Tongwei TWMHF-66HD740X vs Tongwei TWMNH-66HD645
VS
The verdict
TWMHF-66HD740X leads on the differences that matter
The largest is temperature coefficient: 0.040 %/°C better in heat. 11 of 19 comparable parameters are identical.
See all 8 differencesHow alike are they
11
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
8 of 19 parameters
What actually differs
Parameter
TWMHF-66HD740X
TWMNH-66HD645
Difference
Temperature coefficient
-0.240 %/°C
-0.280 %/°C
0.040 %/°C better in heat
Rated power
740 Wp
645 Wp
95 W more power
Weight
37.0 kg
32.2 kg
4.8 kg lighter
Product warranty
15 yrs
12 yrs
3 yrs longer
Short-circuit current
18.47 A
16.39 A
2.08 A apart
Module area
3.106 m²
2.701 m²
0.405 m² apart
Current at max power
17.49 A
15.54 A
1.95 A apart
Dimensions
2384x1303x33 mm
2382x1134x30 mm
2384x1303x33 mm vs 2382x1134x30 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
TWMHF-66HD740X
24,925 kWh
TWMNH-66HD645
21,641 kWh
Lifetime gap
3,284 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
TWMHF-66HD740X
TWMNH-66HD645
Standard test conditions
25 °C
100.0% of rated power
740 W
645 W
Cool, bright day
40 °C
95.8% of rated power
713 W
618 W
Typical summer roof
55 °C
91.6% of rated power
687 W
591 W
Hot roof
70 °C
87.4% of rated power
660 W
564 W
03
Full specification
Parameter
TWMHF-66HD740X
TWMNH-66HD645
Difference
Power and efficiency
Rated power
740 Wp
645 Wp
+95 W for TWMHF-66HD740X
Module efficiency
23.80 %
23.90 %
Effectively the same
Power density
238.2 Wp/m²
238.8 Wp/m²
Effectively the same
Open-circuit voltage
50.62 V
49.85 V
Effectively the same
Voltage at max power
42.32 V
41.51 V
Effectively the same
Short-circuit current
18.47 A
16.39 A
2.08 A apart
Current at max power
17.49 A
15.54 A
1.95 A apart
Temperature
Temperature coefficient
-0.240 %/°C
-0.280 %/°C
+0.040 %/°C for TWMHF-66HD740X
Mechanical
Dimensions
2384x1303x33 mm
2382x1134x30 mm
2384x1303x33 mm vs 2382x1134x30 mm
Module area
3.106 m²
2.701 m²
0.405 m² apart
Weight
37.0 kg
32.2 kg
-4.8 kg for TWMNH-66HD645
Weight per kWp
50.0 kg/kWp
49.9 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
15 yrs
12 yrs
+3 yrs for TWMHF-66HD740X
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
0.38 %/yr
0.40 %/yr
Effectively the same
Technology
Cell technology
N-type
N-type
Same
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
132
132
Same
Bifacial
Yes
Yes
Same
04
14,005 panels
Against the whole database
Efficiency
#433
vs
#351
TWMNH-66HD645 leads by 82 places
Power density
#431
vs
#356
TWMNH-66HD645 leads by 75 places
Heat behaviour
#13
vs
#1,309
TWMHF-66HD740X leads by 1,296 places
Weight
#3,317
vs
#3,293
TWMNH-66HD645 leads by 24 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#130
vs
#1,342
TWMHF-66HD740X leads by 1,212 places
05
Open the full database
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06
Written summary
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07
Questions about this pairing
Which panel is better: Tongwei TWMHF-66HD740X or Tongwei TWMNH-66HD645?
According to our database: Tongwei TWMNH-66HD645 has higher module efficiency (23.90% vs 23.80%); Tongwei TWMHF-66HD740X tolerates heat better (temp coeff -0.240%/°C vs -0.280%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Tongwei TWMHF-66HD740X and Tongwei TWMNH-66HD645?
Tongwei TWMHF-66HD740X has a module efficiency of 23.80%, while Tongwei TWMNH-66HD645 is 23.90%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Tongwei TWMHF-66HD740X use vs Tongwei TWMNH-66HD645?
Tongwei TWMHF-66HD740X uses N-type cells; Tongwei TWMNH-66HD645 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 TWMHF-66HD740X and Tongwei TWMNH-66HD645?
Tongwei TWMHF-66HD740X has a 30 years power warranty; Tongwei TWMNH-66HD645 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 TWMHF-66HD740X and Tongwei TWMNH-66HD645 bifacial panels?
Both Tongwei TWMHF-66HD740X and Tongwei TWMNH-66HD645 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.