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Peak Sun Hours in Gasteiz / Vitoria, Basque Country, Spain

4.0
kWh/m²/day (annual avg)
Solar zone
Zone 2 (moderate)
Best month
July (6.7)
Worst month
December (1.5)
Climate
Temperate · 11.8°C

Monthly solar breakdown

J: 1.64 kWh/m²/day F: 2.46 kWh/m²/day M: 3.67 kWh/m²/day A: 4.71 kWh/m²/day M: 5.63 kWh/m²/day J: 6.4 kWh/m²/day J: 6.71 kWh/m²/day A: 5.83 kWh/m²/day S: 4.52 kWh/m²/day O: 3 kWh/m²/day N: 1.83 kWh/m²/day D: 1.48 kWh/m²/day J F M A M J J A S O N D 8 0
Month GHI Clear-sky DNI DHI Temp °C Humid %
Jan 1.64 2.63 2.66 0.81 5.3 88
Feb 2.46 3.80 3.26 1.15 5.5 84
Mar 3.67 5.38 3.75 1.73 8.0 81
Apr 4.71 6.90 3.89 2.30 10.3 80
May 5.63 7.98 4.43 2.62 13.3 79
Jun 6.40 8.33 5.31 2.65 16.9 78
Jul 6.71 8.08 6.27 2.37 18.7 76
Aug 5.83 7.13 5.67 2.15 19.1 73
Sep 4.52 5.73 4.88 1.78 16.9 74
Oct 3.00 4.18 3.79 1.32 13.5 77
Nov 1.83 2.88 2.80 0.90 8.6 85
Dec 1.48 2.29 2.68 0.71 5.8 87

GHI, Clear-sky, DNI, DHI in kWh/m²/day. Data: NASA POWER climatology (long-term monthly averages).

Off-grid calculator

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Sizing

Daily load
0.00 kWh
Panel wattage
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Panel count (400W modules)
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Battery bank
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Sizing against worst-month PSH of 1.48 kWh/m²/day, 0.77 system efficiency.

About solar in Gasteiz / Vitoria

Gasteiz / Vitoria, Spain has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 3.99 kWh/m²/day, a moderate solar resource by global standards.

The strongest month in Gasteiz / Vitoria is July (summer) at 6.71 kWh/m²/day, and the weakest is December (winter) at 1.48 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, Gasteiz / Vitoria installations typically oversize panels or combine solar with another source (grid, generator, hydro) for reliability.

FAQ

What are the peak sun hours in Gasteiz / Vitoria?
Gasteiz / Vitoria averages 3.99 peak sun hours per day annually, ranging from 1.48 in December to 6.71 in July.
How many solar panels do I need in Gasteiz / Vitoria?
Panel count depends on your daily load. At Gasteiz / Vitoria's annual average of 3.99 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 Gasteiz / Vitoria?
Sizing against Gasteiz / Vitoria's worst month (December, 1.48 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 Gasteiz / Vitoria's solar resource compare globally?
Gasteiz / Vitoria sits in solar zone 2 out of 5 (where 5 is strongest) at 3.99 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 Gasteiz / Vitoria?
Gasteiz / Vitoria's worst month (December) delivers 1.48 kWh/m²/day — about 22% of the summer peak of 6.71. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
Do cloudy days significantly affect Gasteiz / Vitoria's solar?
Partly. Diffuse light still produces 10–25% of clear-sky output. Gasteiz / Vitoria's 3.99 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
What panel tilt works best in Gasteiz / Vitoria?
At Gasteiz / Vitoria's latitude (43°), a fixed tilt near 43° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.