JA Solar JAM72D42-625/LB vs JA Solar JAM66D45-625/LB
VS
The verdict
JAM66D45-625/LB leads on the differences that matter
The largest is module efficiency: 0.70 pp more efficient. 8 of 19 comparable parameters are identical.
See all 11 differencesHow alike are they
8
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
11 of 19 parameters
What actually differs
Parameter
JAM72D42-625/LB
JAM66D45-625/LB
Difference
Module efficiency
22.40 %
23.10 %
0.70 pp more efficient
Power density
223.6 Wp/m²
231.4 Wp/m²
7.8 Wp/m² higher
Module area
2.795 m²
2.701 m²
0.094 m² apart
Open-circuit voltage
52.27 V
48.70 V
3.57 V apart
Weight
34.6 kg
33.1 kg
1.5 kg lighter
Cell count
144
132
12 cells apart
Short-circuit current
15.16 A
16.15 A
0.99 A apart
Weight per kWp
55.4 kg/kWp
53.0 kg/kWp
2.4 kg/kWp lighter
Voltage at max power
43.71 V
40.45 V
3.26 V apart
Current at max power
14.30 A
15.45 A
1.15 A apart
Dimensions
2465x1134x30 mm
2382x1134x30 mm
2465x1134x30 mm vs 2382x1134x30 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
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.
JAM72D42-625/LB
20,970 kWh
JAM66D45-625/LB
20,970 kWh
Lifetime gap
No difference
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
JAM72D42-625/LB
JAM66D45-625/LB
Standard test conditions
25 °C
100.0% of rated power
625 W
625 W
Cool, bright day
40 °C
95.7% of rated power
598 W
598 W
Typical summer roof
55 °C
91.3% of rated power
571 W
571 W
Hot roof
70 °C
87.0% of rated power
543 W
543 W
03
Full specification
Parameter
JAM72D42-625/LB
JAM66D45-625/LB
Difference
Power and efficiency
Rated power
625 Wp
625 Wp
Same
Module efficiency
22.40 %
23.10 %
+0.70 pp for JAM66D45-625/LB
Power density
223.6 Wp/m²
231.4 Wp/m²
+7.8 Wp/m² for JAM66D45-625/LB
Open-circuit voltage
52.27 V
48.70 V
3.57 V apart
Voltage at max power
43.71 V
40.45 V
3.26 V apart
Short-circuit current
15.16 A
16.15 A
0.99 A apart
Current at max power
14.30 A
15.45 A
1.15 A apart
Temperature
Temperature coefficient
-0.290 %/°C
-0.290 %/°C
Same
Mechanical
Dimensions
2465x1134x30 mm
2382x1134x30 mm
2465x1134x30 mm vs 2382x1134x30 mm
Module area
2.795 m²
2.701 m²
0.094 m² apart
Weight
34.6 kg
33.1 kg
-1.5 kg for JAM66D45-625/LB
Weight per kWp
55.4 kg/kWp
53.0 kg/kWp
-2.4 kg/kWp for JAM66D45-625/LB
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
132
12 cells apart
Bifacial
Yes
Yes
Same
04
14,005 panels
Against the whole database
Efficiency
#4,774
vs
#1,570
JAM66D45-625/LB leads by 3,204 places
Power density
#4,955
vs
#1,513
JAM66D45-625/LB leads by 3,442 places
Heat behaviour
#2,165
vs
#2,165
Tied - the same position in the database
Weight
#9,802
vs
#6,680
JAM66D45-625/LB leads by 3,122 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#3,028
vs
#2,270
JAM66D45-625/LB leads by 758 places
05
Open the full database
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The same specification on paper
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06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM72D42-625/LB or JA Solar JAM66D45-625/LB?
According to our database: JA Solar JAM66D45-625/LB has higher module efficiency (23.10% vs 22.40%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM72D42-625/LB and JA Solar JAM66D45-625/LB?
JA Solar JAM72D42-625/LB has a module efficiency of 22.40%, while JA Solar JAM66D45-625/LB is 23.10%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM72D42-625/LB use vs JA Solar JAM66D45-625/LB?
JA Solar JAM72D42-625/LB uses TOPCon cells; JA Solar JAM66D45-625/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 JAM72D42-625/LB and JA Solar JAM66D45-625/LB?
JA Solar JAM72D42-625/LB has a 30 years power warranty; JA Solar JAM66D45-625/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 JAM72D42-625/LB and JA Solar JAM66D45-625/LB bifacial panels?
Both JA Solar JAM72D42-625/LB and JA Solar JAM66D45-625/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 384 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.