ENERGY MIX IN SPAIN

The importance of a balanced energy mix to keep Spain's electricity system competitive and safe

A diversified energy mix will be essential for Spain and the world to meet the growing demand for energy, drive a sustainable economy based on renewables and meet international commitments to reduce carbon emissions.

The Cortes-La Muela hydroelectric complex, located in the municipality of Cortes de Pallás, Valencia, in the Júcar River basin.

When talking about a nation's energy security, the term energy mix always comes up because of the importance of its influence on people's lives. Depending on the type of energy mix, a country may face various changes: fluctuations in energy prices, increased dependence on third parties or even negative effects on the climate, such as an increase in the frequency of extreme weather events.

Planning an energy mix that is able to minimise its environmental impact and ensure the availability of energy in the long term is therefore essential.

What’s the energy mix and why is it key to the Spanish electricity system?

The energy mix is understood as the set of energy sources used in a given geographical area to cover the energy needs of the users living there. These sources may include non-renewable resources, such as natural gas, or inexhaustible natural resources, such as the sun, water and wind, which represent the basis of renewable energies.

A more diversified and balanced energy mix also contributes to a more competitive energy market. As a consequence, countries obtain positive results for their economies, such as greater price stability for consumers or less dependence on external resources.

In Spain, we benefit from an increasingly balanced energy mix. Recent years have seen a significant shift towards a greater share of renewables in our power generation, with particular growth in onshore wind and solar. This transition is playing a key role in reducing CO2 emissions, boosting electrification and strengthening the resilience of the electricity system, positioning Spain as one of the leaders in renewables in Europe.

Current composition of the energy mix in Spain

In recent years there has been considerable development of renewable technologies in Spain. So much so that the share of green production in the Spanish mix set a new record in 2024: almost 57% of all generation comes from renewable sources, a figure higher than the share recorded the previous year (51.2% in 2023).

Wind and solar energy sources play an important role in Spain's energy mix, but in addition to these, other sources also have significant weight, in this case synchronous generation energy, such as hydroelectric and nuclear power. Synchronous energy sources operate at a constant speed and maintain the same frequency as the power grid, thus providing greater guarantee of stability to the electrical system.

According to data from the latest Electricity System Report, published annually by Red Eléctrica de España (Spain’s Electrical Grid), wind-generated energy has once again been the main source of electricity generation in our system for the second year running, contributing 23.2% of total energy consumed. It is followed by nuclear (20%) and solar photovoltaic (17%).

Below is a detailed breakdown of the distribution of energy sources in the current energy mix.

The distribution of energy sources in the Spanish energy mix (Source: Red Eléctrica de España - 2024 Electricity System Report)

Renewable and non-renewable sources in 2024

The Spanish electricity system has once again confirmed the upward trend of renewable energies, which is consolidating thanks to onshore wind and solar photovoltaic. However, some synchronous generation technologies, such as hydroelectric and nuclear, continue to cover a large part of the population's demand, and are fundamental to the system’s reliability. The most important sources in Spain in the last year were:

Onshore wind

The most important renewable source in terms of its contribution to generation, wind power transforms the movement of wind currents into electricity through wind turbines’ blades. Its role in the medium and long term is fundamental to achieving decarbonisation targets.

Nuclear

It provides electricity through the fission of uranium in nuclear reactors, and is considered a stable and reliable source, since it doesn’t depend on atmospheric weather conditions. It is therefore capable of giving the electricity system inertia and providing an immediate response to grid disturbances or fluctuations.

Solar photovoltaic

It uses solar radiation to produce electricity from the photoelectric effect. It is one of the most promising and environmentally friendly renewable energy sources. In the case of Spain, its geographical location offers ideal conditions for making the most of the abundant solar resource available.

Combined cycle

Combined cycle power generation is produced by combining a gas turbine and a steam turbine using natural gas. Like nuclear and hydroelectric plants, it offers synchronous generation and inertia, which stabilises the system. Its main function is to make operation more flexible and as back-up generation when other sources are not available, at least until large-scale storage technologies such as pumped-storage plants are more widely deployed.

Hydroelectric

It harnesses the kinetic and potential energy of waterfalls along a river to convert it into renewable electricity. Spain's hydropower plants have been contributing to the diversification of the national energy matrix for years as a key synchronous technology for the transition to a more resilient energy system. Pumped-storage plants, for example, are the most efficient and cost-effective renewable option for large-scale storage.

Evolution of the energy mix over the last decade

The energy data of the last decade is proof that more and more electricity is being generated from clean sources in Spain. As can be seen in the graph below, since 2023 renewables have accounted for more than half of all annual electricity generation.

Evolution of the Spanish energy mix in recent years (Source: Red Eléctrica)

The role of Spain's energy mix in the energy transition

The energy transition broadly focuses on the transformation of the current energy system to a model based on renewable sources. This is where the importance of a diversified and balanced energy mix comes into play, capable of guaranteeing this new system’s stability.

If you look closely at the situation in Spain, you’ll see that renewables’ presence in its energy supply has growing. This reveals that the transition towards a cleaner system is advancing by leaps and bounds in Spain, which is gradually reducing its dependence on fossil fuels.

Electricity grids, key to connecting renewables to demand

The electricity grid we currently have in Spain is not a structure unrelated to the country's generation sources. As the backbone of our energy system, electricity grids play a key role in transporting electricity from production centres to end users. Without them, it wouldn’t be possible to supply homes, factories, offices and hospitals with power.

In recent years, the electricity sector has made a huge effort to replace emitting power plants with renewable generation plants. The real challenge now is to electrify other energy uses, such as heat generation and transport, which still depend on burning gas and oil. We need to continue to invest in electrification and to develop and expand the electricity grid so that clean energy can reach the consumer. Today’s lack of grid connection capacity is a major bottleneck slowing down the energy transition and the economy’s decarbonisation.

Furthermore, a key element at present is the stagnation of demand in contrast to the growth of renewables in recent years. Therefore, the effective solution is to boost and increase demand through the development of electric vehicles, the electrification of industry and heating. For all of this, electrical grids play an essential role.

That’s why the European Commission says in its Grid Action Plan that an investment of €584B is needed in grids by 2030 in order to accommodate more renewables. The entry of clean energies into the energy mix requires a modern and flexible infrastructure capable of integrating the different generation technologies together with the electrification of demand.