Red Eléctrica has completed the 66 kV submarine link spanning 36 kilometres, enabling both islands to operate as a single energy system. The investment amounts to €177.5 million and is funded by NextGenerationEU.
Since last July, Tenerife and La Gomera have shared the same electrical system thanks to the commissioning of the submarine interconnection promoted by Red Eléctrica. This infrastructure, which connects the substations of Chío, in Guía de Isora, and El Palmar, in San Sebastián de La Gomera, represents a qualitative leap in the energy management of the archipelago.
The cable, with a double circuit and 66 kilovolts, runs nearly 36 kilometres, mostly underwater, allowing energy to flow in both directions. In this way, both islands can support each other in the event of any incidents, optimising supply security and reducing dependence on fossil fuels.
The total investment for the project has been €177.5 million, partly financed through the Recovery, Transformation and Resilience Plan with European NextGenerationEU funds. The project also includes the construction of two new 66 kV substations, one on each island, specifically designed to manage this new energy highway.
For La Gomera, which previously operated as an isolated system, the interconnection represents a paradigm shift. The island can now integrate a greater amount of renewable generation and even export surpluses to Tenerife, sometimes exceeding its own electricity demand. This promotes a more efficient use of energy and contributes to the decarbonisation of the archipelago.
In Tenerife, the new Chío substation strengthens the transport network on the western slope, an area with increasing energy demand. The quality and reliability of the supply improve significantly, especially for the municipalities in the south and west of the island.
The project has posed a major technological challenge. The underwater section reaches a maximum depth of 1,145 metres, making it the deepest 66 kV three-pole alternating current submarine link in the world. To withstand the extreme conditions of the seabed, a specific cable has been designed using lightweight and highly resistant materials.
The geological uniqueness of the channel between the two islands, with volcanic bottoms and high environmental value, has influenced the execution of the work. Red Eléctrica has employed horizontal directional drilling to introduce the cable into the sea through a micro-tunnel whose exit is located several hundred metres from the coast. This method virtually eliminates any impact on the biodiversity of the shallow waters and minimises the alteration of the coastline.
The substations of Chío and El Palmar incorporate GIS (Gas Insulated Switchgear) technology, which allows electrical equipment to be housed inside compact buildings, reducing their visual and environmental footprint. Both facilities have been designed with landscape integration and sustainability criteria.
With this interconnection, the Canary Islands consolidate an energy cooperation model between islands that was already functioning between Lanzarote and Fuerteventura. The electrical network of the archipelago gains resilience, efficiency, and capacity to accommodate renewable sources, aligning with the objectives of the energy transition.
The residents of La Gomera and Tenerife will notice greater stability in the supply, especially in situations of high demand or outages. Additionally, the reduction in the use of fossil fuels will have a positive impact on air quality and the fight against climate change.
The interconnection is set to be a key piece for the Canary Islands to achieve their decarbonisation goals, allowing clean energy generated on one island to benefit the other. The next step, according to industry sources, could be the connection of La Palma with Tenerife, although there are currently no specific dates.
