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Peak Sun Hours in Đống Đa, Hanoi, Vietnam

3.7
kWh/m²/day (annual avg)
Solar zone
Zone 2 (moderate)
Best month
June (5.0)
Worst month
January (2.2)
Climate
Tropical · 23.3°C

Monthly solar breakdown

J: 2.24 kWh/m²/day F: 2.65 kWh/m²/day M: 2.97 kWh/m²/day A: 3.76 kWh/m²/day M: 4.74 kWh/m²/day J: 4.95 kWh/m²/day J: 4.83 kWh/m²/day A: 4.68 kWh/m²/day S: 4.5 kWh/m²/day O: 3.76 kWh/m²/day N: 3.24 kWh/m²/day D: 2.54 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 2.24 4.55 1.25 1.45 15.4 81
Feb 2.65 5.17 1.16 1.76 18.2 80
Mar 2.97 5.55 0.81 2.09 21.4 80
Apr 3.76 6.37 1.29 2.46 25.1 78
May 4.74 7.14 2.29 2.72 27.5 80
Jun 4.95 7.26 2.16 3.03 28.5 84
Jul 4.83 7.31 2.30 2.86 28.4 85
Aug 4.68 7.01 2.32 2.70 27.9 86
Sep 4.50 6.41 2.56 2.47 26.7 85
Oct 3.76 5.39 2.32 2.05 23.8 84
Nov 3.24 4.78 2.64 1.62 20.3 82
Dec 2.54 4.22 1.94 1.40 16.0 80

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 against worst-month PSH of 2.24 kWh/m²/day, 0.77 system efficiency.

About solar in Đống Đa

Đống Đa, Vietnam has a warm, tropical climate with a distinct wet and dry season. Its annual peak sun hours average 3.74 kWh/m²/day, a moderate solar resource by global standards.

The strongest month in Đống Đa is June (summer) at 4.95 kWh/m²/day, and the weakest is January (winter) at 2.24 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, Đống Đa installations typically oversize panels or combine solar with another source (grid, generator, hydro) for reliability.

FAQ

What are the peak sun hours in Đống Đa?
Đống Đa averages 3.74 peak sun hours per day annually, ranging from 2.24 in January to 4.95 in June.
How many solar panels do I need in Đống Đa?
Panel count depends on your daily load. At Đống Đa's annual average of 3.74 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 Đống Đa?
Sizing against Đống Đa's worst month (January, 2.24 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 Đống Đa's solar resource compare globally?
Đống Đa sits in solar zone 2 out of 5 (where 5 is strongest) at 3.74 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 does the wet season affect solar generation in Đống Đa?
Đống Đa's dry-season output peaks at 4.95 kWh/m²/day in June; the wet season drops it to 2.24 in January. That ~72% swing is a key sizing consideration.
Can solar panels survive tropical storms in Đống Đa?
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 Đống Đa?
Đống Đa swings from 4.95 kWh/m²/day in June (dry) to 2.24 in January (wet) — roughly 72%. Year-round off-grid systems must size against the wet-season minimum.