CN ALMARAZ 1 — Spain

CN ALMARAZ 1 is a 2,093 MW nuclear power station in Extremadura, Spain. It is operated by IBERDROLA GENERACION S.A.. Based on reported annual generation of 16,344 GWh, it can supply roughly 4.7 million homes. It ranks #1 of 899 Spain power plants by installed capacity. Commissioned in 1984, it is around 42 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, nuclear supplies about 18.8% of Spain's electricity; the national grid averages 154 gCO₂/kWh (74.6% low-carbon) (2025).

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1006358.

Data provenance

Source of the capacity and fuel values:

capacity: GEM · 2026 · L100000500113; fuel: WRI GPPD

In context: how this plant compares

At 2,093 MW, CN ALMARAZ 1 is well above the median nuclear plant in Spain (1,087 MW). Nuclear plants split uranium to raise steam with no direct CO₂; they run as steady baseload with very high capacity factors and the longest operating lifetimes of any thermal plant.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Key facts

Load factor

89%, from 16,344 GWh of reported generation; the median for 5 nuclear plants in Spain that report generation is 85%

Generation trend

16,027 GWh in 2015 and 16,344 GWh in 2017 (+2%)

Highest and lowest year

2017: 16,344 GWh; 2016: 15,053 GWh

Share of Spain nuclear capacity

17.5% of 11,959 MW across 10 plants in this dataset

Age among peers

3 of 7 dated nuclear plants in Spain are older

Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).

Reported generation trend

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by IBERDROLA GENERACION S.A.. All plants by this company →

Local climate & thermal context

This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a hot-summer Mediterranean climate (Köppen Csa) — Northern Hemisphere, latitude 39.8°N — which shapes how much energy it can produce and how its output varies through the year.

Monthly mean temperature

Heating degree-days here run 34% below the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.

Climate heat-demand index: 36/100 — this site sits in the mid third of the power plants we cover by heating degree-days.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

Site climate & environmental severity

This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with humidity / wetness the leading environmental stress.

Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.

How it compares & nearby plants

The #1 largest nuclear power plant of 10 in Spain by capacity.

Spain has 10 nuclear power plants in this dataset, together about 11,959 MW of capacity.

Nearby power plants

• Almaraz · Solar · 22.1 MW · Extremadura
• VALDECANAS 3 · Hydro · 249 MW · Extremadura
• Casatejada · Solar · 11.3 MW · Extremadura
• MAJADAS · Solar · 49.9 MW · Extremadura
• Talayuela 1 · Solar · 10 MW · Extremadura
• Don Quijote · Solar · 17.8 MW · Castille-La Mancha

Location

Coordinates 39.807, -5.6986 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions