Solar panels in Grand Est (Alsace, Lorraine, Champagne)
The calculator opens on Strasbourg. The continental climate concentrates output in summer more than elsewhere: here is what that changes.
In Grand Est, the median commune produces 1,129 kWh per kWp a year, slightly below the national median of 1,185, by our calculation on the European Commission’s PVGIS data. Southern Alsace is best placed: Haut-Rhin reaches a median of 1,177 kWh, and Colmar 1,179. The Ardennes and the Vosges summits come last, with communes below 1,000 kWh. The region’s defining feature is its continental climate: in Strasbourg, June output is about 3.7 times December’s, one of the widest gaps in France. Panels therefore produce mostly when the house heats least. For a household using 4,500 kWh a year without electric heating, 3 kWp in Strasbourg uses 46 % of its output on site and pays back in 18.5 years. Households with summer usage, a pool or a hot-water tank timed for daytime, gain most.
Pays for itself in · 3 kWp in Strasbourg
18.5 years
Net result over 20 years: +€482
| Output per year | 3,414 kWh |
| Used on site (46 %) | 1,554 kWh |
| Bill saving, year 1 | €311 |
| Surplus sold (1,860 kWh) | €20 |
| Standing-charge surcharge (export) | −€12 |
| Gain in year 1 | €320 |
| Share of your bill covered | 35 % |
| Price used (estimate) | €6,000 |
| Best-value size (estimated prices) | 1.5 kWc |
Month-by-month output in Strasbourg (3 kWp)
December: 109 kWh; July: 408 kWh. PVGIS average 2005-2023.
Checked by Radif Partners · Editorial policy · Method and sources
The ten départements
| Département | Median kWh/kWp | Communes: from… to… | 3 kWp pays back in |
|---|---|---|---|
| Haut-Rhin (68) | 1,177 | 961 – 1,218 | 18.4 years |
| Aube (10) | 1,168 | 1,124 – 1,198 | 17.9 years |
| Marne (51) | 1,158 | 1,099 – 1,194 | 17.9 years |
| Bas-Rhin (67) | 1,133 | 1,009 – 1,168 | 18.6 years |
| Haute-Marne (52) | 1,132 | 1,108 – 1,178 | 18.1 years |
| Vosges (88) | 1,131 | 1,000 – 1,155 | 18.6 years |
| Meurthe-et-Moselle (54) | 1,122 | 1,054 – 1,142 | 18.7 years |
| Meuse (55) | 1,112 | 1,057 – 1,126 | 18.7 years |
| Moselle (57) | 1,109 | 998 – 1,146 | 18.8 years |
| Ardennes (08) | 1,089 | 938 – 1,159 | 18.8 years |
Champagne and southern Alsace are the two most productive areas; the uplands, the Ardennes in the north and the Vosges in the centre, the least, with communes going down to 938 kWh per kWp. Between these extremes, the Lorraine plain stays close to Paris.
Strong summer, weak winter: how to allow for it
A household heated by electricity uses a lot when panels produce little. At 9,000 kWh a year with a heating profile, 3 kWp in Strasbourg still pays back in 12.5 years, because base load absorbs summer output. Enlarging the system to cover winter does not work, though: summer surplus grows far faster than December output.
How much of your output will you use yourself?
Self-consumption rate
46 %
| Used on site | 1,620 kWh |
| Exported to the grid | 1,909 kWh |
| Share of the bill covered | 36 % |
| Saving in year 1 | €324 |
Median French output (1,185 kWh/kWp), roof at 30° due south, hour-by-hour calculation.
Cross-border workers and French rules
The rules are French ones, whatever country you work in: the feed-in tariff of the order of 1 June 2026 and reduced VAT under conditions. Offers from Germany or Switzerland must be connected and declared under the French procedure.