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Peak Sun Hours in Busan, Busan, South Korea

3.9
kWh/m²/day (annual avg)
Solar zone
Zone 2 (moderate)
Best month
May (5.4)
Worst month
December (2.4)
Climate
Temperate · 14.0°C

Monthly solar breakdown

J: 2.57 kWh/m²/day F: 3.17 kWh/m²/day M: 4.15 kWh/m²/day A: 4.95 kWh/m²/day M: 5.37 kWh/m²/day J: 4.92 kWh/m²/day J: 4.55 kWh/m²/day A: 4.68 kWh/m²/day S: 3.78 kWh/m²/day O: 3.48 kWh/m²/day N: 2.69 kWh/m²/day D: 2.4 kWh/m²/day J F M A M J J A S O N D 6 0
Month GHI Clear-sky DNI DHI Temp °C Humid %
Jan 2.57 3.18 3.16 1.19 2.2 76
Feb 3.17 4.12 3.11 1.53 4.3 72
Mar 4.15 5.39 3.40 1.95 7.9 72
Apr 4.95 6.53 3.63 2.29 12.5 75
May 5.37 7.27 3.49 2.59 16.9 79
Jun 4.92 7.28 2.54 2.73 20.7 83
Jul 4.55 7.11 2.49 2.49 24.2 89
Aug 4.68 6.66 3.17 2.29 25.8 85
Sep 3.78 5.71 2.74 1.93 22.0 82
Oct 3.48 4.54 3.33 1.61 16.8 76
Nov 2.69 3.40 3.12 1.25 10.6 75
Dec 2.40 2.90 3.22 1.09 4.3 77

GHI, Clear-sky, DNI, DHI in kWh/m²/day. Data: NASA POWER climatology (long-term monthly averages).

Off-grid calculator

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Sizing

Daily load
0.00 kWh
Panel wattage
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Panel count (400W modules)
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Battery bank
0.0 kWh

Sizing against worst-month PSH of 2.40 kWh/m²/day, 0.77 system efficiency.

About solar in Busan

Busan, South Korea has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 3.89 kWh/m²/day, a moderate solar resource by global standards.

The strongest month in Busan is May (spring) at 5.37 kWh/m²/day, and the weakest is December (winter) at 2.4 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, Busan installations typically oversize panels or combine solar with another source (grid, generator, hydro) for reliability.

FAQ

What are the peak sun hours in Busan?
Busan averages 3.89 peak sun hours per day annually, ranging from 2.4 in December to 5.37 in May.
How many solar panels do I need in Busan?
Panel count depends on your daily load. At Busan's annual average of 3.89 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 Busan?
Sizing against Busan's worst month (December, 2.4 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 Busan's solar resource compare globally?
Busan sits in solar zone 2 out of 5 (where 5 is strongest) at 3.89 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 Busan?
Busan's worst month (December) delivers 2.4 kWh/m²/day — about 45% of the summer peak of 5.37. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
Do cloudy days significantly affect Busan's solar?
Partly. Diffuse light still produces 10–25% of clear-sky output. Busan's 3.89 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
What panel tilt works best in Busan?
At Busan's latitude (35°), a fixed tilt near 35° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.