CASTRO II is a 195 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.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
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).
Capacity claim grade: D_REJECT_KEEP_MASTER - recommended action: keep_master - confidence: rejected_candidate. This follows a claim-based data model: value + scope + source + confidence, rather than silently overwriting records.
The capacity and fuel fields on this page are source-record values from the upstream open dataset. They are useful for identification and ranking, but they have not been upgraded to a 2026 registry/GEM-location verified value.
capacity: WRI Global Power Plant Database source-record (legacy); fuel: WRI source-record fuel
At 195 MW, CASTRO II is well above the median hydro plant in Spain (55 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.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by IBERDROLA GENERACION S.A.. All plants by this company →
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.
For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with humidity / wetness the leading environmental stress.
Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.
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.
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.
Coordinates 41.5756, -6.1891 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
CASTRO II is a 195 MW source-record hydro power plant in Castille and Leon, Spain, commissioned in 1977.
CASTRO II generates about 182 GWh of electricity per year.
Its output is enough to supply roughly 52,085 homes.
CASTRO II is operated by IBERDROLA GENERACION S.A..
