Peak Sun Hours in Fortaleza, Ceará, Brazil
- Solar zone
- Zone 4 (excellent)
- Best month
- October (6.7)
- Worst month
- April (4.8)
- Climate
- Equatorial · 27.2°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 5.63 | 7.14 | 3.76 | 2.55 | 27.5 | 78 |
| Feb | 5.42 | 7.25 | 3.28 | 2.53 | 27.4 | 81 |
| Mar | 5.25 | 7.24 | 3.16 | 2.47 | 27.3 | 83 |
| Apr | 4.84 | 6.88 | 2.85 | 2.35 | 27.2 | 84 |
| May | 5.12 | 6.41 | 4.06 | 2.09 | 27.2 | 83 |
| Jun | 5.13 | 6.15 | 4.50 | 1.91 | 26.7 | 81 |
| Jul | 5.51 | 6.31 | 5.15 | 1.85 | 26.4 | 78 |
| Aug | 6.24 | 6.77 | 5.90 | 1.90 | 26.6 | 74 |
| Sep | 6.66 | 7.17 | 6.00 | 2.06 | 27.0 | 72 |
| Oct | 6.69 | 7.38 | 5.83 | 2.26 | 27.4 | 72 |
| Nov | 6.49 | 7.30 | 5.67 | 2.37 | 27.7 | 72 |
| Dec | 6.11 | 7.10 | 4.93 | 2.43 | 27.9 | 74 |
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 4.84 kWh/m²/day, 0.77 system efficiency.
About solar in Fortaleza
Fortaleza, Brazil sits near the equator, where day length is stable year-round and the sun passes close to overhead. Its annual peak sun hours average 5.76 kWh/m²/day, a excellent solar resource by global standards.
The strongest month in Fortaleza is October (spring) at 6.69 kWh/m²/day, and the weakest is April (autumn) at 4.84 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the April value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Fortaleza'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 Fortaleza?
- Fortaleza averages 5.76 peak sun hours per day annually, ranging from 4.84 in April to 6.69 in October.
- How many solar panels do I need in Fortaleza?
- Panel count depends on your daily load. At Fortaleza's annual average of 5.76 kWh/m²/day, a 5 kWh/day load needs roughly 3 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Fortaleza?
- Sizing against Fortaleza's worst month (April, 4.84 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 Fortaleza's solar resource compare globally?
- Fortaleza sits in solar zone 4 out of 5 (where 5 is strongest) at 5.76 kWh/m²/day — excellent by global standards. For reference, top-tier desert sites average ~6.5 and high-latitude cities around 2.5 kWh/m²/day.
- Why doesn't solar output vary much by month in Fortaleza?
- Near the equator, day length is nearly constant year-round and the sun stays close to overhead. In Fortaleza, monthly PSH ranges just from 4.84 to 6.69 kWh/m²/day — variance is driven by wet-season cloud cover, not day length.
- What tilt angle works best for panels in Fortaleza?
- At latitude 4°, panels in Fortaleza work best at a low tilt (roughly 4°) or horizontal. Tracking mounts add little benefit this close to the equator.
- How does the wet season affect solar output in Fortaleza?
- Equatorial wet seasons reduce output through cloud cover, not day length. Fortaleza's worst month (April) still delivers 4.84 kWh/m²/day — design against this value for reliable year-round off-grid use.