JA Solar JAM54S30-390/MR vs JA Solar JAM66D46-735/LB
VS
The verdict
JAM66D46-735/LB leads on the differences that matter
The largest is module efficiency: 3.70 pp more efficient. 3 of 19 comparable parameters are identical.
See all 16 differencesHow alike are they
3
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
16 of 19 parameters
What actually differs
Parameter
JAM54S30-390/MR
JAM66D46-735/LB
Difference
Module efficiency
20.00 %
23.70 %
3.70 pp more efficient
Temperature coefficient
-0.350 %/°C
-0.290 %/°C
0.060 %/°C better in heat
Rated power
390 Wp
735 Wp
345 W more power
Power density
199.7 Wp/m²
236.6 Wp/m²
36.9 Wp/m² higher
Performance warranty
25 yrs
30 yrs
5 yrs longer
Annual degradation
0.55 %/yr
0.40 %/yr
0.15 %/yr slower
Weight
19.5 kg
38.2 kg
18.7 kg lighter
Open-circuit voltage
36.85 V
49.60 V
12.75 V apart
Short-circuit current
13.61 A
18.70 A
5.09 A apart
Module area
1.953 m²
3.106 m²
1.154 m² apart
Cell technology
PERC
TOPCon
PERC vs TOPCon
Voltage at max power
30.64 V
41.77 V
11.13 V apart
Current at max power
12.73 A
17.60 A
4.87 A apart
Cell count
108
132
24 cells apart
Bifacial
No
Yes
No vs Yes
Dimensions
1722x1134x30 mm
2384x1303x33 mm
1722x1134x30 mm vs 2384x1303x33 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
JAM54S30-390/MR
12,640 kWh
JAM66D46-735/LB
24,661 kWh
Lifetime gap
12,021 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
JAM54S30-390/MR
JAM66D46-735/LB
Standard test conditions
25 °C
100.0% of rated power
390 W
735 W
Cool, bright day
40 °C
94.8% of rated power
370 W
703 W
Typical summer roof
55 °C
89.5% of rated power
349 W
671 W
Hot roof
70 °C
84.2% of rated power
329 W
639 W
03
Full specification
Parameter
JAM54S30-390/MR
JAM66D46-735/LB
Difference
Power and efficiency
Rated power
390 Wp
735 Wp
+345 W for JAM66D46-735/LB
Module efficiency
20.00 %
23.70 %
+3.70 pp for JAM66D46-735/LB
Power density
199.7 Wp/m²
236.6 Wp/m²
+36.9 Wp/m² for JAM66D46-735/LB
Open-circuit voltage
36.85 V
49.60 V
12.75 V apart
Voltage at max power
30.64 V
41.77 V
11.13 V apart
Short-circuit current
13.61 A
18.70 A
5.09 A apart
Current at max power
12.73 A
17.60 A
4.87 A apart
Temperature
Temperature coefficient
-0.350 %/°C
-0.290 %/°C
+0.060 %/°C for JAM66D46-735/LB
Mechanical
Dimensions
1722x1134x30 mm
2384x1303x33 mm
1722x1134x30 mm vs 2384x1303x33 mm
Module area
1.953 m²
3.106 m²
1.154 m² apart
Weight
19.5 kg
38.2 kg
-18.7 kg for JAM54S30-390/MR
Weight per kWp
50.0 kg/kWp
52.0 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
12 yrs
Same
Performance warranty
25 yrs
30 yrs
+5 yrs for JAM66D46-735/LB
Annual degradation
0.55 %/yr
0.40 %/yr
-0.15 %/yr for JAM66D46-735/LB
Technology
Cell technology
PERC
TOPCon
PERC vs TOPCon
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
#12,214
vs
#517
JAM66D46-735/LB leads by 11,697 places
Power density
#12,255
vs
#582
JAM66D46-735/LB leads by 11,673 places
Heat behaviour
#10,419
vs
#2,165
JAM66D46-735/LB leads by 8,254 places
Weight
#3,317
vs
#5,413
JAM54S30-390/MR leads by 2,096 places
Warranty
#9,798
vs
#21
JAM66D46-735/LB leads by 9,777 places
Overall
#12,390
vs
#233
JAM66D46-735/LB leads by 12,157 places
05
Open the full database
More useful comparisons
Same series, other bin
JA Solar JAM54S30-390/MR vs JA Solar JAM54S30-415/MR
4 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S30-390/MR vs JA Solar JAM54S30-410/MR
4 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S30-390/MR vs JA Solar JAM54S30-405/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S30-390/MR vs JA Solar JAM54S30-400/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S30-390/MR vs JA Solar JAM54S30-395/MR
One difference: module efficiency
Same series, other bin
JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-740/LB
The same specification on paper
06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM54S30-390/MR or JA Solar JAM66D46-735/LB?
According to our database: JA Solar JAM66D46-735/LB has higher module efficiency (23.70% vs 20.00%); JA Solar JAM66D46-735/LB tolerates heat better (temp coeff -0.290%/°C vs -0.350%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM54S30-390/MR and JA Solar JAM66D46-735/LB?
JA Solar JAM54S30-390/MR has a module efficiency of 20.00%, while JA Solar JAM66D46-735/LB is 23.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM54S30-390/MR use vs JA Solar JAM66D46-735/LB?
JA Solar JAM54S30-390/MR uses PERC cells; JA Solar JAM66D46-735/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 JAM54S30-390/MR and JA Solar JAM66D46-735/LB?
JA Solar JAM54S30-390/MR has a 25 years power warranty; JA Solar JAM66D46-735/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 JAM54S30-390/MR and JA Solar JAM66D46-735/LB bifacial panels?
JA Solar JAM66D46-735/LB is bifacial (captures light from both faces); JA Solar JAM54S30-390/MR is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.
Shop prices: See 390 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.

