JA Solar JAM72S20-445/MR vs JA Solar JAM66D46-740/LB
VS
The verdict
JAM66D46-740/LB leads on the differences that matter
The largest is module efficiency: 3.80 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
JAM72S20-445/MR
JAM66D46-740/LB
Difference
Module efficiency
20.00 %
23.80 %
3.80 pp more efficient
Temperature coefficient
-0.350 %/°C
-0.290 %/°C
0.060 %/°C better in heat
Rated power
445 Wp
740 Wp
295 W more power
Power density
200.3 Wp/m²
238.2 Wp/m²
37.9 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
24.5 kg
38.2 kg
13.7 kg lighter
Short-circuit current
11.32 A
18.73 A
7.41 A apart
Module area
2.222 m²
3.106 m²
0.885 m² apart
Weight per kWp
55.1 kg/kWp
51.6 kg/kWp
3.4 kg/kWp lighter
Cell technology
PERC
TOPCon
PERC vs TOPCon
Current at max power
10.80 A
17.64 A
6.84 A apart
Cell count
144
132
12 cells apart
Bifacial
No
Yes
No vs Yes
Dimensions
2112x1052x35 mm
2384x1303x33 mm
2112x1052x35 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
JAM72S20-445/MR
14,422 kWh
JAM66D46-740/LB
24,828 kWh
Lifetime gap
10,406 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
JAM72S20-445/MR
JAM66D46-740/LB
Standard test conditions
25 °C
100.0% of rated power
445 W
740 W
Cool, bright day
40 °C
94.8% of rated power
422 W
708 W
Typical summer roof
55 °C
89.5% of rated power
398 W
676 W
Hot roof
70 °C
84.2% of rated power
375 W
643 W
03
Full specification
Parameter
JAM72S20-445/MR
JAM66D46-740/LB
Difference
Power and efficiency
Rated power
445 Wp
740 Wp
+295 W for JAM66D46-740/LB
Module efficiency
20.00 %
23.80 %
+3.80 pp for JAM66D46-740/LB
Power density
200.3 Wp/m²
238.2 Wp/m²
+37.9 Wp/m² for JAM66D46-740/LB
Open-circuit voltage
49.56 V
49.80 V
Effectively the same
Voltage at max power
41.21 V
41.96 V
Effectively the same
Short-circuit current
11.32 A
18.73 A
7.41 A apart
Current at max power
10.80 A
17.64 A
6.84 A apart
Temperature
Temperature coefficient
-0.350 %/°C
-0.290 %/°C
+0.060 %/°C for JAM66D46-740/LB
Mechanical
Dimensions
2112x1052x35 mm
2384x1303x33 mm
2112x1052x35 mm vs 2384x1303x33 mm
Module area
2.222 m²
3.106 m²
0.885 m² apart
Weight
24.5 kg
38.2 kg
-13.7 kg for JAM72S20-445/MR
Weight per kWp
55.1 kg/kWp
51.6 kg/kWp
-3.4 kg/kWp for JAM66D46-740/LB
Warranty and degradation
Product warranty
12 yrs
12 yrs
Same
Performance warranty
25 yrs
30 yrs
+5 yrs for JAM66D46-740/LB
Annual degradation
0.55 %/yr
0.40 %/yr
-0.15 %/yr for JAM66D46-740/LB
Technology
Cell technology
PERC
TOPCon
PERC vs TOPCon
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
144
132
12 cells apart
Bifacial
No
Yes
No vs Yes
04
14,005 panels
Against the whole database
Efficiency
#12,214
vs
#433
JAM66D46-740/LB leads by 11,781 places
Power density
#12,162
vs
#431
JAM66D46-740/LB leads by 11,731 places
Heat behaviour
#10,419
vs
#2,165
JAM66D46-740/LB leads by 8,254 places
Weight
#9,435
vs
#4,997
JAM66D46-740/LB leads by 4,438 places
Warranty
#9,798
vs
#21
JAM66D46-740/LB leads by 9,777 places
Overall
#11,694
vs
#185
JAM66D46-740/LB leads by 11,509 places
05
Open the full database
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The same specification on paper
06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: JA Solar JAM72S20-445/MR or JA Solar JAM66D46-740/LB?
According to our database: JA Solar JAM66D46-740/LB has higher module efficiency (23.80% vs 20.00%); 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 JAM72S20-445/MR and JA Solar JAM66D46-740/LB?
JA Solar JAM72S20-445/MR has a module efficiency of 20.00%, while JA Solar JAM66D46-740/LB is 23.80%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM72S20-445/MR use vs JA Solar JAM66D46-740/LB?
JA Solar JAM72S20-445/MR uses PERC cells; JA Solar JAM66D46-740/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 JAM72S20-445/MR and JA Solar JAM66D46-740/LB?
JA Solar JAM72S20-445/MR has a 25 years power warranty; JA Solar JAM66D46-740/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 JAM72S20-445/MR and JA Solar JAM66D46-740/LB bifacial panels?
JA Solar JAM66D46-740/LB is bifacial (captures light from both faces); JA Solar JAM72S20-445/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.