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66HD715XX vs 66HD740 12 of 18 identical Swap Change panels

Tongwei TWMNF-66HD715XX vs Tongwei TWMNF-66HD740

TWMNF-66HD715XX
715 Wp 23.00 % N-type Bifacial Incomplete
Open panel page Datasheet PDF
VS
Tongwei TWMNF-66HD740
TWMNF-66HD740
740 Wp 23.80 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

66HD740 leads on the differences that matter

The largest is module efficiency: 0.80 pp more efficient. 12 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 6 differences
How alike are they
12 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

6 of 18 parameters
Parameter 66HD715XX 66HD740 Difference
Module efficiency 23.00 % 23.80 % 0.80 pp more efficient
Power density 230.2 Wp/m² 238.2 Wp/m² 8.0 Wp/m² higher
Rated power 715 Wp 740 Wp 25 W more power
Cell technology N-type TOPCon N-type vs TOPCon
Weight per kWp 53.0 kg/kWp 50.4 kg/kWp 2.6 kg/kWp lighter
Voltage at max power 40.69 V 41.69 V 1.00 V apart
02

What it means on a roof

Thirty years of production
Declared first-year losses, with 0.40% a year afterwards assumed for both panels, at 1,200 kWh/kWp a year
Same temp coeff. for both panels (-0.280 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
66HD715XX
23,990 kWh
66HD740
24,828 kWh
Lifetime gap
838 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 66HD715XX 66HD740
Standard test conditions 25 °C 100.0% of rated power 715 W 740 W
Cool, bright day 40 °C 95.8% of rated power 685 W 709 W
Typical summer roof 55 °C 91.6% of rated power 655 W 678 W
Hot roof 70 °C 87.4% of rated power 625 W 647 W
03

Full specification

Parameter 66HD715XX 66HD740 Difference
Power and efficiency
Rated power 715 Wp 740 Wp +25 W for 66HD740
Module efficiency 23.00 % 23.80 % +0.80 pp for 66HD740
Power density 230.2 Wp/m² 238.2 Wp/m² +8.0 Wp/m² for 66HD740
Open-circuit voltage 49.11 V 49.80 V Effectively the same
Voltage at max power 40.69 V 41.69 V 1.00 V apart
Short-circuit current 18.55 A 18.81 A Effectively the same
Current at max power 17.60 A 17.75 A Effectively the same
Temperature
Temperature coefficient -0.280 %/°C -0.280 %/°C Same
Mechanical
Dimensions 2384x1303x33 mm 2384x1303x33 mm Same
Module area 3.106 m² 3.106 m² Same
Weight 37.9 kg 37.3 kg Effectively the same
Weight per kWp 53.0 kg/kWp 50.4 kg/kWp -2.6 kg/kWp for 66HD740
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation - 0.40 %/yr Not published by Tongwei
Technology
Cell technology N-type TOPCon N-type vs TOPCon
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#1,919 vs #433
66HD740 leads by 1,486 places
Power density
#2,018 vs #431
66HD740 leads by 1,587 places
Heat behaviour
#1,309 vs #1,309
Tied - the same position in the database
Weight
#6,744 vs #3,784
66HD740 leads by 2,960 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#678 vs #183
66HD740 leads by 495 places
05

More useful comparisons

Open the full database
Same series, other bin
Tongwei TWMNF-66HD715XX vs Tongwei TWMNF-66HD720XX
One difference: module efficiency
Same series, other bin
Tongwei TWMNF-66HD715XX vs Tongwei TWMNF-66HD710XX
The same specification on paper
Same series, other bin
Tongwei TWMNF-66HD715XX vs Tongwei TWMNF-66HD705XX
3 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNF-66HD715XX vs Tongwei TWMNF-66HD700XX
3 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD750
3 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD745
One difference: module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Tongwei TWMNF-66HD715XX or Tongwei TWMNF-66HD740?
According to our database: Tongwei TWMNF-66HD740 has higher module efficiency (23.80% vs 23.00%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Tongwei TWMNF-66HD715XX and Tongwei TWMNF-66HD740?
Tongwei TWMNF-66HD715XX has a module efficiency of 23.00%, while Tongwei TWMNF-66HD740 is 23.80%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Tongwei TWMNF-66HD715XX use vs Tongwei TWMNF-66HD740?
Tongwei TWMNF-66HD715XX uses N-type cells; Tongwei TWMNF-66HD740 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 Tongwei TWMNF-66HD715XX and Tongwei TWMNF-66HD740?
Tongwei TWMNF-66HD715XX has a 30 years power warranty; Tongwei TWMNF-66HD740 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 Tongwei TWMNF-66HD715XX and Tongwei TWMNF-66HD740 bifacial panels?
Both Tongwei TWMNF-66HD715XX and Tongwei TWMNF-66HD740 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.

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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.