Solar panels in Centre-Val de Loire
The calculator opens on Tours. In this region sunshine rises from north to south: from the Beauce to the Berry, the figures département by département.
Centre-Val de Loire produces a median of 1,195 kWh per kWp a year, slightly above the national median of 1,185, by our calculation on the European Commission’s PVGIS data. The region forms a steady gradient: the southern départements, led by Indre with 1,205 kWh, are ahead of the northern ones, where Loiret comes last at 1,175. The two largest cities show the gap. Tours, at 1,197 kWh per kWp, produces about 3 % more than Orléans (1,158). For a household using 4,500 kWh a year with 3 kWp, that means a payback of 17.7 years in Tours and 17.9 years in Orléans. Here the difference between two projects depends less on the city than on the roof itself and on how much of the output the house uses during the day. Many houses also have a plot of land, which opens the way to ground-mounted panels.
Pays for itself in · 3 kWp in Tours
17.7 years
Net result over 20 years: +€778
| Output per year | 3,565 kWh |
| Used on site (46 %) | 1,623 kWh |
| Bill saving, year 1 | €325 |
| Surplus sold (1,942 kWh) | €21 |
| Standing-charge surcharge (export) | −€12 |
| Gain in year 1 | €334 |
| Share of your bill covered | 36 % |
| Price used (estimate) | €6,000 |
| Best-value size (estimated prices) | 2 kWc |
Month-by-month output in Tours (3 kWp)
December: 133 kWh; July: 423 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 |
|---|---|---|---|
| Indre (36) | 1,205 | 1,186 – 1,228 | 17.7 years |
| Indre-et-Loire (37) | 1,203 | 1,187 – 1,227 | 17.7 years |
| Cher (18) | 1,202 | 1,145 – 1,221 | 17.7 years |
| Loir-et-Cher (41) | 1,194 | 1,142 – 1,211 | 17.7 years |
| Eure-et-Loir (28) | 1,188 | 1,130 – 1,204 | 17.8 years |
| Loiret (45) | 1,175 | 1,144 – 1,198 | 17.8 years |
From one commune to the next, output ranges from 1,130 to 1,228 kWh per kWp, a modest spread. The least productive communes are in the north, in Eure-et-Loir near Île-de-France and in the Sologne forests; the most productive in the south of the Cher and Touraine, and in the Champagne berrichonne at the heart of the Indre.
Size the system before comparing quotes
With surplus bought at 1.1 c€/kWh, the useful size depends mainly on daytime usage. For an 8,000 kWh household in Tours, the best 20-year size is 3 kWp; in Orléans, 3 kWp. The mini-calculator below gives the expected output in your département.
How many panels for your home?
Number of panels
5
| Best-value system size | 2 kWc |
| Output per year | 2,388 kWh |
| Net over 20 years | +€1,165 |
Best 20-year net gain among 13 sizes, at estimated prices. A module’s power is on its datasheet.
A plot, a barn, a roof
A house with outbuildings often offers a choice of several roof slopes. Pick the least shaded one closest to south, then compare with a self-install kit if the budget is tight. Any system on a roof goes through a prior declaration.