Peak Sun Hours in Clermont-Ferrand, Rhône-Alpes, France
- Solar zone
- Zone 2 (moderate)
- Best month
- July (6.1)
- Worst month
- December (1.1)
- Climate
- Temperate · 10.4°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 1.34 | 2.24 | 2.22 | 0.72 | 1.9 | 91 |
| Feb | 2.23 | 3.43 | 3.06 | 1.09 | 2.3 | 87 |
| Mar | 3.41 | 5.03 | 3.65 | 1.60 | 5.8 | 82 |
| Apr | 4.46 | 6.66 | 3.93 | 2.12 | 9.3 | 78 |
| May | 5.23 | 7.85 | 4.04 | 2.56 | 13.1 | 77 |
| Jun | 6.10 | 8.30 | 4.94 | 2.73 | 17.7 | 71 |
| Jul | 6.12 | 7.99 | 5.38 | 2.51 | 20.0 | 64 |
| Aug | 5.29 | 6.94 | 5.04 | 2.18 | 19.7 | 63 |
| Sep | 4.09 | 5.47 | 4.53 | 1.71 | 15.5 | 69 |
| Oct | 2.62 | 3.79 | 3.38 | 1.23 | 11.4 | 79 |
| Nov | 1.54 | 2.48 | 2.43 | 0.78 | 6.1 | 88 |
| Dec | 1.15 | 1.89 | 2.26 | 0.58 | 2.6 | 90 |
GHI, Clear-sky, DNI, DHI in kWh/m²/day. Data: NASA POWER climatology (long-term monthly averages).
Off-grid calculator
Add appliances
- Add an appliance to size a system.
Sizing
- Daily load
- 0.00 kWh
- Panel wattage
- 0 W
- Panel count (400W modules)
- 0
- Battery bank
- 0.0 kWh
Sizing against worst-month PSH of 1.15 kWh/m²/day, 0.77 system efficiency.
About solar in Clermont-Ferrand
Clermont-Ferrand, France has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 3.63 kWh/m²/day, a moderate solar resource by global standards.
The strongest month in Clermont-Ferrand is July (summer) at 6.12 kWh/m²/day, and the weakest is December (winter) at 1.15 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the December value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Given the moderate resource, Clermont-Ferrand installations typically oversize panels or combine solar with another source (grid, generator, hydro) for reliability.
FAQ
- What are the peak sun hours in Clermont-Ferrand?
- Clermont-Ferrand averages 3.63 peak sun hours per day annually, ranging from 1.15 in December to 6.12 in July.
- How many solar panels do I need in Clermont-Ferrand?
- Panel count depends on your daily load. At Clermont-Ferrand's annual average of 3.63 kWh/m²/day, a 5 kWh/day load needs roughly 5 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Clermont-Ferrand?
- Sizing against Clermont-Ferrand's worst month (December, 1.15 kWh/m²/day) with 2 days of autonomy at 80% depth of discharge, a 5 kWh/day load needs about a 12.5 kWh battery bank.
- How does Clermont-Ferrand's solar resource compare globally?
- Clermont-Ferrand sits in solar zone 2 out of 5 (where 5 is strongest) at 3.63 kWh/m²/day — moderate by global standards. For reference, top-tier desert sites average ~6.5 and high-latitude cities around 2.5 kWh/m²/day.
- How much does winter reduce solar output in Clermont-Ferrand?
- Clermont-Ferrand's worst month (December) delivers 1.15 kWh/m²/day — about 19% of the summer peak of 6.12. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Clermont-Ferrand's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Clermont-Ferrand's 3.63 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Clermont-Ferrand?
- At Clermont-Ferrand's latitude (46°), a fixed tilt near 46° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.