Peak Sun Hours in Vigo, Galicia, Spain
- Solar zone
- Zone 3 (good)
- Best month
- July (6.7)
- Worst month
- December (1.4)
- Climate
- Temperate · 14.4°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 1.58 | 2.53 | 2.37 | 0.80 | 9.2 | 88 |
| Feb | 2.55 | 3.72 | 3.31 | 1.17 | 9.3 | 84 |
| Mar | 3.66 | 5.31 | 3.85 | 1.64 | 11.0 | 82 |
| Apr | 4.97 | 6.90 | 4.56 | 2.14 | 12.7 | 81 |
| May | 5.96 | 8.00 | 5.26 | 2.43 | 15.1 | 79 |
| Jun | 6.53 | 8.42 | 5.92 | 2.47 | 18.1 | 74 |
| Jul | 6.73 | 8.15 | 6.58 | 2.28 | 20.3 | 68 |
| Aug | 5.98 | 7.19 | 6.26 | 2.00 | 20.6 | 67 |
| Sep | 4.71 | 5.74 | 5.45 | 1.66 | 19.1 | 69 |
| Oct | 2.93 | 4.12 | 3.62 | 1.27 | 15.9 | 79 |
| Nov | 1.84 | 2.81 | 2.68 | 0.89 | 11.8 | 85 |
| Dec | 1.43 | 2.20 | 2.44 | 0.70 | 9.7 | 87 |
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 1.43 kWh/m²/day, 0.77 system efficiency.
About solar in Vigo
Vigo, Spain has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 4.07 kWh/m²/day, a good solar resource by global standards.
The strongest month in Vigo is July (summer) at 6.73 kWh/m²/day, and the weakest is December (winter) at 1.43 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.
Vigo's solar conditions are well within the range where off-grid PV is a straightforward engineering exercise with standard-sized arrays and lithium batteries.
FAQ
- What are the peak sun hours in Vigo?
- Vigo averages 4.07 peak sun hours per day annually, ranging from 1.43 in December to 6.73 in July.
- How many solar panels do I need in Vigo?
- Panel count depends on your daily load. At Vigo's annual average of 4.07 kWh/m²/day, a 5 kWh/day load needs roughly 4 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Vigo?
- Sizing against Vigo's worst month (December, 1.43 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 Vigo's solar resource compare globally?
- Vigo sits in solar zone 3 out of 5 (where 5 is strongest) at 4.07 kWh/m²/day — good 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 Vigo?
- Vigo's worst month (December) delivers 1.43 kWh/m²/day — about 21% of the summer peak of 6.73. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Vigo's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Vigo's 4.07 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Vigo?
- At Vigo's latitude (42°), a fixed tilt near 42° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.