Completion of Submarine Cable Laying Connecting Tenerife and La Gomera

Red Eléctrica has successfully completed the laying of the two submarine cables for the electrical interconnection between Tenerife and La Gomera. The company announced on Wednesday that it anticipates finishing all the infrastructure by the end of this year.

Project Overview

The dual circuit installation commenced on August 29 and was carried out through two crossings from San Sebastián de La Gomera to Punta Blanca in Tenerife. Red Eléctrica used the cable ship Cable Enterprise from Prysmian’s fleet, which has finished ahead of schedule thanks to favourable sea conditions in the area.

Next Steps

Two more campaigns to protect the cables are set to occur between autumn and early winter, along with the connection of the cables in the transition chambers and testing scheduled for November.

Challenges and Specifications

Red Eléctrica emphasises that the project has been “a challenge” in both design and execution. The underwater section spans approximately 36 kilometres at a maximum depth of 1,145 metres, making it the world’s deepest 66 kV three-polar alternating submarine link. This required a specially designed and reinforced cable made from lightweight materials to withstand the demanding conditions of the installation environment.

The project also posed challenges in ensuring the protection of the biodiversity in shallower waters, due to the unique nature of the heterogeneous volcanic soils. To address this, a directed drilling technique was employed, which introduced the cable into the sea through a micro-tunnel with an exit hundreds of metres from the shore.

Infrastructure Developments

Additionally, the infrastructure includes two completely underground land sections in La Gomera and Tenerife, as well as two new substations: El Palmar in La Gomera and Chío in Tenerife. The former has recently been completed, while the latter has been operational since early 2025.