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615/MB/1500V vs 620/MB/1500V 18 of 19 identical Swap Change panels

JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM78D40-620/MB/1500V

JAM78D40-615/MB/1500V
615 Wp 22.00 % N-type Bifacial
Open panel page Datasheet PDF
VS
JAM78D40-620/MB/1500V
620 Wp 22.20 % N-type Bifacial
Open panel page Datasheet PDF
The verdict

620/MB/1500V leads on the differences that matter

The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical.

See the one difference
How alike are they
18 of 19 comparable
parameters are identical
identical differs
01

What actually differs

1 of 19 parameters
Parameter 615/MB/1500V 620/MB/1500V Difference
Module efficiency 22.00 % 22.20 % 0.20 pp more efficient
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
Same temp coeff. for both panels (-0.300 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
615/MB/1500V
20,634 kWh
620/MB/1500V
20,802 kWh
Lifetime gap
168 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 615/MB/1500V 620/MB/1500V
Standard test conditions 25 °C 100.0% of rated power 615 W 620 W
Cool, bright day 40 °C 95.5% of rated power 587 W 592 W
Typical summer roof 55 °C 91.0% of rated power 560 W 564 W
Hot roof 70 °C 86.5% of rated power 532 W 536 W
03

Full specification

Parameter 615/MB/1500V 620/MB/1500V Difference
Power and efficiency
Rated power 615 Wp 620 Wp Effectively the same
Module efficiency 22.00 % 22.20 % +0.20 pp for 620/MB/1500V
Power density 220.0 Wp/m² 221.8 Wp/m² Effectively the same
Open-circuit voltage 55.20 V 55.34 V Effectively the same
Voltage at max power 46.07 V 46.20 V Effectively the same
Short-circuit current 14.23 A 14.30 A Effectively the same
Current at max power 13.35 A 13.42 A Effectively the same
Temperature
Temperature coefficient -0.300 %/°C -0.300 %/°C Same
Mechanical
Dimensions 2465x1134x35 mm 2465x1134x35 mm Same
Module area 2.795 m² 2.795 m² Same
Weight 34.6 kg 34.6 kg Same
Weight per kWp 56.3 kg/kWp 55.8 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/yr 0.40 %/yr Same
Technology
Cell technology N-type N-type Same
Cell type Monocrystalline Monocrystalline Same
Cell count 156 156 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#6,517 vs #5,817
620/MB/1500V leads by 700 places
Power density
#6,655 vs #5,869
620/MB/1500V leads by 786 places
Heat behaviour
#6,093 vs #6,093
Tied - the same position in the database
Weight
#10,534 vs #10,192
620/MB/1500V leads by 342 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#3,865 vs #3,457
620/MB/1500V leads by 408 places
05

More useful comparisons

Open the full database
Same series, other bin
JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM78D40-625/MB/1500V
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM78D40-610/MB/1500V
One difference: module efficiency
Same series, other bin
JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM78D40-605/MB/1500V
3 differences, the largest is module efficiency
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JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM78D40-600/MB/1500V
3 differences, the largest is module efficiency
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JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM66D46-740/LB
14 differences, the largest is module efficiency
Same manufacturer
JA Solar JAM78D40-615/MB/1500V vs JA Solar JAM66D46-735/LB
14 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: JA Solar JAM78D40-615/MB/1500V or JA Solar JAM78D40-620/MB/1500V?
According to our database: JA Solar JAM78D40-620/MB/1500V has higher module efficiency (22.20% vs 22.00%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM78D40-615/MB/1500V and JA Solar JAM78D40-620/MB/1500V?
JA Solar JAM78D40-615/MB/1500V has a module efficiency of 22.00%, while JA Solar JAM78D40-620/MB/1500V is 22.20%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM78D40-615/MB/1500V use vs JA Solar JAM78D40-620/MB/1500V?
JA Solar JAM78D40-615/MB/1500V uses N-type cells; JA Solar JAM78D40-620/MB/1500V uses N-type. 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 JAM78D40-615/MB/1500V and JA Solar JAM78D40-620/MB/1500V?
JA Solar JAM78D40-615/MB/1500V has a 30 years power warranty; JA Solar JAM78D40-620/MB/1500V 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 JAM78D40-615/MB/1500V and JA Solar JAM78D40-620/MB/1500V bifacial panels?
Both JA Solar JAM78D40-615/MB/1500V and JA Solar JAM78D40-620/MB/1500V are bifacial - they capture reflected light from the ground, which can add 5-15% more annual energy on ground-mount or elevated rooftop installations with a light surface beneath.

Shop prices: See 393 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.