Solar panels in Provence-Alpes-Côte d’Azur
The calculator opens on Marseille. This region produces the most in France: the question is not whether panels work, but which size to avoid.
Provence-Alpes-Côte d’Azur is the sunniest region of mainland France for photovoltaics: the median commune produces 1,494 kWh per kWp a year, 26 % more than the national median, by our calculation on the European Commission’s PVGIS data. Bouches-du-Rhône leads with 1,558 kWh. In Marseille, 3 kWp for a household using 4,500 kWh a year produces 4,669 kWh and pays back in 14.9 years, against 18.0 years in Paris. But that sunshine has a downside now that surplus earns only 1.1 c€/kWh: a system quickly produces more than the house uses. The same Marseille household uses only 41 % of its output, and the size that earns it most over twenty years is just 2 kWp. In the south-east, sizing small is the rule that best protects your return.
Pays for itself in · 3 kWp in Marseille
14.9 years
Net result over 20 years: +€2,098
| Output per year | 4,669 kWh |
| Used on site (41 %) | 1,897 kWh |
| Bill saving, year 1 | €380 |
| Surplus sold (2,772 kWh) | €30 |
| Standing-charge surcharge (export) | −€12 |
| Gain in year 1 | €398 |
| Share of your bill covered | 42 % |
| Price used (estimate) | €6,000 |
| Best-value size (estimated prices) | 2 kWc |
Month-by-month output in Marseille (3 kWp)
December: 251 kWh; July: 515 kWh. PVGIS average 2005-2023.
Checked by Radif Partners · Editorial policy · Method and sources
The six départements
| Département | Median kWh/kWp | Communes: from… to… | 3 kWp pays back in |
|---|---|---|---|
| Bouches-du-Rhône (13) | 1,558 | 1,477 – 1,583 | 14.9 years |
| Vaucluse (84) | 1,538 | 1,407 – 1,589 | 15.0 years |
| Var (83) | 1,517 | 1,482 – 1,565 | 15.1 years |
| Alpes-de-Haute-Provence (04) | 1,468 | 1,262 – 1,562 | 15.2 years |
| Alpes-Maritimes (06) | 1,436 | 1,132 – 1,521 | 15.2 years |
| Hautes-Alpes (05) | 1,404 | 1,143 – 1,534 | 15.3 years |
Along the coast and in the Rhône valley, output is very even. The gap widens in the mountains: yet the region’s least productive commune, at 1,132 kWh per kWp, is still on a par with Paris. In Nice, 3 kWp produces 4,410 kWh, slightly less than in Marseille (4,669).
The large-system trap
One kWp in Marseille produces as much as about 1.45 kWp in Lille. A 6 kWp offer, common elsewhere, therefore doubles output that already exceeds many households’ usage. For the reference household, surplus reaches 2,772 kWh a year with 3 kWp; it earns €30 in year one, from which the €12 standing-charge surcharge (incl. VAT) due when you export must be deducted. Whether to sell surplus, and which size to choose: the calculator compares both.
How many panels for your home?
Number of panels
5
| Best-value system size | 2 kWc |
| Output per year | 3,091 kWh |
| Net over 20 years | +€2,523 |
Best 20-year net gain among 13 sizes, at estimated prices. A module’s power is on its datasheet.
Heat and efficiency
Modules lose a little efficiency as they heat up, which the 14% losses used in PVGIS and its radiation database account for on average. Mounting that lets air flow under the modules limits the effect; ask the installer about it. Output nonetheless remains the highest in France.