Peak Sun Hours in Teresina, Piauí, Brazil
- Solar zone
- Zone 4 (excellent)
- Best month
- September (6.8)
- Worst month
- April (5.3)
- Climate
- Equatorial · 28.2°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 5.38 | 7.31 | 3.27 | 2.48 | 27.4 | 74 |
| Feb | 5.44 | 7.38 | 3.05 | 2.57 | 26.3 | 83 |
| Mar | 5.50 | 7.26 | 3.23 | 2.53 | 26.1 | 86 |
| Apr | 5.33 | 6.82 | 3.66 | 2.29 | 25.9 | 87 |
| May | 5.41 | 6.32 | 4.81 | 1.92 | 26.3 | 81 |
| Jun | 5.49 | 6.09 | 5.81 | 1.52 | 26.9 | 68 |
| Jul | 5.81 | 6.28 | 6.40 | 1.37 | 27.8 | 56 |
| Aug | 6.45 | 6.81 | 6.97 | 1.41 | 29.2 | 47 |
| Sep | 6.75 | 7.24 | 6.61 | 1.69 | 30.7 | 44 |
| Oct | 6.60 | 7.40 | 5.82 | 2.00 | 31.3 | 46 |
| Nov | 6.12 | 7.32 | 4.89 | 2.23 | 30.8 | 51 |
| Dec | 5.67 | 7.21 | 4.00 | 2.40 | 29.6 | 59 |
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 5.33 kWh/m²/day, 0.77 system efficiency.
About solar in Teresina
Teresina, 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 5.83 kWh/m²/day, a excellent solar resource by global standards.
The strongest month in Teresina is September (spring) at 6.75 kWh/m²/day, and the weakest is April (autumn) at 5.33 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.
Teresina'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 Teresina?
- Teresina averages 5.83 peak sun hours per day annually, ranging from 5.33 in April to 6.75 in September.
- How many solar panels do I need in Teresina?
- Panel count depends on your daily load. At Teresina's annual average of 5.83 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 Teresina?
- Sizing against Teresina's worst month (April, 5.33 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 Teresina's solar resource compare globally?
- Teresina sits in solar zone 4 out of 5 (where 5 is strongest) at 5.83 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 Teresina?
- Near the equator, day length is nearly constant year-round and the sun stays close to overhead. In Teresina, monthly PSH ranges just from 5.33 to 6.75 kWh/m²/day — variance is driven by wet-season cloud cover, not day length.
- What tilt angle works best for panels in Teresina?
- At latitude 5°, panels in Teresina work best at a low tilt (roughly 5°) or horizontal. Tracking mounts add little benefit this close to the equator.
- How does the wet season affect solar output in Teresina?
- Equatorial wet seasons reduce output through cloud cover, not day length. Teresina's worst month (April) still delivers 5.33 kWh/m²/day — design against this value for reliable year-round off-grid use.