GRAND MAISON is a 1,690 MW hydro power station in Rhone-Alpes, France. Based on reported annual generation of 2,085 GWh, it can supply roughly 595,800 homes. It ranks #21 of 2,188 France power plants by installed capacity. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 10.4% of France's electricity; the national grid averages 41 gCO₂/kWh (94.9% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1002734.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a subpolar oceanic climate (Köppen Cfc) — Northern Hemisphere, latitude 45.1°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 97% above 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: 93/100 — this site sits in the top third of the power plants we cover by heating degree-days.
In colder climates, uninsulated hot equipment (boilers, turbines, valves, steam lines) loses proportionally more heat to ambient air — exactly the loss Inzonex modular insulation is designed to cut.
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.
The #1 largest hydro power plant of 429 in France by capacity.
France has 429 hydro power plants in this dataset, together about 19,506 MW of capacity.
Coordinates 45.146, 6.051 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
