Peak Sun Hours in Rạch Giá, An Giang, Vietnam
- Solar zone
- Zone 4 (excellent)
- Best month
- April (5.9)
- Worst month
- December (4.8)
- Climate
- Tropical · 27.8°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 4.96 | 5.80 | 4.01 | 2.22 | 26.6 | 74 |
| Feb | 5.47 | 6.31 | 3.77 | 2.57 | 28.2 | 66 |
| Mar | 5.74 | 6.69 | 3.68 | 2.67 | 29.7 | 64 |
| Apr | 5.86 | 6.89 | 3.92 | 2.55 | 30.4 | 66 |
| May | 5.36 | 6.96 | 3.25 | 2.55 | 29.4 | 77 |
| Jun | 5.02 | 6.89 | 2.70 | 2.58 | 28.1 | 84 |
| Jul | 4.83 | 6.89 | 2.29 | 2.61 | 27.5 | 86 |
| Aug | 4.87 | 6.94 | 2.30 | 2.59 | 27.3 | 87 |
| Sep | 4.82 | 6.78 | 2.29 | 2.58 | 27.1 | 87 |
| Oct | 4.80 | 6.40 | 2.79 | 2.39 | 27.0 | 87 |
| Nov | 4.81 | 5.97 | 3.54 | 2.23 | 26.7 | 85 |
| Dec | 4.76 | 5.68 | 4.01 | 2.14 | 26.2 | 80 |
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 4.76 kWh/m²/day, 0.77 system efficiency.
About solar in Rạch Giá
Rạch Giá, Vietnam has a warm, tropical climate with a distinct wet and dry season. Its annual peak sun hours average 5.11 kWh/m²/day, a excellent solar resource by global standards.
The strongest month in Rạch Giá is April (spring) at 5.86 kWh/m²/day, and the weakest is December (winter) at 4.76 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.
Rạch Giá'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 Rạch Giá?
- Rạch Giá averages 5.11 peak sun hours per day annually, ranging from 4.76 in December to 5.86 in April.
- How many solar panels do I need in Rạch Giá?
- Panel count depends on your daily load. At Rạch Giá's annual average of 5.11 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 Rạch Giá?
- Sizing against Rạch Giá's worst month (December, 4.76 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 Rạch Giá's solar resource compare globally?
- Rạch Giá sits in solar zone 4 out of 5 (where 5 is strongest) at 5.11 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.
- How does the wet season affect solar generation in Rạch Giá?
- Rạch Giá's dry-season output peaks at 5.86 kWh/m²/day in April; the wet season drops it to 4.76 in December. That ~22% swing is a key sizing consideration.
- Can solar panels survive tropical storms in Rạch Giá?
- Most tier-1 PV panels are rated for 140+ mph wind loads; mounting hardware usually fails first. In cyclone-prone regions like Vietnam, specify IEC 61215-certified panels and anchor-bolt mounts rather than ballasted.
- What's the dry-to-wet output gap in Rạch Giá?
- Rạch Giá swings from 5.86 kWh/m²/day in April (dry) to 4.76 in December (wet) — roughly 22%. Year-round off-grid systems must size against the wet-season minimum.