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66Y18/DG-720 vs 78X16/DG-620W 6 of 18 identical Swap Change panels

DAH Solar DHN-66Y18/DG-720 vs DAH Solar DHN-78X16/DG-620W

DAH Solar
DHN-66Y18/DG-720
720 Wp 23.18 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
DAH Solar
DHN-78X16/DG-620W
620 Wp 22.18 % TOPCon Bifacial Incomplete
Open panel page Datasheet PDF
The verdict

66Y18/DG-720 leads on the differences that matter

The largest is module efficiency: 1.00 pp more efficient. 6 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 12 differences
How alike are they
6 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

12 of 18 parameters
Parameter 66Y18/DG-720 78X16/DG-620W Difference
Module efficiency 23.18 % 22.18 % 1.00 pp more efficient
Rated power 720 Wp 620 Wp 100 W more power
Power density 231.8 Wp/m² 221.8 Wp/m² 10.0 Wp/m² higher
Open-circuit voltage 48.40 V 55.60 V 7.20 V apart
Short-circuit current 18.73 A 14.08 A 4.65 A apart
Module area 3.106 m² 2.795 m² 0.311 m² apart
Weight 36.7 kg 34.2 kg 2.5 kg lighter
Weight per kWp 51.0 kg/kWp 55.2 kg/kWp 4.2 kg/kWp lighter
Voltage at max power 40.80 V 46.80 V 6.00 V apart
Current at max power 17.65 A 13.25 A 4.40 A apart
Cell count 132 156 24 cells apart
Dimensions 2384x1303x33 mm 2465x1134x34 mm 2384x1303x33 mm vs 2465x1134x34 mm
02

What it means on a roof

Thirty years of production
A 1.0% first-year loss then 0.40% a year, assumed for both panels, at 1,200 kWh/kWp a year
Same temp coeff. for both panels (-0.290 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
66Y18/DG-720
24,157 kWh
78X16/DG-620W
20,802 kWh
Lifetime gap
3,355 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 66Y18/DG-720 78X16/DG-620W
Standard test conditions 25 °C 100.0% of rated power 720 W 620 W
Cool, bright day 40 °C 95.7% of rated power 689 W 593 W
Typical summer roof 55 °C 91.3% of rated power 657 W 566 W
Hot roof 70 °C 87.0% of rated power 626 W 539 W
03

Full specification

Parameter 66Y18/DG-720 78X16/DG-620W Difference
Power and efficiency
Rated power 720 Wp 620 Wp +100 W for 66Y18/DG-720
Module efficiency 23.18 % 22.18 % +1.00 pp for 66Y18/DG-720
Power density 231.8 Wp/m² 221.8 Wp/m² +10.0 Wp/m² for 66Y18/DG-720
Open-circuit voltage 48.40 V 55.60 V 7.20 V apart
Voltage at max power 40.80 V 46.80 V 6.00 V apart
Short-circuit current 18.73 A 14.08 A 4.65 A apart
Current at max power 17.65 A 13.25 A 4.40 A apart
Temperature
Temperature coefficient -0.290 %/°C -0.290 %/°C Same
Mechanical
Dimensions 2384x1303x33 mm 2465x1134x34 mm 2384x1303x33 mm vs 2465x1134x34 mm
Module area 3.106 m² 2.795 m² 0.311 m² apart
Weight 36.7 kg 34.2 kg -2.5 kg for 78X16/DG-620W
Weight per kWp 51.0 kg/kWp 55.2 kg/kWp -4.2 kg/kWp for 66Y18/DG-720
Warranty and degradation
Product warranty 15 yrs 15 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/yr - Not published by DAH Solar
Technology
Cell technology TOPCon TOPCon Same
Cell type Monocrystalline Monocrystalline Same
Cell count 132 156 24 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#1,424 vs #5,930
66Y18/DG-720 leads by 4,506 places
Power density
#1,347 vs #5,869
66Y18/DG-720 leads by 4,522 places
Heat behaviour
#2,165 vs #2,165
Tied - the same position in the database
Weight
#4,335 vs #9,586
66Y18/DG-720 leads by 5,251 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#348 vs #2,865
66Y18/DG-720 leads by 2,517 places
05

More useful comparisons

Open the full database
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06

Written summary

07

Questions about this pairing

Which panel is better: DAH Solar DHN-66Y18/DG-720 or DAH Solar DHN-78X16/DG-620W?
According to our database: DAH Solar DHN-66Y18/DG-720 has higher module efficiency (23.18% vs 22.18%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of DAH Solar DHN-66Y18/DG-720 and DAH Solar DHN-78X16/DG-620W?
DAH Solar DHN-66Y18/DG-720 has a module efficiency of 23.18%, while DAH Solar DHN-78X16/DG-620 W is 22.18%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does DAH Solar DHN-66Y18/DG-720 use vs DAH Solar DHN-78X16/DG-620W?
DAH Solar DHN-66Y18/DG-720 uses TOPCon cells; DAH Solar DHN-78X16/DG-620 W uses TOPCon. Modern n-type technologies (TOPCon, HJT, BC) typically deliver higher efficiency and lower degradation compared to older PERC (p-type) cells.
What is the warranty on DAH Solar DHN-66Y18/DG-720 and DAH Solar DHN-78X16/DG-620W?
DAH Solar DHN-66Y18/DG-720 has a 30 years power warranty; DAH Solar DHN-78X16/DG-620 W has a 30 years power warranty. The power warranty guarantees a minimum percentage of rated output at the end of the warranty period (typically 80-87%). Product (materials) warranties are usually shorter.
Are DAH Solar DHN-66Y18/DG-720 and DAH Solar DHN-78X16/DG-620W bifacial panels?
Both DAH Solar DHN-66Y18/DG-720 and DAH Solar DHN-78X16/DG-620 W are bifacial - they capture reflected light from the ground, which can add 5-15% more annual energy on ground-mount or elevated rooftop installations with a light surface beneath.

Shop prices: See 11 DAH Solar offers

Every figure here is from the manufacturers' own datasheets - a dash means the value is not published, never an estimate. The thirty-year projection and the temperature scenarios are calculations from those figures, and each states its assumption above.