Solar panels in Normandy
The calculator opens on Le Havre. In Normandy it is the coast that gets most sun, not inland: the figures city by city.
Normandy produces a median of 1,118 kWh per kWp a year, slightly below the national median of 1,185, by our calculation on the European Commission’s PVGIS data. Its five départements are very close, from 1,100 kWh for Seine-Maritime to 1,128 for Eure. The region’s solar geography is surprising: coastal communes get more sun than those in the Seine valley. Caen, at 1,144 kWh per kWp, even produces slightly more than Paris (1,140), while Rouen, further inland, stops at 1,092. For a 4,500 kWh household with 3 kWp, payback is 18.0 years in Caen and 18.3 years in Rouen. In a region rich in old houses and protected areas, the other question is often planning permission, before output even comes into it.
Pays for itself in · 3 kWp in Le Havre
18.1 years
Net result over 20 years: +€645
| Output per year | 3,368 kWh |
| Used on site (48 %) | 1,601 kWh |
| Bill saving, year 1 | €320 |
| Surplus sold (1,767 kWh) | €19 |
| Standing-charge surcharge (export) | −€12 |
| Gain in year 1 | €328 |
| Share of your bill covered | 36 % |
| Price used (estimate) | €6,000 |
| Best-value size (estimated prices) | 2 kWc |
Month-by-month output in Le Havre (3 kWp)
December: 126 kWh; July: 400 kWh. PVGIS average 2005-2023.
Checked by Radif Partners · Editorial policy · Method and sources
The five départements
| Département | Median kWh/kWp | Communes: from… to… | 3 kWp pays back in |
|---|---|---|---|
| Eure (27) | 1,128 | 1,090 – 1,168 | 18.1 years |
| Manche (50) | 1,125 | 1,084 – 1,178 | 18.3 years |
| Orne (61) | 1,124 | 1,097 – 1,157 | 18.1 years |
| Calvados (14) | 1,119 | 1,081 – 1,149 | 18.2 years |
| Seine-Maritime (76) | 1,100 | 1,064 – 1,144 | 18.3 years |
The regional range is one of the narrowest in France, from 1,064 to 1,178 kWh per kWp. In each département, coastal communes sit at the top of the range: the pattern holds along the whole Channel coast. Seine-Maritime comes last, with Rouen the least productive of the region’s large cities.
An average system, well sized
With output close to the northern French average, the sizing rule is the same as in Paris: aim at daytime usage. For an 8,000 kWh household in Rouen, the best 20-year size is 3.5 kWp; in Le Havre, 3 kWp. Beyond that, extra surplus earns 1.1 c€/kWh.
Which formalities for your system?
Planning
Prior declaration
| Enedis connection | Request + feed-in contract |
| Sale income taxable | No (3 kWp or less) |
The file goes to the town hall; it is processed within one month, two in protected areas.
Before fitting
Start with the prior declaration, especially in old town centres and listed villages. Then compare at least two quotes, checking the roof’s actual facing (facing factor): a main slope facing east or west cuts output but raises the share used on site.