Red Eléctrica, the Redeia company responsible for the operation and transmission of Spain’s electricity systems, has commissioned the new 132 kV underground line between the Ibiza and Bossa substations. Together with the new Sant Jordi 132 kV substation and other related repowering or voltage-shifting projects on existing lines, this line constitutes the main infrastructure of the so-called Southern Axis. This is a set of projects for Ibiza’s transmission network that reinforce the security and quality of supply to the island and will allow progress in its energy transition.

To commemorate the commissioning of this key axis for the island, the president of Redeia, Beatriz Corredor, received Alejandro Sáenz de San Pedro, the Minister of Business, Self-Employed Workers, and Energy of the Balearic Islands Government; Ignacio Andrés Roselló, the Minister of Environmental Management, Sustainability, Innovation, and Transparency of the Ibiza Island Council; and Vicent Roig, the mayor of Sant Josep de Talaia. There, they learned about all aspects of the project from Asunción Borrás, the Substation Coordinator of Red Eléctrica; Francisco Menéndez, the head of the Balearic Islands division of Red Eléctrica; and José Ignacio Granados, the project director. A working meeting was held beforehand, which was also attended by Vicent Marí Torres, the president of the Ibiza Island Council.

The new infrastructure, which represents an investment of €35 million, represents a more sustainable alternative to the previous Es Fornàs project. Its design and execution were developed through consensus between Red Eléctrica, the General State Administration, the Balearic Government, and the island’s local and regional governments (primarily the Ibiza Council and the City Councils of Ibiza and Sant Josep). This Southern Axis is electrically equivalent to the previous project, avoiding the need for a double overhead circuit that crossed the island from east to west, as well as the construction of a new 132 kV outdoor substation in Sant Antoni.

The overall project is included in the current 2021-2026 Electrical Planning Plan, approved by the Council of Ministers and binding on Red Eléctrica. The new underground line between Ibiza and Bossa, a 4.7-kilometer 132 kV double circuit, and a new 132 kV transmission line adjacent to the existing 66 kV line at the Sant Jordi substation are the most notable infrastructure projects already operational along the Southern Axis.

The comprehensive project

Previously, as part of this comprehensive project, Red Eléctrica had completed the repowering of existing transmission lines. This intervention responds to Red Eléctrica’s strategy of maximizing the use of existing lines and thus avoiding the construction of new power lines. First, the lines in the north of the island (Santa Eulària-Sant Antoni) were repowered, followed by the lines 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 of the lines has increased their transmission capacity by between 15% and 35%.

In addition, DLR ( Dynamic Line Rating ) devices have been installed on two of these lines. This IoT-based technology improves their safe operation and guarantees a constant power supply. The DLR systems are composed of sensors and weather stations that capture various conductor parameters and environmental data, advanced communication systems, and artificial intelligence algorithms that allow the lines’ carrying capacity to be calculated in real time and their use optimized.

They have been installed on the 66 kV overhead line between the Ibiza and Bossa substations (where 7 meteorological stations and 19 sensors have been installed on the line supports) and on the 66 kV line between the Ibiza and Sant Antoni substations (with 8 stations and 20 sensors).

The Southern Axis projects decisively strengthen the quality and security of electricity supply to the island of Ibiza as a whole, and specifically to the southern and western areas. Its commissioning prevents situations of real risk to the supply in the event of the untimely 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 elements in the transmission grid currently under construction, will complement the South Axis and maximize the contribution of the existing submarine electrical link with Mallorca, enhancing the benefits of the entire Balearic electrical system interconnected with itself and with the peninsula (reduction of local fossil fuel generation needs, cost savings for the system, reduction of CO ₂ emissions and increase in the penetration of renewable energies).