Skip to main content
JAM60S21-390/MR/1000V vs JAM66D46-735/LB 2 of 19 identical Swap Change panels

JA Solar JAM60S21-390/MR/1000V vs JA Solar JAM66D46-735/LB

JAM60S21-390/MR/1000V
390 Wp 21.00 % PERC
Open panel page Datasheet PDF
VS
JA Solar JAM66D46-735/LB
JAM66D46-735/LB
735 Wp 23.70 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

JAM66D46-735/LB leads on the differences that matter

The largest is module efficiency: 2.70 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 JAM60S21-390/MR/1000V JAM66D46-735/LB Difference
Module efficiency 21.00 % 23.70 % 2.70 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 209.6 Wp/m² 236.6 Wp/m² 27.0 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 18.8 kg 38.2 kg 19.4 kg lighter
Open-circuit voltage 41.94 V 49.60 V 7.66 V apart
Short-circuit current 11.58 A 18.70 A 7.12 A apart
Module area 1.861 m² 3.106 m² 1.245 m² apart
Weight per kWp 48.2 kg/kWp 52.0 kg/kWp 3.8 kg/kWp lighter
Cell technology PERC TOPCon PERC vs TOPCon
Voltage at max power 35.33 V 41.77 V 6.44 V apart
Current at max power 11.04 A 17.60 A 6.56 A apart
Cell count 120 132 12 cells apart
Bifacial No Yes No vs Yes
Dimensions 1769x1052x30 mm 2384x1303x33 mm 1769x1052x30 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
JAM60S21-390/MR/1000V
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 JAM60S21-390/MR/1000V 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 JAM60S21-390/MR/1000V JAM66D46-735/LB Difference
Power and efficiency
Rated power 390 Wp 735 Wp +345 W for JAM66D46-735/LB
Module efficiency 21.00 % 23.70 % +2.70 pp for JAM66D46-735/LB
Power density 209.6 Wp/m² 236.6 Wp/m² +27.0 Wp/m² for JAM66D46-735/LB
Open-circuit voltage 41.94 V 49.60 V 7.66 V apart
Voltage at max power 35.33 V 41.77 V 6.44 V apart
Short-circuit current 11.58 A 18.70 A 7.12 A apart
Current at max power 11.04 A 17.60 A 6.56 A apart
Temperature
Temperature coefficient -0.350 %/°C -0.290 %/°C +0.060 %/°C for JAM66D46-735/LB
Mechanical
Dimensions 1769x1052x30 mm 2384x1303x33 mm 1769x1052x30 mm vs 2384x1303x33 mm
Module area 1.861 m² 3.106 m² 1.245 m² apart
Weight 18.8 kg 38.2 kg -19.4 kg for JAM60S21-390/MR/1000V
Weight per kWp 48.2 kg/kWp 52.0 kg/kWp -3.8 kg/kWp for JAM60S21-390/MR/1000V
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 120 132 12 cells apart
Bifacial No Yes No vs Yes
04

Against the whole database

14,129 panels
Efficiency
#9,828 vs #549
JAM66D46-735/LB leads by 9,279 places
Power density
#10,005 vs #614
JAM66D46-735/LB leads by 9,391 places
Heat behaviour
#10,489 vs #2,220
JAM66D46-735/LB leads by 8,269 places
Weight
#2,106 vs #5,445
JAM60S21-390/MR/1000V leads by 3,339 places
Warranty
#9,912 vs #21
JAM66D46-735/LB leads by 9,891 places
Overall
#12,055 vs #234
JAM66D46-735/LB leads by 11,821 places
05

More useful comparisons

Open the full database
Same series, other bin
JA Solar JAM60S21-390/MR/1000V vs JA Solar JAM60S21-385/MR/1000V
One difference: module efficiency
Same series, other bin
JA Solar JAM60S21-390/MR/1000V vs JA Solar JAM60S21-380/MR/1000V
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM60S21-390/MR/1000V vs JA Solar JAM60S21-375/MR/1000V
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM60S21-390/MR/1000V vs JA Solar JAM60S21-370/MR/1000V
5 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM60S21-390/MR/1000V vs JA Solar JAM60S21-365/MR/1000V
5 differences, the largest is 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

07

Questions about this pairing

Which panel is better: JA Solar JAM60S21-390/MR/1000V or JA Solar JAM66D46-735/LB?
According to our database: JA Solar JAM66D46-735/LB has higher module efficiency (23.70% vs 21.00%); 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 JAM60S21-390/MR/1000V and JA Solar JAM66D46-735/LB?
JA Solar JAM60S21-390/MR/1000V has a module efficiency of 21.00%, 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 JAM60S21-390/MR/1000V use vs JA Solar JAM66D46-735/LB?
JA Solar JAM60S21-390/MR/1000V 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 JAM60S21-390/MR/1000V and JA Solar JAM66D46-735/LB?
JA Solar JAM60S21-390/MR/1000V 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 JAM60S21-390/MR/1000V and JA Solar JAM66D46-735/LB bifacial panels?
JA Solar JAM66D46-735/LB is bifacial (captures light from both faces); JA Solar JAM60S21-390/MR/1000V is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

Shop prices: See 330 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.