Skip to main content
JAM72D40-615/LB vs JAM72D42-640/LB 11 of 19 identical Swap Change panels

JA Solar JAM72D40-615/LB vs JA Solar JAM72D42-640/LB

JA Solar JAM72D40-615/LB
JAM72D40-615/LB
615 Wp 23.20 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
JA Solar JAM72D42-640/LB
JAM72D42-640/LB
640 Wp 22.90 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

JAM72D40-615/LB leads on the differences that matter

The largest is rated power: 25 W more power. 11 of 19 comparable parameters are identical.

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

What actually differs

8 of 19 parameters
Parameter JAM72D40-615/LB JAM72D42-640/LB Difference
Rated power 615 Wp 640 Wp 25 W more power
Module area 2.646 m² 2.795 m² 0.150 m² apart
Module efficiency 23.20 % 22.90 % 0.30 pp more efficient
Weight 32.5 kg 34.6 kg 2.1 kg lighter
Power density 232.5 Wp/m² 229.0 Wp/m² 3.5 Wp/m² higher
Short-circuit current 14.61 A 15.31 A 0.70 A apart
Dimensions 2333x1134x30 mm 2465x1134x30 mm 2333x1134x30 mm vs 2465x1134x30 mm
Current at max power 13.89 A 14.45 A 0.56 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.
JAM72D40-615/LB
20,634 kWh
JAM72D42-640/LB
21,473 kWh
Lifetime gap
839 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario JAM72D40-615/LB JAM72D42-640/LB
Standard test conditions 25 °C 100.0% of rated power 615 W 640 W
Cool, bright day 40 °C 95.7% of rated power 588 W 612 W
Typical summer roof 55 °C 91.3% of rated power 561 W 584 W
Hot roof 70 °C 87.0% of rated power 535 W 556 W
03

Full specification

Parameter JAM72D40-615/LB JAM72D42-640/LB Difference
Power and efficiency
Rated power 615 Wp 640 Wp +25 W for JAM72D42-640/LB
Module efficiency 23.20 % 22.90 % +0.30 pp for JAM72D40-615/LB
Power density 232.5 Wp/m² 229.0 Wp/m² +3.5 Wp/m² for JAM72D40-615/LB
Open-circuit voltage 53.00 V 52.87 V Effectively the same
Voltage at max power 44.28 V 44.29 V Effectively the same
Short-circuit current 14.61 A 15.31 A 0.70 A apart
Current at max power 13.89 A 14.45 A 0.56 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 JAM72D40-615/LB
Weight per kWp 52.8 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

Against the whole database

14,005 panels
Efficiency
#1,306 vs #2,359
JAM72D40-615/LB leads by 1,053 places
Power density
#1,249 vs #2,389
JAM72D40-615/LB leads by 1,140 places
Heat behaviour
#2,165 vs #2,165
Tied - the same position in the database
Weight
#6,546 vs #8,284
JAM72D40-615/LB leads by 1,738 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#2,486 vs #2,090
JAM72D42-640/LB leads by 396 places
05

More useful comparisons

Open the full database
Same series, other bin
JA Solar JAM72D40-615/LB vs JA Solar JAM72D42-650/LB
6 differences, the largest is rated power
Same series, other bin
JA Solar JAM72D40-615/LB vs JA Solar JAM72D42-645/LB
6 differences, the largest is rated power
Same series, other bin
JA Solar JAM72D40-615/LB vs JA Solar JAM72D42-635/LB
8 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM72D40-615/LB vs JA Solar JAM72D42-630/LB
8 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM72D40-615/LB vs JA Solar JAM72D42-625/LB
8 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM72D40-615/LB vs JA Solar JAM72D40-610/LB
The same specification on paper
06

Written summary

07

Questions about this pairing

Which panel is better: JA Solar JAM72D40-615/LB or JA Solar JAM72D42-640/LB?
According to our database: JA Solar JAM72D40-615/LB has higher module efficiency (23.20% vs 22.90%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM72D40-615/LB and JA Solar JAM72D42-640/LB?
JA Solar JAM72D40-615/LB has a module efficiency of 23.20%, 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 JAM72D40-615/LB use vs JA Solar JAM72D42-640/LB?
JA Solar JAM72D40-615/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 JAM72D40-615/LB and JA Solar JAM72D42-640/LB?
JA Solar JAM72D40-615/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 JAM72D40-615/LB and JA Solar JAM72D42-640/LB bifacial panels?
Both JA Solar JAM72D40-615/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 389 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.