Silfab SIL-420 QD vs Silfab SIL-440 QD
VS
The verdict
440 QD leads on the differences that matter
The largest is module efficiency: 1.10 pp more efficient. 13 of 19 comparable parameters are identical.
See all 6 differencesHow alike are they
13
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
6 of 19 parameters
What actually differs
Parameter
420 QD
440 QD
Difference
Module efficiency
21.50 %
22.60 %
1.10 pp more efficient
Power density
215.4 Wp/m²
225.7 Wp/m²
10.3 Wp/m² higher
Annual degradation
0.40 %/yr
0.30 %/yr
0.10 %/yr slower
Rated power
420 Wp
440 Wp
20 W more power
Weight per kWp
50.0 kg/kWp
47.7 kg/kWp
2.3 kg/kWp lighter
Short-circuit current
13.50 A
14.22 A
0.72 A apart
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.
420 QD
13,941 kWh
440 QD
14,834 kWh
Lifetime gap
893 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
420 QD
440 QD
Standard test conditions
25 °C
100.0% of rated power
420 W
440 W
Cool, bright day
40 °C
95.7% of rated power
402 W
421 W
Typical summer roof
55 °C
91.3% of rated power
383 W
402 W
Hot roof
70 °C
87.0% of rated power
365 W
383 W
03
Full specification
Parameter
420 QD
440 QD
Difference
Power and efficiency
Rated power
420 Wp
440 Wp
+20 W for 440 QD
Module efficiency
21.50 %
22.60 %
+1.10 pp for 440 QD
Power density
215.4 Wp/m²
225.7 Wp/m²
+10.3 Wp/m² for 440 QD
Open-circuit voltage
38.84 V
38.97 V
Effectively the same
Voltage at max power
33.08 V
33.41 V
Effectively the same
Short-circuit current
13.50 A
14.22 A
0.72 A apart
Current at max power
12.70 A
13.17 A
Effectively the same
Temperature
Temperature coefficient
-0.290 %/°C
-0.290 %/°C
Same
Mechanical
Dimensions
1721x1133x35 mm
1721x1133x35 mm
Same
Module area
1.950 m²
1.950 m²
Same
Weight
21.0 kg
21.0 kg
Same
Weight per kWp
50.0 kg/kWp
47.7 kg/kWp
-2.3 kg/kWp for 440 QD
Warranty and degradation
Product warranty
25 yrs
25 yrs
Same
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
0.40 %/yr
0.30 %/yr
-0.10 %/yr for 440 QD
Technology
Cell technology
N-type
N-type
Same
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
108
108
Same
Bifacial
No
No
Same
04
14,005 panels
Against the whole database
Efficiency
#7,958
vs
#3,658
440 QD leads by 4,300 places
Power density
#7,783
vs
#3,848
440 QD leads by 3,935 places
Heat behaviour
#2,165
vs
#2,165
Tied - the same position in the database
Weight
#3,317
vs
#1,829
440 QD leads by 1,488 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#8,547
vs
#6,331
440 QD leads by 2,216 places
05
Open the full database
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06
Written summary
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07
Questions about this pairing
Which panel is better: Silfab SIL-420 QD or Silfab SIL-440 QD?
According to our database: Silfab SIL-440 QD has higher module efficiency (22.60% vs 21.50%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Silfab SIL-420 QD and Silfab SIL-440 QD?
Silfab SIL-420 QD has a module efficiency of 21.50%, while Silfab SIL-440 QD is 22.60%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Silfab SIL-420 QD use vs Silfab SIL-440 QD?
Silfab SIL-420 QD uses N-type cells; Silfab SIL-440 QD 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-420 QD and Silfab SIL-440 QD?
Silfab SIL-420 QD has a 30 years power warranty; Silfab SIL-440 QD 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.
Shop prices: See 2 Silfab 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.