JA Solar JAM72D40-610/LB vs JA Solar JAM72D42-635/LB
VS
The verdict
JAM72D40-610/LB leads on the differences that matter
The largest is module efficiency: 0.40 pp more efficient. 11 of 19 comparable parameters are identical.
See all 8 differencesHow alike are they
11
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
8 of 19 parameters
What actually differs
Parameter
JAM72D40-610/LB
JAM72D42-635/LB
Difference
Module efficiency
23.10 %
22.70 %
0.40 pp more efficient
Rated power
610 Wp
635 Wp
25 W more power
Module area
2.646 m²
2.795 m²
0.150 m² apart
Weight
32.5 kg
34.6 kg
2.1 kg lighter
Power density
230.6 Wp/m²
227.2 Wp/m²
3.4 Wp/m² higher
Short-circuit current
14.57 A
15.26 A
0.69 A apart
Dimensions
2333x1134x30 mm
2465x1134x30 mm
2333x1134x30 mm vs 2465x1134x30 mm
Current at max power
13.83 A
14.40 A
0.57 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.
JAM72D40-610/LB
20,467 kWh
JAM72D42-635/LB
21,306 kWh
Lifetime gap
839 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
JAM72D40-610/LB
JAM72D42-635/LB
Standard test conditions
25 °C
100.0% of rated power
610 W
635 W
Cool, bright day
40 °C
95.7% of rated power
583 W
607 W
Typical summer roof
55 °C
91.3% of rated power
557 W
580 W
Hot roof
70 °C
87.0% of rated power
530 W
552 W
03
Full specification
Parameter
JAM72D40-610/LB
JAM72D42-635/LB
Difference
Power and efficiency
Rated power
610 Wp
635 Wp
+25 W for JAM72D42-635/LB
Module efficiency
23.10 %
22.70 %
+0.40 pp for JAM72D40-610/LB
Power density
230.6 Wp/m²
227.2 Wp/m²
+3.4 Wp/m² for JAM72D40-610/LB
Open-circuit voltage
52.80 V
52.67 V
Effectively the same
Voltage at max power
44.11 V
44.10 V
Effectively the same
Short-circuit current
14.57 A
15.26 A
0.69 A apart
Current at max power
13.83 A
14.40 A
0.57 A apart
Temperature
Temperature coefficient
-0.290 %/°C
-0.290 %/°C
Same
Mechanical
Dimensions
2333x1134x30 mm
2465x1134x30 mm
2333x1134x30 mm vs 2465x1134x30 mm
Module area
2.646 m²
2.795 m²
0.150 m² apart
Weight
32.5 kg
34.6 kg
-2.1 kg for JAM72D40-610/LB
Weight per kWp
53.3 kg/kWp
54.5 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
#1,570
vs
#3,307
JAM72D40-610/LB leads by 1,737 places
Power density
#1,689
vs
#3,252
JAM72D40-610/LB leads by 1,563 places
Heat behaviour
#2,165
vs
#2,165
Tied - the same position in the database
Weight
#7,135
vs
#8,832
JAM72D40-610/LB leads by 1,697 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#2,742
vs
#2,396
JAM72D42-635/LB leads by 346 places
05
Open the full database
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The same specification on paper
06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM72D40-610/LB or JA Solar JAM72D42-635/LB?
According to our database: JA Solar JAM72D40-610/LB has higher module efficiency (23.10% vs 22.70%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM72D40-610/LB and JA Solar JAM72D42-635/LB?
JA Solar JAM72D40-610/LB has a module efficiency of 23.10%, while JA Solar JAM72D42-635/LB is 22.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM72D40-610/LB use vs JA Solar JAM72D42-635/LB?
JA Solar JAM72D40-610/LB uses TOPCon cells; JA Solar JAM72D42-635/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 JAM72D40-610/LB and JA Solar JAM72D42-635/LB?
JA Solar JAM72D40-610/LB has a 30 years power warranty; JA Solar JAM72D42-635/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 JAM72D40-610/LB and JA Solar JAM72D42-635/LB bifacial panels?
Both JA Solar JAM72D40-610/LB and JA Solar JAM72D42-635/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 393 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.

