Red Eléctrica, the Redeia company responsible for the operation and transmission of Spain’s electricity systems, has brought into service the new 132 kV underground line between the Eivissa and Bossa substations. Together with the new 132 kV Sant Jordi substation and other related works, including the upgrading or voltage conversion of existing lines, these are the main infrastructures that make up the so-called Southern Axis. This set of transmission grid projects in Ibiza strengthens the security and quality of the island’s electricity supply and will contribute to progress in its energy transition.

To mark the commissioning of this key axis for the island, Redeia’s Chairwoman, Beatriz Corredor, welcomed the regional minister of Business, Self-Employment, and Energy of the Government of the Balearic Islands, Alejandro Sáenz de San Pedro, the regional minister of Environmental Management, Sustainability, Innovation and Transparency of the Ibiza Council, Ignacio Andrés Roselló, and the mayor of Sant Josep de sa Talaia, Vicent Roig, to the Sant Jordi substation. There, they were given a detailed overview of the project by Red Eléctrica’s Substation Coordinator, Asunción Borrás, along with the head of Red Eléctrica's Balearic Islands division, Francisco Menéndez, and the project manager, José Ignacio Granados. A working meeting was also held earlier, attended by the chairman of the Ibiza Island Council, Vicent Marí Torres.

The new infrastructures, totalling an investment of 35 million euros, offer a more sustainable solution compared to the former Es Fornàs project. Their configuration and implementation have been jointly coordinated by Red Eléctrica, the Spanish Central Government, the Balearic Government, and the island’s regional and local authorities (primarily the Ibiza Island Council and the Municipalities of Eivissa and Sant Josep). This Southern Axis is electrically equivalent to the previous project, but avoids the construction of a double-circuit overhead line that would have crossed the island from east to west, as well as the need to build a new 132 kV outdoor substation in Sant Antoni.

The overall project is part of the current 2021–2026 Electricity Planning, approved by the Council of ministers and binding for Red Eléctrica. The new underground line between Eivissa and Bossa (a 4.7 km, 132 kV double circuit), as well as a new 132 kV switchyard adjacent to the existing 66 kV one at the Sant Jordi substation, are the most prominent and now operational infrastructures of the Southern Axis.

A comprehensive project

Previously, as part of this comprehensive project, Red Eléctrica had already completed the repowering of existing transmission lines. This intervention is in line with Red Eléctrica's strategy of maximising the use of existing lines to avoid the construction of new overhead lines. First, the lines in the north of the island (Santa Eulària–Sant Antoni) were repowered. This was followed by those that cross the island from east to west and those in the south (Eivissa–Sant Antoni/Eivissa–Bossa and Sant Jordi–Sant Antoni). The repowering increased the transmission capacity of these lines by between 15% and 35%. 

In addition, DLR (Dynamic Line Rating) devices have been installed on two of these lines. This technology, based on IoT, enhances system operation under safe conditions while ensuring a continuous electricity supply. DLR systems consist of sensors and weather stations that collect various parameters from the conductors, as well as data on environmental conditions, advanced communication systems, and AI-powered algorithms that calculate the real-time transmission capacity of the lines to optimise their usage.

They have been installed on the 66 kV overhead line between the Eivissa and Bossa substations (where 7 weather stations and 19 sensors have been mounted on the power line towers), and on the 66 kV line between the Eivissa and Sant Antoni substations (with 8 stations and 20 sensors). 

The actions taken as part of the Southern Axis project significantly strengthen the quality and security of electricity supply for the entire island of Ibiza, particularly in its southern and western areas. The commissioning of this infrastructure helps avoid situations of real risk to the electricity supply in the event of an unexpected disconnection of single or double-circuit lines in Ibiza. 

The future installation of energy storage batteries on land adjacent to the existing Sant Antoni substation (as fully integrated components of the transmission grid, currently under construction) will complement the Southern Axis and maximise the benefits of the existing submarine electrical link with Mallorca. This will enhance the advantages for the entire Balearic Islands electricity system, which is interconnected both internally and with the Spanish peninsula. Benefits include a reduced need for fossil-fuel-based local electricity generation, system cost savings, CO₂ emission reductions, and increased penetration of renewable energy sources.