Peak Sun Hours in Porto Alegre, Rio Grande do Sul, Brazil
- Solar zone
- Zone 3 (good)
- Best month
- December (6.7)
- Worst month
- June (2.4)
- Climate
- Temperate · 19.3°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 6.53 | 8.56 | 5.35 | 2.47 | 24.5 | 78 |
| Feb | 5.96 | 7.79 | 5.19 | 2.23 | 24.6 | 77 |
| Mar | 5.05 | 6.60 | 4.84 | 1.90 | 23.3 | 78 |
| Apr | 3.93 | 5.20 | 4.37 | 1.45 | 20.5 | 80 |
| May | 2.90 | 4.04 | 3.57 | 1.21 | 16.6 | 84 |
| Jun | 2.42 | 3.45 | 3.16 | 1.05 | 14.5 | 86 |
| Jul | 2.64 | 3.69 | 3.51 | 1.03 | 13.6 | 86 |
| Aug | 3.31 | 4.58 | 3.75 | 1.28 | 15.1 | 85 |
| Sep | 3.99 | 5.86 | 3.76 | 1.60 | 16.6 | 84 |
| Oct | 5.04 | 7.32 | 4.23 | 2.06 | 19.1 | 83 |
| Nov | 6.30 | 8.44 | 5.48 | 2.25 | 20.8 | 80 |
| Dec | 6.73 | 8.83 | 5.75 | 2.41 | 23.0 | 79 |
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 2.42 kWh/m²/day, 0.77 system efficiency.
About solar in Porto Alegre
Porto Alegre, Brazil has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 4.57 kWh/m²/day, a good solar resource by global standards.
The strongest month in Porto Alegre is December (summer) at 6.73 kWh/m²/day, and the weakest is June (winter) at 2.42 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the June value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Porto Alegre'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 Alegre?
- Porto Alegre averages 4.57 peak sun hours per day annually, ranging from 2.42 in June to 6.73 in December.
- How many solar panels do I need in Porto Alegre?
- Panel count depends on your daily load. At Porto Alegre's annual average of 4.57 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 Alegre?
- Sizing against Porto Alegre's worst month (June, 2.42 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 Alegre's solar resource compare globally?
- Porto Alegre sits in solar zone 3 out of 5 (where 5 is strongest) at 4.57 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 Porto Alegre?
- Porto Alegre's worst month (June) delivers 2.42 kWh/m²/day — about 36% 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 Porto Alegre's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Porto Alegre's 4.57 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Porto Alegre?
- At Porto Alegre's latitude (30°), a fixed tilt near 30° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.