JAM66D46-735/LB vs JAM72S20-455/MR 5 of 19 identical Swap Change panels

JA Solar JAM66D46-735/LB vs JA Solar JAM72S20-455/MR

Q: Which panel is better: JA Solar JAM66D46-735/LB or JA Solar JAM72S20-455/MR?

According to our database: JA Solar JAM66D46-735/LB has higher module efficiency (23.70% vs 20.50%); 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.

Q: What is the efficiency of JA Solar JAM66D46-735/LB and JA Solar JAM72S20-455/MR?

JA Solar JAM66D46-735/LB has a module efficiency of 23.70%, while JA Solar JAM72S20-455/MR is 20.50%. Higher efficiency means more electricity from the same roof area - useful when space is limited.

Q: What cell technology does JA Solar JAM66D46-735/LB use vs JA Solar JAM72S20-455/MR?

JA Solar JAM66D46-735/LB uses TOPCon cells; JA Solar JAM72S20-455/MR uses PERC. Modern n-type technologies (TOPCon, HJT, BC) typically deliver higher efficiency and lower degradation compared to older PERC (p-type) cells.

Q: What is the warranty on JA Solar JAM66D46-735/LB and JA Solar JAM72S20-455/MR?

JA Solar JAM66D46-735/LB has a 30 years power warranty; JA Solar JAM72S20-455/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.

Q: Are JA Solar JAM66D46-735/LB and JA Solar JAM72S20-455/MR bifacial panels?

JA Solar JAM66D46-735/LB is bifacial (captures light from both faces); JA Solar JAM72S20-455/MR is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

JAM66D46-735/LB

735 Wp 23.70 % TOPCon Bifacial

Open panel page Datasheet PDF

JAM72S20-455/MR

455 Wp 20.50 % PERC

Open panel page Datasheet PDF

The verdict

JAM66D46-735/LB leads on the differences that matter

The largest is module efficiency: 3.20 pp more efficient. 5 of 19 comparable parameters are identical.

See all 14 differences

How alike are they

5 of 19 comparable
parameters are identical

identical differs

What actually differs

14 of 19 parameters

Parameter JAM66D46-735/LB JAM72S20-455/MR Difference

Module efficiency 23.70 % 20.50 % 3.20 pp more efficient

Temperature coefficient -0.290 %/°C -0.350 %/°C 0.060 %/°C better in heat

Rated power 735 Wp 455 Wp 280 W more power

Power density 236.6 Wp/m² 204.8 Wp/m² 31.8 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 18.70 A 11.41 A 7.29 A apart

Module area 3.106 m² 2.222 m² 0.885 m² apart

Cell technology TOPCon PERC TOPCon vs PERC

Current at max power 17.60 A 10.88 A 6.72 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

What it means on a roof

Thirty years of production

Each panel's own declared degradation curve, at 1,200 kWh/kWp a year

Cell temperature

JAM66D46-735/LB

24,661 kWh

JAM72S20-455/MR

14,746 kWh

Lifetime gap

9,915 kWh

Output when it is hot

Rated power carried across the range a module actually sees

Scenario JAM66D46-735/LB JAM72S20-455/MR

Standard test conditions 25 °C 100.0% of rated power 735 W 455 W

Cool, bright day 40 °C 94.8% of rated power 703 W 431 W

Typical summer roof 55 °C 89.5% of rated power 671 W 407 W

Hot roof 70 °C 84.2% of rated power 639 W 383 W

Full specification

Parameter JAM66D46-735/LB JAM72S20-455/MR Difference

Power and efficiency

Rated power 735 Wp 455 Wp +280 W for JAM66D46-735/LB

Module efficiency 23.70 % 20.50 % +3.20 pp for JAM66D46-735/LB

Power density 236.6 Wp/m² 204.8 Wp/m² +31.8 Wp/m² for JAM66D46-735/LB

Open-circuit voltage 49.60 V 49.85 V Effectively the same

Voltage at max power 41.77 V 41.82 V Effectively the same

Short-circuit current 18.70 A 11.41 A 7.29 A apart

Current at max power 17.60 A 10.88 A 6.72 A apart

Temperature

Temperature coefficient -0.290 %/°C -0.350 %/°C +0.060 %/°C for JAM66D46-735/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 JAM72S20-455/MR

Weight per kWp 52.0 kg/kWp 53.8 kg/kWp Effectively the same

Warranty and degradation

Product warranty 12 yrs 12 yrs Same

Performance warranty 30 yrs 25 yrs +5 yrs for JAM66D46-735/LB

Annual degradation 0.40 %/yr 0.55 %/yr -0.15 %/yr for JAM66D46-735/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

Against the whole database

14,005 panels

Efficiency

#517 vs #11,308

JAM66D46-735/LB leads by 10,791 places

Power density

#582 vs #11,472

JAM66D46-735/LB leads by 10,890 places

Heat behaviour

#2,165 vs #10,419

JAM66D46-735/LB leads by 8,254 places

Weight

#5,413 vs #7,897

JAM66D46-735/LB leads by 2,484 places

Warranty

#21 vs #9,798

JAM66D46-735/LB leads by 9,777 places

Overall

#233 vs #11,208

JAM66D46-735/LB leads by 10,975 places

More useful comparisons

Open the full database

Same series, other bin

JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-740/LB

The same specification on paper

Same series, other bin

JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-730/LB

One difference: module efficiency

Same series, other bin

JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-725/LB

3 differences, the largest is module efficiency

Same series, other bin

JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-720/LB

3 differences, the largest is module efficiency

Same series, other bin

JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-715/LB

3 differences, the largest is module efficiency

Same series, other bin

JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-710/LB

5 differences, the largest is module efficiency

Written summary

Checking cache...

Questions about this pairing

Which panel is better: JA Solar JAM66D46-735/LB or JA Solar JAM72S20-455/MR?

According to our database: JA Solar JAM66D46-735/LB has higher module efficiency (23.70% vs 20.50%); 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 JAM66D46-735/LB and JA Solar JAM72S20-455/MR?

JA Solar JAM66D46-735/LB has a module efficiency of 23.70%, while JA Solar JAM72S20-455/MR is 20.50%. Higher efficiency means more electricity from the same roof area - useful when space is limited.

What cell technology does JA Solar JAM66D46-735/LB use vs JA Solar JAM72S20-455/MR?

JA Solar JAM66D46-735/LB uses TOPCon cells; JA Solar JAM72S20-455/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 JAM66D46-735/LB and JA Solar JAM72S20-455/MR?

JA Solar JAM66D46-735/LB has a 30 years power warranty; JA Solar JAM72S20-455/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 JAM66D46-735/LB and JA Solar JAM72S20-455/MR bifacial panels?

JA Solar JAM66D46-735/LB is bifacial (captures light from both faces); JA Solar JAM72S20-455/MR is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

Shop prices: See 348 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.