Installed Power Capacity vs. Energy Generation by Technology in Spain

Analyzing the balance between potential and actual energy production of Spain’s energy portfolio.


With the global transition towards renewable energy and the pressing need to reduce carbon emissions, understanding the energy capacities and the mix of technologies is crucial.

With its varied landscape, Spain offers an excellent opportunity to study the balance between renewable and non-renewable energy sources.

This article presents an overview of the installed power capacity of the technologies that generate electricity in Spain, analyzing the potential, demand, and efficiency.


Each row of the following dataset represents the energy (electricity) that different technologies, such as Hydroelectric, Combined Cycle, and Nuclear, generate per hour in one year.

The data is provided by Red Eléctrica de España (REE), Spain’s Grid Operator, via ESIOS API. Learn how to download the data automatically with this video.

Dataset. Energy generation in Spain for one year


  • What percentage of Spain’s energy comes from renewable sources?
  • Are renewable energies capable of meeting Spain’s energy demand on their own?
  • What challenges do renewable energies pose in terms of reliability and consistency?
  • Which energy technology makes the most efficient use of its installed capacity?

While you read this article, remember we have created a video tutorial to uncover the programming steps behind the analysis and visualizations you observe.


Installed Power Capacity

How much electricity could Spain generate during any given hour?

Spain has an installed power capacity of 119 GWh, according to the official grid operator Red Eléctrica España (REE).

61% of energy comes from renewable sources such as Eolic and Photovoltaic Solar.

Figure 1. Installed power capacity by technology in Spain (2022-12) | Interactive Chart

Hourly Energy Demand

Nevertheless, Spain doesn’t need 119 GWh in any hour; the minimum and maximum electricity demand for any given hour is 16 and 44 GWh, respectively, with an average of 30.

For the following explanations, 30 GWh will be the baseline reference for any given hour.

Figure 2. Distribution of hourly energy generation in Spain | Interactive Chart

Energy Generation by Technology

Based on installed power capacity, Eolic (29 GWh) could generate the demand of a complete hour without any other technology involved.

Unfortunately, since the wind does not always blow, Eolic energy cannot have exclusivity; more energy sources are required, both renewable and non-renewable.

Why is it not enough to rely on renewable energy sources?

They are unstable: generating renewable energy sources is not always guaranteed due to climatological conditions.

For example, if the wind stops blowing, the Eolic energy generation will be zero.

A concrete example: what happens if a Photovoltaic Solar plant in Seville is expected to generate 1 GWh in the next hour, and some clouds suddenly make it impossible? Which energy source could be the alternative?

Combined Cycle (26GWh) is a viable option because it generates electricity from gas. This gas-based generation provides a consistent and dispatchable power source, ensuring the grid always has available electricity without risking oversupply or undersupply.

In conclusion, renewable and non-renewable energy sources must dance with one another to guarantee the grid’s stability and safety.

Figure 3. Hourly average of the energy generation mix in Spain | Interactive Chart

Utilization Ratio by Technology

If all the energy from each technology cannot be used at the same time, which one of them takes more advantage of their installed power capacity?

Based on the ratio of actual energy generated to the maximum potential energy that could be produced in a year, Nuclear energy emerges as the most efficient, with a ratio of 0.89.

The maximum potential energy is calculated with the maximum generation of technology per hour and multiplied by the number of days within the sample.

Figure 4. Energy utilization by technology in Spain | Interactive Chart


Spain’s current energy landscape reveals a notable mix of renewable and non-renewable energy sources, each contributing distinct advantages and challenges to the power grid. While renewable sources such as Eolic energy have substantial installed capacities, their variability based on climatic conditions necessitates a complementary role from non-renewable sources like Combined Cycle to ensure consistent energy availability.

The data also underscores the importance of Nuclear energy in terms of utilization efficiency, given its high ratio of actual to potential energy generation. Such insights highlight the complexity and intricacy of managing a national power grid with diverse energy sources.

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Jesús López

Statistics, cloud and data programmer @datons

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