JA Solar JAM54D41-450/LR vs JA Solar JAM66D45-625/LB
VS
The verdict
14 differences, and they point both ways
The largest is rated power: 175 W more power. 5 of 19 comparable parameters are identical.
See all 14 differencesHow alike are they
5
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
14 of 19 parameters
What actually differs
Parameter
JAM54D41-450/LR
JAM66D45-625/LB
Difference
Rated power
450 Wp
625 Wp
175 W more power
Module efficiency
22.50 %
23.10 %
0.60 pp more efficient
Weight
22.0 kg
33.1 kg
11.1 kg lighter
Product warranty
15 yrs
12 yrs
3 yrs longer
Power density
225.2 Wp/m²
231.4 Wp/m²
6.2 Wp/m² higher
Open-circuit voltage
40.30 V
48.70 V
8.40 V apart
Module area
1.998 m²
2.701 m²
0.703 m² apart
Short-circuit current
14.41 A
16.15 A
1.74 A apart
Weight per kWp
48.9 kg/kWp
53.0 kg/kWp
4.1 kg/kWp lighter
Voltage at max power
32.99 V
40.45 V
7.46 V apart
Cell count
108
132
24 cells apart
Current at max power
13.64 A
15.45 A
1.81 A apart
Bifacial
No
Yes
No vs Yes
Dimensions
1762x1134x30 mm
2382x1134x30 mm
1762x1134x30 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.
JAM54D41-450/LR
15,098 kWh
JAM66D45-625/LB
20,970 kWh
Lifetime gap
5,872 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
JAM54D41-450/LR
JAM66D45-625/LB
Standard test conditions
25 °C
100.0% of rated power
450 W
625 W
Cool, bright day
40 °C
95.7% of rated power
430 W
598 W
Typical summer roof
55 °C
91.3% of rated power
411 W
571 W
Hot roof
70 °C
87.0% of rated power
391 W
543 W
03
Full specification
Parameter
JAM54D41-450/LR
JAM66D45-625/LB
Difference
Power and efficiency
Rated power
450 Wp
625 Wp
+175 W for JAM66D45-625/LB
Module efficiency
22.50 %
23.10 %
+0.60 pp for JAM66D45-625/LB
Power density
225.2 Wp/m²
231.4 Wp/m²
+6.2 Wp/m² for JAM66D45-625/LB
Open-circuit voltage
40.30 V
48.70 V
8.40 V apart
Voltage at max power
32.99 V
40.45 V
7.46 V apart
Short-circuit current
14.41 A
16.15 A
1.74 A apart
Current at max power
13.64 A
15.45 A
1.81 A apart
Temperature
Temperature coefficient
-0.290 %/°C
-0.290 %/°C
Same
Mechanical
Dimensions
1762x1134x30 mm
2382x1134x30 mm
1762x1134x30 mm vs 2382x1134x30 mm
Module area
1.998 m²
2.701 m²
0.703 m² apart
Weight
22.0 kg
33.1 kg
-11.1 kg for JAM54D41-450/LR
Weight per kWp
48.9 kg/kWp
53.0 kg/kWp
-4.1 kg/kWp for JAM54D41-450/LR
Warranty and degradation
Product warranty
15 yrs
12 yrs
+3 yrs for JAM54D41-450/LR
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
108
132
24 cells apart
Bifacial
No
Yes
No vs Yes
04
14,005 panels
Against the whole database
Efficiency
#4,222
vs
#1,570
JAM66D45-625/LB leads by 2,652 places
Power density
#4,225
vs
#1,513
JAM66D45-625/LB leads by 2,712 places
Heat behaviour
#2,165
vs
#2,165
Tied - the same position in the database
Weight
#2,563
vs
#6,680
JAM54D41-450/LR leads by 4,117 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#8,397
vs
#2,270
JAM66D45-625/LB leads by 6,127 places
05
Open the full database
More useful comparisons
Same series, other bin
JA Solar JAM54D41-450/LR vs JA Solar JAM54D41-455/LR
One difference: module efficiency
Same series, other bin
JA Solar JAM54D41-450/LR vs JA Solar JAM54D41-445/LR
2 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54D41-450/LR vs JA Solar JAM54D41-440/LR
4 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM66D45-625/LB vs JA Solar JAM66D45-630/LB
One difference: module efficiency
Same series, other bin
JA Solar JAM66D45-625/LB vs JA Solar JAM66D45-620/LB
The same specification on paper
Same series, other bin
JA Solar JAM66D45-625/LB vs JA Solar JAM66D45-615/LB
3 differences, the largest is module efficiency
06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM54D41-450/LR or JA Solar JAM66D45-625/LB?
According to our database: JA Solar JAM66D45-625/LB has higher module efficiency (23.10% 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 JAM54D41-450/LR and JA Solar JAM66D45-625/LB?
JA Solar JAM54D41-450/LR has a module efficiency of 22.50%, 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 JAM54D41-450/LR use vs JA Solar JAM66D45-625/LB?
JA Solar JAM54D41-450/LR 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 JAM54D41-450/LR and JA Solar JAM66D45-625/LB?
JA Solar JAM54D41-450/LR 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 JAM54D41-450/LR and JA Solar JAM66D45-625/LB bifacial panels?
JA Solar JAM66D45-625/LB is bifacial (captures light from both faces); JA Solar JAM54D41-450/LR is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.
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.