JA Solar JAM66D46-740/LB vs JA Solar JAM72S20-450/MR
VS
The verdict
JAM66D46-740/LB leads on the differences that matter
The largest is module efficiency: 3.50 pp more efficient. 4 of 19 comparable parameters are identical.
See all 15 differencesHow alike are they
4
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
15 of 19 parameters
What actually differs
Parameter
JAM66D46-740/LB
JAM72S20-450/MR
Difference
Module efficiency
23.80 %
20.30 %
3.50 pp more efficient
Temperature coefficient
-0.290 %/°C
-0.350 %/°C
0.060 %/°C better in heat
Rated power
740 Wp
450 Wp
290 W more power
Power density
238.2 Wp/m²
202.5 Wp/m²
35.7 Wp/m² higher
Performance warranty
30 yrs
25 yrs
5 yrs longer
Annual degradation
0.40 %/yr
0.55 %/yr
0.15 %/yr slower
Weight
38.2 kg
24.5 kg
13.7 kg lighter
Short-circuit current
18.73 A
11.36 A
7.37 A apart
Module area
3.106 m²
2.222 m²
0.885 m² apart
Cell technology
TOPCon
PERC
TOPCon vs PERC
Weight per kWp
51.6 kg/kWp
54.4 kg/kWp
2.8 kg/kWp lighter
Current at max power
17.64 A
10.84 A
6.80 A apart
Cell count
132
144
12 cells apart
Bifacial
Yes
No
Yes vs No
Dimensions
2384x1303x33 mm
2112x1052x35 mm
2384x1303x33 mm vs 2112x1052x35 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
JAM66D46-740/LB
24,828 kWh
JAM72S20-450/MR
14,584 kWh
Lifetime gap
10,244 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
JAM66D46-740/LB
JAM72S20-450/MR
Standard test conditions
25 °C
100.0% of rated power
740 W
450 W
Cool, bright day
40 °C
94.8% of rated power
708 W
426 W
Typical summer roof
55 °C
89.5% of rated power
676 W
403 W
Hot roof
70 °C
84.2% of rated power
643 W
379 W
03
Full specification
Parameter
JAM66D46-740/LB
JAM72S20-450/MR
Difference
Power and efficiency
Rated power
740 Wp
450 Wp
+290 W for JAM66D46-740/LB
Module efficiency
23.80 %
20.30 %
+3.50 pp for JAM66D46-740/LB
Power density
238.2 Wp/m²
202.5 Wp/m²
+35.7 Wp/m² for JAM66D46-740/LB
Open-circuit voltage
49.80 V
49.70 V
Effectively the same
Voltage at max power
41.96 V
41.52 V
Effectively the same
Short-circuit current
18.73 A
11.36 A
7.37 A apart
Current at max power
17.64 A
10.84 A
6.80 A apart
Temperature
Temperature coefficient
-0.290 %/°C
-0.350 %/°C
+0.060 %/°C for JAM66D46-740/LB
Mechanical
Dimensions
2384x1303x33 mm
2112x1052x35 mm
2384x1303x33 mm vs 2112x1052x35 mm
Module area
3.106 m²
2.222 m²
0.885 m² apart
Weight
38.2 kg
24.5 kg
-13.7 kg for JAM72S20-450/MR
Weight per kWp
51.6 kg/kWp
54.4 kg/kWp
-2.8 kg/kWp for JAM66D46-740/LB
Warranty and degradation
Product warranty
12 yrs
12 yrs
Same
Performance warranty
30 yrs
25 yrs
+5 yrs for JAM66D46-740/LB
Annual degradation
0.40 %/yr
0.55 %/yr
-0.15 %/yr for JAM66D46-740/LB
Technology
Cell technology
TOPCon
PERC
TOPCon vs PERC
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
132
144
12 cells apart
Bifacial
Yes
No
Yes vs No
04
14,005 panels
Against the whole database
Efficiency
#433
vs
#11,769
JAM66D46-740/LB leads by 11,336 places
Power density
#431
vs
#11,847
JAM66D46-740/LB leads by 11,416 places
Heat behaviour
#2,165
vs
#10,419
JAM66D46-740/LB leads by 8,254 places
Weight
#4,997
vs
#8,755
JAM66D46-740/LB leads by 3,758 places
Warranty
#21
vs
#9,798
JAM66D46-740/LB leads by 9,777 places
Overall
#185
vs
#11,425
JAM66D46-740/LB leads by 11,240 places
05
Open the full database
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06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM66D46-740/LB or JA Solar JAM72S20-450/MR?
According to our database: JA Solar JAM66D46-740/LB has higher module efficiency (23.80% vs 20.30%); JA Solar JAM66D46-740/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 JAM66D46-740/LB and JA Solar JAM72S20-450/MR?
JA Solar JAM66D46-740/LB has a module efficiency of 23.80%, while JA Solar JAM72S20-450/MR is 20.30%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM66D46-740/LB use vs JA Solar JAM72S20-450/MR?
JA Solar JAM66D46-740/LB uses TOPCon cells; JA Solar JAM72S20-450/MR uses PERC. 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 JAM66D46-740/LB and JA Solar JAM72S20-450/MR?
JA Solar JAM66D46-740/LB has a 30 years power warranty; JA Solar JAM72S20-450/MR has a 25 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 JAM66D46-740/LB and JA Solar JAM72S20-450/MR bifacial panels?
JA Solar JAM66D46-740/LB is bifacial (captures light from both faces); JA Solar JAM72S20-450/MR is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.
Shop prices: See 391 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.