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66HD740 vs 66HD705XX 11 of 18 identical Swap Change panels

Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD705XX

Tongwei TWMNF-66HD740
TWMNF-66HD740
740 Wp 23.80 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
TWMNF-66HD705XX
705 Wp 22.70 % N-type Bifacial Incomplete
Open panel page Datasheet PDF
The verdict

66HD740 leads on the differences that matter

The largest is module efficiency: 1.10 pp more efficient. 11 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 7 differences
How alike are they
11 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

7 of 18 parameters
Parameter 66HD740 66HD705XX Difference
Module efficiency 23.80 % 22.70 % 1.10 pp more efficient
Power density 238.2 Wp/m² 227.0 Wp/m² 11.3 Wp/m² higher
Rated power 740 Wp 705 Wp 35 W more power
Weight per kWp 50.4 kg/kWp 53.8 kg/kWp 3.4 kg/kWp lighter
Cell technology TOPCon N-type TOPCon vs N-type
Open-circuit voltage 49.80 V 48.71 V 1.09 V apart
Voltage at max power 41.69 V 40.52 V 1.17 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.
66HD740
24,828 kWh
66HD705XX
23,654 kWh
Lifetime gap
1,174 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 66HD740 66HD705XX
Standard test conditions 25 °C 100.0% of rated power 740 W 705 W
Cool, bright day 40 °C 95.8% of rated power 709 W 675 W
Typical summer roof 55 °C 91.6% of rated power 678 W 646 W
Hot roof 70 °C 87.4% of rated power 647 W 616 W
03

Full specification

Parameter 66HD740 66HD705XX Difference
Power and efficiency
Rated power 740 Wp 705 Wp +35 W for 66HD740
Module efficiency 23.80 % 22.70 % +1.10 pp for 66HD740
Power density 238.2 Wp/m² 227.0 Wp/m² +11.3 Wp/m² for 66HD740
Open-circuit voltage 49.80 V 48.71 V 1.09 V apart
Voltage at max power 41.69 V 40.52 V 1.17 V apart
Short-circuit current 18.81 A 18.56 A Effectively the same
Current at max power 17.75 A 17.60 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 37.3 kg 37.9 kg Effectively the same
Weight per kWp 50.4 kg/kWp 53.8 kg/kWp -3.4 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 TOPCon N-type TOPCon vs N-type
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#433 vs #3,307
66HD740 leads by 2,874 places
Power density
#431 vs #3,361
66HD740 leads by 2,930 places
Heat behaviour
#1,309 vs #1,309
Tied - the same position in the database
Weight
#3,784 vs #7,811
66HD740 leads by 4,027 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#183 vs #1,007
66HD740 leads by 824 places
05

More useful comparisons

Open the full database
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
Same series, other bin
Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD735
The same specification on paper
Same series, other bin
Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD730
3 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNF-66HD705XX vs Tongwei TWMNF-66HD720XX
3 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNF-66HD705XX vs Tongwei TWMNF-66HD715XX
3 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Tongwei TWMNF-66HD740 or Tongwei TWMNF-66HD705XX?
According to our database: Tongwei TWMNF-66HD740 has higher module efficiency (23.80% vs 22.70%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Tongwei TWMNF-66HD740 and Tongwei TWMNF-66HD705XX?
Tongwei TWMNF-66HD740 has a module efficiency of 23.80%, while Tongwei TWMNF-66HD705XX is 22.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Tongwei TWMNF-66HD740 use vs Tongwei TWMNF-66HD705XX?
Tongwei TWMNF-66HD740 uses TOPCon cells; Tongwei TWMNF-66HD705XX 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 Tongwei TWMNF-66HD740 and Tongwei TWMNF-66HD705XX?
Tongwei TWMNF-66HD740 has a 30 years power warranty; Tongwei TWMNF-66HD705XX 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-66HD740 and Tongwei TWMNF-66HD705XX bifacial panels?
Both Tongwei TWMNF-66HD740 and Tongwei TWMNF-66HD705XX 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.