Every time we turn on a light, connect a computer, or charge an electric car, we trust that electricity will arrive instantly, reliably, and safely. But we rarely ask ourselves how that invisible network that supports our daily life actually works.
The Spanish power grid is one of the most advanced in Europe, but also one of the most complex, with multiple players involved in generation, transmission, distribution, and operation. Understanding who is in charge is not just useful for experts: in an era of energy transition, it’s almost essential knowledge.
Electricity Generation: The First Step
Everything starts with generation, that is, the production of electricity in different power plants. In Spain, the current energy mix is dominated by renewables, but still includes gas, nuclear, and hydro.
Generators are private or semi-public companies that produce electricity and sell it on the wholesale market. The main generators in the country include:
- Iberdrola (leader in wind and nuclear)
- Endesa (strong in hydro, nuclear, and gas)
- Naturgy (specialized in gas and renewables)
- Acciona Energía (100% renewables)
- EDP, Repsol, Capital Energy, and other emerging players.
Every day, these companies bid to sell their electricity through the Iberian Energy Market Operator (OMIE), in a price-matching process that determines how much electricity will cost consumers.
In summary: generators produce, but they don’t run the system. Their role is vital, but they don’t manage the real-time flow.
High-Voltage Transmission: The Invisible Highways
Once generated, electricity needs to travel hundreds of kilometers to reach consumption points. This high-voltage phase is centralized in a single player: Red Eléctrica de España (REE).
REE is the sole operator and transporter of the Spanish power system. Its responsibility is twofold:
- Transport electricity through high-voltage networks (220 kV and 400 kV).
- Guarantee the real-time balance between generation and demand.
This makes REE the true brain of the system. From its Control Center (CECOEL) in Madrid, it monitors everything happening on the peninsular, Balearic, and Canary grids 24/7.
In practical terms: REE does not generate electricity or sell it to end users. But without its coordination and transmission work, the system would collapse in minutes.
Distribution: The Last Mile
When electricity reaches substations, it needs to be stepped down to be usable. Here, distribution comes into play, a task carried out by specialized companies managing medium and low voltage networks.
The main distributors in Spain are:
- e-distribución (Endesa)
- i-DE (Iberdrola)
- UFD (Naturgy)
- Viesgo, E-Redes, and other local operators.
Each distributor is responsible for its geographic area, managing maintenance, expansion, and digitalization of the network. They also handle outages, install smart meters, and connect new self-consumers.
Important: distributors cannot sell electricity directly to consumers. That’s the job of retailers.
Retailers: The Ones Who Bill Us
Although many consumers associate their electricity bill with a brand (Endesa, Iberdrola, Naturgy, Repsol…), they are actually dealing with retailers, not generators or distributors.
Retailers buy electricity on the wholesale market and resell it to consumers, offering different rates and services. There are:
- Regulated retailers (like Energía XXI or Curenergía), offering the Voluntary Price for Small Consumers (PVPC).
- Free market retailers, offering flat rates, time-of-use rates, or certified green energy.
So, the chain is complete: the generator produces, REE transmits, the distributor brings electricity to your home, and the retailer bills you.
Who Really Runs the Spanish Power Grid?
Power in the Spanish grid is distributed, but the key player is Red Eléctrica de España (REE).
REE manages the system: it decides which plants turn on or off, how renewable generation is balanced, how energy is exported or imported to France, Portugal, or Morocco.
REE plans the future development of the grid through long-term investment plans, approved by the government.
REE coordinates emergencies, such as recovery after blackouts or managing frequency drops.
Although the Ministry for the Ecological Transition and Demographic Challenge sets the basic rules and strategic plans, it is REE that operates the grid day-to-day with full technical independence.
Additionally, bodies like the National Commission on Markets and Competition (CNMC) oversee that all players (generators, distributors, retailers) fulfill their obligations and do not abuse their position.
A Rapidly Changing System
The Spanish power grid is undergoing unprecedented transformation:
- More renewables: the growth of solar and wind requires managing more variable and distributed generation.
- Self-consumption and storage: more consumers generate their own electricity and feed it into the grid.
- Grid digitalization: smart meters and advanced control systems allow finer management, but also pose new cybersecurity risks.
- European interconnections: Spain is working to increase its electrical connection with France and the rest of Europe, reducing its “energy isolation.”
These changes force all players—generators, REE, distributors, retailers—to adapt continuously. The goal: electricity always arrives when and where it’s needed, cleanly and safely.
Sources:
- Red Eléctrica de España (REE) – How the Spanish power system works
- Iberian Energy Market Operator (OMIE) – How the wholesale electricity market works
- CNMC (National Commission on Markets and Competition) – The electricity sector in Spain
- Endesa – Electricity transmission and distribution: what they are and how they work
- El Periódico de la Energía – Who runs the Spanish power grid
