange capacity between Spain and France (from 1,400 MW to 2,800 MW), which has contributed to strengthening the security of the two electricity systems and to boosting the integration of a greater volume of renewable energy. However, despite this increase, the degree of interconnection of Spain still continues to be far below the targets set by the European Union of 10 % and 15 %, for 2020 and 2030, respectively.

Spain’s National Energy and Climate Plan (NECP) makes this clear and proposes increasing the exchange capacity with Portugal up to 3,000 MW and up to 8,000 MW with France, by means of three new electricity interconnections. The interconnection between Gatika (Spain) and Cubnezais (France) will basically be the first underwater interconnection between Spain and France (‘Bay of Biscay’ project), and there are two other projects via the Pyrenees¹.