Solar output by French département

The ranking, sunniest first

At the top: Bouches-du-Rhône (1,558), Vaucluse (1,538), Var (1,517), Alpes-de-Haute-Provence (1,468), Gard (1,464) kWh per kWp. At the bottom: Nord (1,086), Ardennes (1,089), Seine-Maritime (1,100), Pas-de-Calais (1,105), Moselle (1,109) kWh. The Mediterranean rim and the southern Alps lead; the Channel coast and the far north close the list. The roughly 40% north-south gap shows up almost entirely in a system’s output, but much less in its return: a household in Lille uses as much daytime power as one in Marseille, and that consumption drives most of the gain.

The regions

Each region has its own page, with the calculator opened on its largest city and a breakdown of its départements: for instance Provence-Alpes-Côte d’Azur, Occitanie or Île-de-France.

How these figures are produced

PVGIS was queried on a grid of points 0.2 degrees apart (about 20 km) covering the country, for one kilowatt-peak of crystalline silicon modules tilted at 35° due south, with 14% losses (cabling, inverter, soiling). Each commune takes the value of the point nearest its centre; a département’s median is that of its communes, not weighted by population. Details and limits are on the method and sources page.

The payback column assumes a roof at 30° due south, a household using 4,500 kWh a year without electric heating, the Tarif Bleu of 1 August 2026 and an estimated installed price, with no rise in electricity prices. These are shared assumptions for comparing départements, not a forecast for your home.