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JAM54S30-405/MR vs JAM66D46-740/LB 2 of 19 identical Swap Change panels

JA Solar JAM54S30-405/MR vs JA Solar JAM66D46-740/LB

JA Solar JAM54S30-405/MR
JAM54S30-405/MR
405 Wp 20.70 % PERC
Open panel page Datasheet PDF
VS
JA Solar JAM66D46-740/LB
JAM66D46-740/LB
740 Wp 23.80 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

JAM66D46-740/LB leads on the differences that matter

The largest is module efficiency: 3.10 pp more efficient. 2 of 19 comparable parameters are identical.

See all 17 differences
How alike are they
2 of 19 comparable
parameters are identical
identical differs
01

What actually differs

17 of 19 parameters
Parameter JAM54S30-405/MR JAM66D46-740/LB Difference
Module efficiency 20.70 % 23.80 % 3.10 pp more efficient
Temperature coefficient -0.350 %/°C -0.290 %/°C 0.060 %/°C better in heat
Rated power 405 Wp 740 Wp 335 W more power
Power density 207.4 Wp/m² 238.2 Wp/m² 30.8 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 37.23 V 49.80 V 12.57 V apart
Short-circuit current 13.87 A 18.73 A 4.86 A apart
Module area 1.953 m² 3.106 m² 1.154 m² apart
Weight per kWp 48.1 kg/kWp 51.6 kg/kWp 3.5 kg/kWp lighter
Cell technology PERC TOPCon PERC vs TOPCon
Voltage at max power 31.21 V 41.96 V 10.75 V apart
Current at max power 12.98 A 17.64 A 4.66 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
JAM54S30-405/MR
13,126 kWh
JAM66D46-740/LB
24,828 kWh
Lifetime gap
11,702 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario JAM54S30-405/MR JAM66D46-740/LB
Standard test conditions 25 °C 100.0% of rated power 405 W 740 W
Cool, bright day 40 °C 94.8% of rated power 384 W 708 W
Typical summer roof 55 °C 89.5% of rated power 362 W 676 W
Hot roof 70 °C 84.2% of rated power 341 W 643 W
03

Full specification

Parameter JAM54S30-405/MR JAM66D46-740/LB Difference
Power and efficiency
Rated power 405 Wp 740 Wp +335 W for JAM66D46-740/LB
Module efficiency 20.70 % 23.80 % +3.10 pp for JAM66D46-740/LB
Power density 207.4 Wp/m² 238.2 Wp/m² +30.8 Wp/m² for JAM66D46-740/LB
Open-circuit voltage 37.23 V 49.80 V 12.57 V apart
Voltage at max power 31.21 V 41.96 V 10.75 V apart
Short-circuit current 13.87 A 18.73 A 4.86 A apart
Current at max power 12.98 A 17.64 A 4.66 A apart
Temperature
Temperature coefficient -0.350 %/°C -0.290 %/°C +0.060 %/°C for JAM66D46-740/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 JAM54S30-405/MR
Weight per kWp 48.1 kg/kWp 51.6 kg/kWp -3.5 kg/kWp for JAM54S30-405/MR
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 108 132 24 cells apart
Bifacial No Yes No vs Yes
04

Against the whole database

14,005 panels
Efficiency
#10,764 vs #433
JAM66D46-740/LB leads by 10,331 places
Power density
#10,626 vs #431
JAM66D46-740/LB leads by 10,195 places
Heat behaviour
#10,419 vs #2,165
JAM66D46-740/LB leads by 8,254 places
Weight
#2,073 vs #4,997
JAM54S30-405/MR leads by 2,924 places
Warranty
#9,798 vs #21
JAM66D46-740/LB leads by 9,777 places
Overall
#11,881 vs #185
JAM66D46-740/LB leads by 11,696 places
05

More useful comparisons

Open the full database
Same series, other bin
JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-415/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-410/MR
One difference: module efficiency
Same series, other bin
JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-400/MR
One difference: module efficiency
Same series, other bin
JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-395/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-390/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM66D46-740/LB vs JA Solar JAM66D46-735/LB
The same specification on paper
06

Written summary

07

Questions about this pairing

Which panel is better: JA Solar JAM54S30-405/MR or JA Solar JAM66D46-740/LB?
According to our database: JA Solar JAM66D46-740/LB has higher module efficiency (23.80% vs 20.70%); 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 JAM54S30-405/MR and JA Solar JAM66D46-740/LB?
JA Solar JAM54S30-405/MR has a module efficiency of 20.70%, 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 JAM54S30-405/MR use vs JA Solar JAM66D46-740/LB?
JA Solar JAM54S30-405/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 JAM54S30-405/MR and JA Solar JAM66D46-740/LB?
JA Solar JAM54S30-405/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 JAM54S30-405/MR and JA Solar JAM66D46-740/LB bifacial panels?
JA Solar JAM66D46-740/LB is bifacial (captures light from both faces); JA Solar JAM54S30-405/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.