Peak Sun Hours in Gimpo-si, Gyeonggi-do, South Korea
- Solar zone
- Zone 2 (moderate)
- Best month
- May (5.6)
- Worst month
- December (2.1)
- Climate
- Temperate · 11.2°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 2.42 | 2.93 | 2.87 | 1.23 | -3.3 | 77 |
| Feb | 3.20 | 3.90 | 3.38 | 1.50 | -0.9 | 74 |
| Mar | 4.30 | 5.24 | 3.94 | 1.87 | 3.7 | 74 |
| Apr | 5.02 | 6.43 | 3.99 | 2.16 | 9.8 | 74 |
| May | 5.56 | 7.17 | 3.94 | 2.50 | 15.8 | 75 |
| Jun | 5.25 | 7.07 | 2.90 | 2.74 | 20.9 | 76 |
| Jul | 4.21 | 6.83 | 1.97 | 2.45 | 24.0 | 84 |
| Aug | 4.50 | 6.41 | 2.78 | 2.33 | 24.9 | 83 |
| Sep | 4.18 | 5.48 | 3.33 | 1.95 | 20.4 | 79 |
| Oct | 3.59 | 4.26 | 3.75 | 1.53 | 13.9 | 75 |
| Nov | 2.44 | 3.09 | 2.93 | 1.14 | 6.5 | 75 |
| Dec | 2.11 | 2.63 | 2.81 | 1.04 | -1.0 | 76 |
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 2.11 kWh/m²/day, 0.77 system efficiency.
About solar in Gimpo-si
Gimpo-si, South Korea has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 3.9 kWh/m²/day, a moderate solar resource by global standards.
The strongest month in Gimpo-si is May (spring) at 5.56 kWh/m²/day, and the weakest is December (winter) at 2.11 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.
Given the moderate resource, Gimpo-si installations typically oversize panels or combine solar with another source (grid, generator, hydro) for reliability.
FAQ
- What are the peak sun hours in Gimpo-si?
- Gimpo-si averages 3.9 peak sun hours per day annually, ranging from 2.11 in December to 5.56 in May.
- How many solar panels do I need in Gimpo-si?
- Panel count depends on your daily load. At Gimpo-si's annual average of 3.9 kWh/m²/day, a 5 kWh/day load needs roughly 5 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Gimpo-si?
- Sizing against Gimpo-si's worst month (December, 2.11 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 Gimpo-si's solar resource compare globally?
- Gimpo-si sits in solar zone 2 out of 5 (where 5 is strongest) at 3.9 kWh/m²/day — moderate 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 Gimpo-si?
- Gimpo-si's worst month (December) delivers 2.11 kWh/m²/day — about 38% of the summer peak of 5.56. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Gimpo-si's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Gimpo-si's 3.9 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Gimpo-si?
- At Gimpo-si's latitude (38°), a fixed tilt near 38° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.