VALLE SECOLO is a 114 MW geothermal power station in Tuscany, Italy. Based on reported annual generation of 798 GWh, it can supply roughly 228k homes. It ranks #152 of 489 Italy power plants by installed capacity. Commissioned in 1981, it is around 45 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, geothermal supplies about 2.1% of Italy's electricity; the national grid averages 285 gCO₂/kWh (48.8% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1002978.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
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 114 MW, VALLE SECOLO is well above the median geothermal plant in Italy (19 MW). Geothermal plants tap underground heat to raise steam for a turbine; they provide steady, low-carbon baseload but are limited to geologically active regions.
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).
This geothermal plant taps underground heat to raise steam that drives a turbine. It sits in a hot-summer Mediterranean climate (Köppen Csa) — Northern Hemisphere, latitude 42.2°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 41% 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: 33/100 — this site sits in the bottom 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 an aggressive, high-corrosion environment (estimated ISO 9223 class C5 — Very high), with marine salt corrosion 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 #1 largest geothermal power plant of 33 in Italy by capacity.
Italy has 33 geothermal power plants in this dataset, together about 857 MW of capacity.
Coordinates 42.2362, 10.8674 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
VALLE SECOLO is a 114 MW source-record geothermal power plant in Tuscany, Italy, commissioned in 1981.
VALLE SECOLO generates about 798 GWh of electricity per year.
Its output is enough to supply roughly 227,971 homes.
