Spain’s national electricity demand grew by 2.6% in December compared to the same month last year, after adjusting for the effects of temperature and working patterns. In gross terms, demand is estimated at 22,582 GWh —4.2% higher than in December 2024. In addition, self-consumption facilities are estimated to have generated 709 GWh during the month, representing a 3.0% impact on national demand.

Year-to-date, Spain has recorded a demand of 255,759 GWh, 2.7% higher than in the same period of 2024. Once again, after adjusting for the effects of working patterns and temperatures, demand increased by 1.5% compared to the same period of the previous year. For full-year 2025, self-consumption facilities are estimated to have generated 13,485 GWh during the month, representing a 5.0% impact on national demand.

Renewable generation in December totalled 11,361 GWh, 5.2% more than in December 2024. This represents 48.9% of total electricity generation based on currently available data. The estimated contribution from self-consumption facilities during this period increases this share to 49.5%.

Moreover, this month, 69.7% of electricity generation came from technologies that do not emit CO₂ equivalent.

Wind power was the leading source, generating 5,379 GWh —23.2% of the total— and 1.5% more than in the same month last year. Combined-cycle generation ranked second, with a 21.0% share, followed by nuclear at 20.7%.

Hydropower output increased by 32.1% compared to December 2024, reaching 3,260 GWh and accounting for 14.0% of total generation nationwide. 

In 2025, renewables accounted for 55.5% of Spain's total energy mix. This figure is in line with the year-end forecasts published by Red Eléctrica. When estimated self-consumption is included, this final share rises to 56.6%. In terms of energy generated, renewable production exceeded 150.8 TWh, marking an all-time high.

During the final month of the year, energy storage technologies enabled the integration of 605 GWh into the Spanish electricity system, helping optimise the use of renewable electricity generation. Additionally, 380 GWh of electricity were scheduled for export to neighbouring countries.

The electricity system in Islas Baleares and Islas Canarias

Electricity demand in Islas Baleares decreased by 0.9% in December after adjusting for the effects of temperature and working patterns. In absolute terms, monthly demand was estimated at 452,727 MWh, at levels similar to the previous year. 
For the full year 2025, electricity demand in Islas Baleares totalled 6,287,101 MWh, a 3.7% increase compared to the same period of 2024. 

Combined-cycle generation accounted for 75.9% of the energy produced in  Islas Baleares, which reflects the island’s main source this month. Renewable energy generation represented 9.8% of the Balearic electricity mix. Additionally, this December, the submarine link between the Peninsula and Mallorca helped cover 26.5% of Islas Baleares' electricity demand. 

Meanwhile, in Islas Canarias, electricity demand rose by 1.1% compared to the same month in 2024, after adjusting for the effects of working patterns and temperatures. This represents an estimated gross demand of 767,139 MWh, marking a 1.3% increase compared to December of last year. 

In 2025, total demand in Islas Canarias reached 8,995,924 MWh, which was 1.1% higher than in the same period of the previous year. 
In terms of electricity generation in Islas Canarias, the combined cycle was also the leading source in December—with 46.1% of the total. Renewables represented 15.5% of total generation.