CASTRO II is a 195.3 MW hydro power station in Castille and Leon, Spain. It is operated by IBERDROLA GENERACION S.A.. Based on reported annual generation of 182 GWh, it can supply roughly 52k homes. It ranks #99 of 899 Spain power plants by installed capacity. Commissioned in 1977, it is around 49 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 11.4% 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 WRI1006321.
Data status
Known data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Capacity provenance
The public capacity above is the current source-record value. A 2026 tracker candidate lists 83 MW for Castro I hydroelectric plant, but it is not used as the public primary value until scope is verified (unit vs operating vs installed/project total).
Data provenance
Capacity and fuel are the upstream open-dataset record, not yet matched to a 2026 registry or GEM entry.
capacity: WRI GPPD; fuel: WRI GPPD
In context: how this plant compares
At 195.3 MW, CASTRO II is well above the median hydro plant in Spain (55.2 MW). Technically it is described as conventional storage. Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Key facts
- Load factor
- 11%, from 182 GWh of reported generation; the median for 11 hydro plants in Spain that report generation is 7%
- Generation trend
- 358 GWh in 2015 and 182 GWh in 2017 (−49%)
- Highest and lowest year
- 2016: 426 GWh; 2017: 182 GWh
- Share of Spain hydro capacity
- 1.2% of 15,680 MW across 124 plants in this dataset
- Age among peers
- 82 of 116 dated hydro 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 hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a warm-summer Mediterranean climate (Köppen Csb) — Northern Hemisphere, latitude 41.6°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 5% 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: 48/100 — 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 #24 largest hydro power plant of 124 in Spain by capacity.
Spain has 124 hydro power plants in this dataset, together about 15,680 MW of capacity.
Nearby power plants
- Sayago nuclear power plant · Nuclear · 1,075 MW · Zamora
- RICOBAYO II 1 · Hydro · 326.6 MW · Castille and Leon
- P. E. EL HIERRO · Wind · 38.4 MW · Castille and Leon
- Pereruela · Solar · 9.9 MW · Castille and Leon
- VILLANUA · Hydro · 10.9 MW · Castille and Leon
- VILLARINO 4 · Hydro · 850.9 MW · Castille and Leon
Location
Coordinates 41.5756, -6.1891 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is CASTRO II?
CASTRO II is a 195.3 MW hydro power plant in Castille and Leon, Spain, commissioned in 1977.
How much electricity does CASTRO II generate?
CASTRO II generates about 182 GWh of electricity per year.
Who operates CASTRO II?
CASTRO II is operated by IBERDROLA GENERACION S.A..