45,000 km of cables across the country: what is Red Eléctrica?

BarcelonaRed Eléctrica Española (REE), of the Redeia group, is the company that we call the system operator, and which has been singled out by Monday's massive blackoutWithin the Spanish coalition government itself, Sumar has asked that the State have a greater influence in the company, but in fact already controls it. It is the largest shareholder, with 20% of the capital (the remaining shareholders hold no more than 5%), through the State Industrial Participation Company (SEPI). The president of Red Eléctrica is former Socialist minister Beatriz Corredor.

The company is responsible for transporting the energy produced in power plants through high or very high voltage lines to the grid of distribution companies, in the case of Catalonia, primarily Endesa, which transports it to the end customer through a medium and low voltage network. To transport electricity, Red Eléctrica has 45,000 kilometers of cables and hundreds of electrical substations. For example, in Catalonia it recently opened a large substation to supply electricity to the port of Barcelona and another to Abrera. which should allow the electrification of the Seat plant in Martorell.

According to the company's public data, the Red Eléctrica network has 45,706 kilometers of cabling lines. Of these, 43,498 kilometers are overhead lines (95.17%), 1,262 are underground cables (2.76%), and 945 (2.07%) are submarine cables. Through this network, high-voltage electricity, at 400 kilovolts (kV), is transported to substations, where it is transformed into lower-voltage electricity. To control this, Red Eléctrica has a mastermind, known as the Electrical Control Center (Cecoel), located in Alcobendas (Madrid), which analyzes and processes nearly 240,000 pieces of data every second.

What is known about the blackout?

Although experts, the company, and the Spanish government itself say it will likely take months to determine what caused the blackout, there is already some information about what happened. Sources from the Ministry for Ecological Transition emphasize that on Monday the system was stable in terms of two key variables: voltage and frequency. However, when the frequency fell below a certain threshold on the Spanish side, the interconnection relays automatically tripped for protection, and the Peninsula was isolated from France.

This event is apparently consistent with a loss of power generation in the southwest region, believed to be in Extremadura, which caused voltages and a frequency variation that stabilized 1.3 seconds later. However, at that same moment, another event was observed, causing another oscillation that could no longer be controlled and that gradually amplified. The contagion effect was rapid, leading to the general blackout.

Regulated company

Red Eléctrica, as the system operator, is supervised by the National Commission of Markets and Competition (CNMC) and is regulated at both the state and European levels. This regulation also affects its investment and grid expansion plans. In addition to transporting electricity, it must also operate the system. In other words, since electricity is practically not stored, it must ensure that generation and consumption are always balanced.

The company closed 2024 with a net profit of €388 million.46.6% less than the previous year. According to its report to shareholders, in 2024 it invested €1,104.9 million in the transmission grid and operation of the electrical system, which is 34% more than in 2023. A large part of this volume (€976.3 million) went to the development and reinforcement of the transmission grid in Spain. Of note are investments to strengthen interconnections with neighboring states and between systems. Work on the link that will unite Spain and France across the Bay of Biscay is progressing after receiving the necessary authorizations in 2024. This is also the case with the new interconnection with Portugal to the north (Galicia).

The day after the massive blackout, Red Eléctrica presented its results for the first quarter of 2025. The company's net profit rose 4.2% between January and March, to €137.8 million. In the first three months of the year, Red Eléctrica invested €236.8 million, 70% more than the previous year. Of this amount, €217 million went to the transmission grid. The company states that it expects to exceed €1.4 billion in investment in the electricity system operator this year as a whole.