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430-QD vs 640 XL 8 of 19 identical Swap Change panels

Silfab SIL-430-QD vs Silfab SIL-640 XL

Silfab SIL-430-QD
Silfab
SIL-430-QD
430 Wp 22.10 % N-type
Open panel page Datasheet PDF
VS
Silfab
SIL-640 XL
640 Wp 22.92 % N-type Bifacial
Open panel page Datasheet PDF
The verdict

640 XL leads on the differences that matter

The largest is module efficiency: 0.82 pp more efficient. 8 of 19 comparable parameters are identical.

See all 11 differences
How alike are they
8 of 19 comparable
parameters are identical
identical differs
01

What actually differs

11 of 19 parameters
Parameter 430-QD 640 XL Difference
Module efficiency 22.10 % 22.92 % 0.82 pp more efficient
Rated power 430 Wp 640 Wp 210 W more power
Weight 21.0 kg 29.5 kg 8.5 kg lighter
Power density 220.5 Wp/m² 229.2 Wp/m² 8.6 Wp/m² higher
Open-circuit voltage 38.91 V 57.76 V 18.85 V apart
Module area 1.950 m² 2.793 m² 0.843 m² apart
Weight per kWp 48.8 kg/kWp 46.1 kg/kWp 2.7 kg/kWp lighter
Voltage at max power 33.25 V 48.78 V 15.53 V apart
Cell count 108 156 48 cells apart
Bifacial No Yes No vs Yes
Dimensions 1721x1133x35 mm 2465x1133x35 mm 1721x1133x35 mm vs 2465x1133x35 mm
02

What it means on a roof

Thirty years of production
Each panel's own declared degradation curve, 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.
430-QD
14,497 kWh
640 XL
21,577 kWh
Lifetime gap
7,080 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 430-QD 640 XL
Standard test conditions 25 °C 100.0% of rated power 430 W 640 W
Cool, bright day 40 °C 95.7% of rated power 411 W 612 W
Typical summer roof 55 °C 91.3% of rated power 393 W 584 W
Hot roof 70 °C 87.0% of rated power 374 W 556 W
03

Full specification

Parameter 430-QD 640 XL Difference
Power and efficiency
Rated power 430 Wp 640 Wp +210 W for 640 XL
Module efficiency 22.10 % 22.92 % +0.82 pp for 640 XL
Power density 220.5 Wp/m² 229.2 Wp/m² +8.6 Wp/m² for 640 XL
Open-circuit voltage 38.91 V 57.76 V 18.85 V apart
Voltage at max power 33.25 V 48.78 V 15.53 V apart
Short-circuit current 13.87 A 13.76 A Effectively the same
Current at max power 12.93 A 13.12 A Effectively the same
Temperature
Temperature coefficient -0.290 %/°C -0.290 %/°C Same
Mechanical
Dimensions 1721x1133x35 mm 2465x1133x35 mm 1721x1133x35 mm vs 2465x1133x35 mm
Module area 1.950 m² 2.793 m² 0.843 m² apart
Weight 21.0 kg 29.5 kg -8.5 kg for 430-QD
Weight per kWp 48.8 kg/kWp 46.1 kg/kWp -2.7 kg/kWp for 640 XL
Warranty and degradation
Product warranty 25 yrs 25 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.30 %/yr 0.30 %/yr Same
Technology
Cell technology N-type N-type Same
Cell type Monocrystalline Monocrystalline Same
Cell count 108 156 48 cells apart
Bifacial No Yes No vs Yes
04

Against the whole database

14,005 panels
Efficiency
#6,012 vs #2,350
640 XL leads by 3,662 places
Power density
#6,191 vs #2,379
640 XL leads by 3,812 places
Heat behaviour
#2,165 vs #2,165
Tied - the same position in the database
Weight
#2,492 vs #1,004
640 XL leads by 1,488 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#7,342 vs #650
640 XL leads by 6,692 places
05

More useful comparisons

Open the full database
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Silfab SIL-430-QD vs Silfab SIL-440 QD
3 differences, the largest is module efficiency
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Silfab SIL-430-QD vs Silfab SIL-430 QD
The same specification on paper
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Silfab SIL-430-QD vs Silfab SIL-420 QD
4 differences, the largest is module efficiency
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Silfab SIL-430-QD vs Silfab SIL-370 NT mono PERC
14 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-640 XL vs Silfab SIL-630 XL
3 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-640 XL vs Silfab SIL-620 XL
3 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Silfab SIL-430-QD or Silfab SIL-640 XL?
According to our database: Silfab SIL-640 XL has higher module efficiency (22.92% vs 22.10%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Silfab SIL-430-QD and Silfab SIL-640 XL?
Silfab SIL-430-QD has a module efficiency of 22.10%, while Silfab SIL-640 XL is 22.92%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Silfab SIL-430-QD use vs Silfab SIL-640 XL?
Silfab SIL-430-QD uses N-type cells; Silfab SIL-640 XL uses N-type. 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 Silfab SIL-430-QD and Silfab SIL-640 XL?
Silfab SIL-430-QD has a 30 years power warranty; Silfab SIL-640 XL 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 Silfab SIL-430-QD and Silfab SIL-640 XL bifacial panels?
Silfab SIL-640 XL is bifacial (captures light from both faces); Silfab SIL-430-QD is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

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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.