Solar panels in Auvergne-Rhône-Alpes
The calculator opens on Lyon. In this region two neighbouring communes can produce very differently: yours matters more than the regional average.
Auvergne-Rhône-Alpes is the region where solar output varies most from one commune to the next: from 887 to 1,540 kWh per kWp a year, by our calculation on the European Commission’s PVGIS data, for a regional median of 1,248 kWh, above the national median of 1,185. The south of the region, with Drôme (1,385 kWh median) and Ardèche (1,357), is already close to Provence. Deep Alpine valleys, by contrast, lose hours of sun behind the peaks, and some communes in Savoie fall below Lille’s level. In Lyon, 3 kWp for a household using 4,500 kWh a year pays back in 16.9 years; in Valence, in 16.5 years. In the mountain départements, do not rely on the average: the calculator starts from your commune’s own value, calculated with the real terrain horizon.
Pays for itself in · 3 kWp in Lyon
16.9 years
Net result over 20 years: +€1,114
| Output per year | 3,843 kWh |
| Used on site (44 %) | 1,693 kWh |
| Bill saving, year 1 | €339 |
| Surplus sold (2,150 kWh) | €24 |
| Standing-charge surcharge (export) | −€12 |
| Gain in year 1 | €351 |
| Share of your bill covered | 38 % |
| Price used (estimate) | €6,000 |
| Best-value size (estimated prices) | 2 kWc |
Month-by-month output in Lyon (3 kWp)
December: 153 kWh; July: 446 kWh. PVGIS average 2005-2023.
Checked by Radif Partners · Editorial policy · Method and sources
The twelve départements
| Département | Median kWh/kWp | Communes: from… to… | 3 kWp pays back in |
|---|---|---|---|
| Drôme (26) | 1,385 | 1,133 – 1,540 | 16.5 years |
| Ardèche (07) | 1,357 | 1,210 – 1,488 | 16.6 years |
| Isère (38) | 1,283 | 1,050 – 1,437 | 16.9 years |
| Savoie (73) | 1,279 | 887 – 1,431 | 17.0 years |
| Cantal (15) | 1,257 | 1,097 – 1,312 | 17.1 years |
| Rhône (69) | 1,248 | 1,152 – 1,304 | 17.1 years |
| Haute-Savoie (74) | 1,248 | 1,064 – 1,349 | 17.1 years |
| Ain (01) | 1,237 | 1,086 – 1,289 | 17.2 years |
| Loire (42) | 1,232 | 1,150 – 1,287 | 17.2 years |
| Haute-Loire (43) | 1,221 | 1,094 – 1,283 | 17.3 years |
| Puy-de-Dôme (63) | 1,218 | 1,092 – 1,267 | 17.3 years |
| Allier (03) | 1,207 | 1,164 – 1,238 | 17.4 years |
The “from… to…” columns tell more here than anywhere in France. In Isère, communes range from 1,050 to 1,437 kWh per kWp; Grenoble, in its basin, reaches 1,306. In the Drôme, the range runs from 1,133 to 1,540, between mountain communes and those in the south of the département. Yet payback in the table, calculated at the median, varies little between départements (from 16.5 years to 17.4 years): household usage matters more than a few dozen kWh per kWp.
Terrain and horizon: what the average hides
PVGIS calculates for each point the horizon formed by the surrounding terrain: a north-facing slope or a valley floor loses the low winter sun well before sunset. That is why two neighbouring villages can produce very differently. Nearby shade, such as a forest or barn, comes on top and is not counted: have it checked on site.
How much do you lose with your roof’s facing?
Output vs due south at 35°
81 %
| Loss (or gain) | −19 % |
| For 3 kWp in Paris | 2,776 kWh |
Factors calculated with PVGIS 5.3 for seven reference cities.
One region, two winter climates
The region mixes areas where heating weighs very heavily in winter, at altitude, with a milder Rhône valley. The more electric heating dominates usage, the less solar output matches needs: set the calculator to the “electric heating” profile if that is your case, and compare the sizes it suggests.