JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-640/LB
VS
The verdict
640/LB leads on the differences that matter
The largest is module efficiency: 0.40 pp more efficient. 16 of 19 comparable parameters are identical.
See all 3 differencesHow alike are they
16
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
3 of 19 parameters
What actually differs
Parameter
630/LB
640/LB
Difference
Module efficiency
22.50 %
22.90 %
0.40 pp more efficient
Power density
225.4 Wp/m²
229.0 Wp/m²
3.6 Wp/m² higher
Rated power
630 Wp
640 Wp
10 W more power
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.
630/LB
21,138 kWh
640/LB
21,473 kWh
Lifetime gap
335 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
630/LB
640/LB
Standard test conditions
25 °C
100.0% of rated power
630 W
640 W
Cool, bright day
40 °C
95.7% of rated power
603 W
612 W
Typical summer roof
55 °C
91.3% of rated power
575 W
584 W
Hot roof
70 °C
87.0% of rated power
548 W
556 W
03
Full specification
Parameter
630/LB
640/LB
Difference
Power and efficiency
Rated power
630 Wp
640 Wp
+10 W for 640/LB
Module efficiency
22.50 %
22.90 %
+0.40 pp for 640/LB
Power density
225.4 Wp/m²
229.0 Wp/m²
+3.6 Wp/m² for 640/LB
Open-circuit voltage
52.47 V
52.87 V
Effectively the same
Voltage at max power
43.90 V
44.29 V
Effectively the same
Short-circuit current
15.21 A
15.31 A
Effectively the same
Current at max power
14.35 A
14.45 A
Effectively the same
Temperature
Temperature coefficient
-0.290 %/°C
-0.290 %/°C
Same
Mechanical
Dimensions
2465x1134x30 mm
2465x1134x30 mm
Same
Module area
2.795 m²
2.795 m²
Same
Weight
34.6 kg
34.6 kg
Same
Weight per kWp
54.9 kg/kWp
54.1 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
12 yrs
Same
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
0.40 %/yr
0.40 %/yr
Same
Technology
Cell technology
TOPCon
TOPCon
Same
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
144
144
Same
Bifacial
Yes
Yes
Same
04
14,005 panels
Against the whole database
Efficiency
#4,222
vs
#2,359
640/LB leads by 1,863 places
Power density
#3,907
vs
#2,389
640/LB leads by 1,518 places
Heat behaviour
#2,165
vs
#2,165
Tied - the same position in the database
Weight
#9,305
vs
#8,284
640/LB leads by 1,021 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#2,749
vs
#2,090
640/LB leads by 659 places
05
Open the full database
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06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM72D42-630/LB or JA Solar JAM72D42-640/LB?
According to our database: JA Solar JAM72D42-640/LB has higher module efficiency (22.90% vs 22.50%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM72D42-630/LB and JA Solar JAM72D42-640/LB?
JA Solar JAM72D42-630/LB has a module efficiency of 22.50%, while JA Solar JAM72D42-640/LB is 22.90%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM72D42-630/LB use vs JA Solar JAM72D42-640/LB?
JA Solar JAM72D42-630/LB uses TOPCon cells; JA Solar JAM72D42-640/LB 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 JA Solar JAM72D42-630/LB and JA Solar JAM72D42-640/LB?
JA Solar JAM72D42-630/LB has a 30 years power warranty; JA Solar JAM72D42-640/LB 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 JA Solar JAM72D42-630/LB and JA Solar JAM72D42-640/LB bifacial panels?
Both JA Solar JAM72D42-630/LB and JA Solar JAM72D42-640/LB 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 394 JA 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.
