Peak Sun Hours in Porto Velho, Rondônia, Brazil
- Solar zone
- Zone 3 (good)
- Best month
- July (5.3)
- Worst month
- December (4.5)
- Climate
- Equatorial · 26.5°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 4.59 | 7.19 | 1.79 | 2.57 | 25.6 | 91 |
| Feb | 4.48 | 7.17 | 1.68 | 2.50 | 25.6 | 91 |
| Mar | 4.53 | 6.90 | 1.86 | 2.47 | 25.6 | 91 |
| Apr | 4.56 | 6.45 | 2.53 | 2.26 | 25.6 | 91 |
| May | 4.46 | 5.91 | 3.40 | 1.91 | 25.3 | 90 |
| Jun | 4.88 | 5.68 | 4.97 | 1.56 | 25.4 | 86 |
| Jul | 5.27 | 5.85 | 5.58 | 1.48 | 26.4 | 75 |
| Aug | 5.17 | 5.86 | 4.09 | 1.97 | 28.3 | 65 |
| Sep | 5.00 | 6.15 | 3.02 | 2.23 | 29.0 | 68 |
| Oct | 5.07 | 6.90 | 2.55 | 2.51 | 28.2 | 75 |
| Nov | 4.77 | 7.03 | 2.04 | 2.56 | 27.2 | 82 |
| Dec | 4.45 | 7.02 | 1.75 | 2.49 | 26.1 | 89 |
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 4.45 kWh/m²/day, 0.77 system efficiency.
About solar in Porto Velho
Porto Velho, 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 4.77 kWh/m²/day, a good solar resource by global standards.
The strongest month in Porto Velho is July (winter) at 5.27 kWh/m²/day, and the weakest is December (summer) at 4.45 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.
Porto Velho'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 Porto Velho?
- Porto Velho averages 4.77 peak sun hours per day annually, ranging from 4.45 in December to 5.27 in July.
- How many solar panels do I need in Porto Velho?
- Panel count depends on your daily load. At Porto Velho's annual average of 4.77 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 Porto Velho?
- Sizing against Porto Velho's worst month (December, 4.45 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 Porto Velho's solar resource compare globally?
- Porto Velho sits in solar zone 3 out of 5 (where 5 is strongest) at 4.77 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.
- Why doesn't solar output vary much by month in Porto Velho?
- Near the equator, day length is nearly constant year-round and the sun stays close to overhead. In Porto Velho, monthly PSH ranges just from 4.45 to 5.27 kWh/m²/day — variance is driven by wet-season cloud cover, not day length.
- What tilt angle works best for panels in Porto Velho?
- At latitude 9°, panels in Porto Velho work best at a low tilt (roughly 9°) or horizontal. Tracking mounts add little benefit this close to the equator.
- How does the wet season affect solar output in Porto Velho?
- Equatorial wet seasons reduce output through cloud cover, not day length. Porto Velho's worst month (December) still delivers 4.45 kWh/m²/day — design against this value for reliable year-round off-grid use.