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Peak Sun Hours in Hefei, Anhui, China

3.6
kWh/m²/day (annual avg)
Solar zone
Zone 2 (moderate)
Best month
July (4.9)
Worst month
January (2.1)
Climate
Temperate · 16.0°C

Monthly solar breakdown

J: 2.15 kWh/m²/day F: 2.55 kWh/m²/day M: 3.59 kWh/m²/day A: 4.32 kWh/m²/day M: 4.63 kWh/m²/day J: 4.38 kWh/m²/day J: 4.86 kWh/m²/day A: 4.58 kWh/m²/day S: 3.81 kWh/m²/day O: 3.22 kWh/m²/day N: 2.54 kWh/m²/day D: 2.17 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 2.15 3.25 2.03 1.14 2.0 75
Feb 2.55 4.08 1.85 1.42 4.9 76
Mar 3.59 5.23 2.24 1.95 10.0 74
Apr 4.32 6.20 2.35 2.38 16.2 72
May 4.63 6.75 2.31 2.56 21.8 70
Jun 4.38 6.70 1.69 2.64 25.8 73
Jul 4.86 6.87 2.60 2.56 28.3 81
Aug 4.58 6.39 2.55 2.41 27.5 81
Sep 3.81 5.57 2.23 2.07 23.2 77
Oct 3.22 4.48 2.48 1.61 17.4 72
Nov 2.54 3.51 2.49 1.21 10.7 73
Dec 2.17 3.04 2.42 1.04 3.7 74

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
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Panel wattage
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Panel count (400W modules)
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Battery bank
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Sizing against worst-month PSH of 2.15 kWh/m²/day, 0.77 system efficiency.

About solar in Hefei

Hefei, China has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 3.57 kWh/m²/day, a moderate solar resource by global standards.

The strongest month in Hefei is July (summer) at 4.86 kWh/m²/day, and the weakest is January (winter) at 2.15 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the January value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.

Given the moderate resource, Hefei installations typically oversize panels or combine solar with another source (grid, generator, hydro) for reliability.

FAQ

What are the peak sun hours in Hefei?
Hefei averages 3.57 peak sun hours per day annually, ranging from 2.15 in January to 4.86 in July.
How many solar panels do I need in Hefei?
Panel count depends on your daily load. At Hefei's annual average of 3.57 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 Hefei?
Sizing against Hefei's worst month (January, 2.15 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 Hefei's solar resource compare globally?
Hefei sits in solar zone 2 out of 5 (where 5 is strongest) at 3.57 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 Hefei?
Hefei's worst month (January) delivers 2.15 kWh/m²/day — about 44% of the summer peak of 4.86. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
Do cloudy days significantly affect Hefei's solar?
Partly. Diffuse light still produces 10–25% of clear-sky output. Hefei's 3.57 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
What panel tilt works best in Hefei?
At Hefei's latitude (32°), a fixed tilt near 32° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.