Silfab SIL-370 NT mono PERC vs Silfab SIL-640 XL
VS
The verdict
640 XL leads on the differences that matter
The largest is module efficiency: 4.22 pp more efficient. 3 of 19 comparable parameters are identical.
See all 16 differencesHow alike are they
3
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
16 of 19 parameters
What actually differs
Parameter
370 NT mono PERC
640 XL
Difference
Module efficiency
18.70 %
22.92 %
4.22 pp more efficient
Temperature coefficient
-0.380 %/°C
-0.290 %/°C
0.090 %/°C better in heat
Rated power
370 Wp
640 Wp
270 W more power
Power density
186.9 Wp/m²
229.2 Wp/m²
42.3 Wp/m² higher
Annual degradation
0.50 %/yr
0.30 %/yr
0.20 %/yr slower
Weight
21.5 kg
29.5 kg
8.0 kg lighter
Weight per kWp
58.1 kg/kWp
46.1 kg/kWp
12.0 kg/kWp lighter
Open-circuit voltage
47.50 V
57.76 V
10.26 V apart
Short-circuit current
9.90 A
13.76 A
3.86 A apart
Module area
1.980 m²
2.793 m²
0.813 m² apart
Cell technology
PERC
N-type
PERC vs N-type
Voltage at max power
38.10 V
48.78 V
10.68 V apart
Current at max power
9.70 A
13.12 A
3.42 A apart
Cell count
72
156
84 cells apart
Bifacial
No
Yes
No vs Yes
Dimensions
1992x994x38 mm
2465x1133x35 mm
1992x994x38 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
370 NT mono PERC
11,968 kWh
640 XL
21,577 kWh
Lifetime gap
9,609 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
370 NT mono PERC
640 XL
Standard test conditions
25 °C
100.0% of rated power
370 W
640 W
Cool, bright day
40 °C
94.3% of rated power
349 W
612 W
Typical summer roof
55 °C
88.6% of rated power
328 W
584 W
Hot roof
70 °C
82.9% of rated power
307 W
556 W
03
Full specification
Parameter
370 NT mono PERC
640 XL
Difference
Power and efficiency
Rated power
370 Wp
640 Wp
+270 W for 640 XL
Module efficiency
18.70 %
22.92 %
+4.22 pp for 640 XL
Power density
186.9 Wp/m²
229.2 Wp/m²
+42.3 Wp/m² for 640 XL
Open-circuit voltage
47.50 V
57.76 V
10.26 V apart
Voltage at max power
38.10 V
48.78 V
10.68 V apart
Short-circuit current
9.90 A
13.76 A
3.86 A apart
Current at max power
9.70 A
13.12 A
3.42 A apart
Temperature
Temperature coefficient
-0.380 %/°C
-0.290 %/°C
+0.090 %/°C for 640 XL
Mechanical
Dimensions
1992x994x38 mm
2465x1133x35 mm
1992x994x38 mm vs 2465x1133x35 mm
Module area
1.980 m²
2.793 m²
0.813 m² apart
Weight
21.5 kg
29.5 kg
-8.0 kg for 370 NT mono PERC
Weight per kWp
58.1 kg/kWp
46.1 kg/kWp
-12.0 kg/kWp for 640 XL
Warranty and degradation
Product warranty
25 yrs
25 yrs
Same
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
0.50 %/yr
0.30 %/yr
-0.20 %/yr for 640 XL
Technology
Cell technology
PERC
N-type
PERC vs N-type
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
72
156
84 cells apart
Bifacial
No
Yes
No vs Yes
04
14,005 panels
Against the whole database
Efficiency
#13,058
vs
#2,350
640 XL leads by 10,708 places
Power density
#13,048
vs
#2,379
640 XL leads by 10,669 places
Heat behaviour
#13,397
vs
#2,165
640 XL leads by 11,232 places
Weight
#11,565
vs
#1,004
640 XL leads by 10,561 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#11,845
vs
#650
640 XL leads by 11,195 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-370 NT mono PERC or Silfab SIL-640 XL?
According to our database: Silfab SIL-640 XL has higher module efficiency (22.92% vs 18.70%); Silfab SIL-640 XL tolerates heat better (temp coeff -0.290%/°C vs -0.380%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Silfab SIL-370 NT mono PERC and Silfab SIL-640 XL?
Silfab SIL-370 NT mono PERC has a module efficiency of 18.70%, 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-370 NT mono PERC use vs Silfab SIL-640 XL?
Silfab SIL-370 NT mono PERC uses PERC 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-370 NT mono PERC and Silfab SIL-640 XL?
Silfab SIL-370 NT mono PERC 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-370 NT mono PERC and Silfab SIL-640 XL bifacial panels?
Silfab SIL-640 XL is bifacial (captures light from both faces); Silfab SIL-370 NT mono PERC 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.