Tongwei TNC M10-78 Bifacial vs Tongwei TWMNF-66HD
VS
The verdict
TWMNF-66HD leads on the differences that matter
The largest is rated power: 80 W more power. 5 of 17 comparable parameters are identical, with 2 more left out because at least one datasheet does not publish them.
See all 12 differencesHow alike are they
5
of 17 comparable
parameters are identical
parameters are identical
identical
differs
not published
01
12 of 17 parameters
What actually differs
Parameter
TNC M10-78 Bifacial
TWMNF-66HD
Difference
Rated power
635 Wp
715 Wp
80 W more power
Weight
33.8 kg
37.9 kg
4.1 kg lighter
Product warranty
12 yrs
15 yrs
3 yrs longer
Open-circuit voltage
57.20 V
49.11 V
8.09 V apart
Short-circuit current
13.82 A
18.50 A
4.68 A apart
Module area
2.795 m²
3.106 m²
0.311 m² apart
Module efficiency
22.70 %
23.00 %
0.30 pp more efficient
Power density
227.2 Wp/m²
230.2 Wp/m²
3.0 Wp/m² higher
Voltage at max power
48.05 V
40.86 V
7.19 V apart
Current at max power
13.22 A
17.50 A
4.28 A apart
Bifacial
No
Yes
No vs Yes
Dimensions
2465x1134 mm
2384x1303x33 mm
2465x1134 mm vs 2384x1303x33 mm
02
What it means on a roof
Thirty years of production
A 1.0% first-year loss then 0.40% a year, 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.
TNC M10-78 Bifacial
21,306 kWh
TWMNF-66HD
23,990 kWh
Lifetime gap
2,684 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
TNC M10-78 Bifacial
TWMNF-66HD
Standard test conditions
25 °C
100.0% of rated power
635 W
715 W
Cool, bright day
40 °C
95.8% of rated power
608 W
685 W
Typical summer roof
55 °C
91.6% of rated power
582 W
655 W
Hot roof
70 °C
87.4% of rated power
555 W
625 W
03
Full specification
Parameter
TNC M10-78 Bifacial
TWMNF-66HD
Difference
Power and efficiency
Rated power
635 Wp
715 Wp
+80 W for TWMNF-66HD
Module efficiency
22.70 %
23.00 %
+0.30 pp for TWMNF-66HD
Power density
227.2 Wp/m²
230.2 Wp/m²
+3.0 Wp/m² for TWMNF-66HD
Open-circuit voltage
57.20 V
49.11 V
8.09 V apart
Voltage at max power
48.05 V
40.86 V
7.19 V apart
Short-circuit current
13.82 A
18.50 A
4.68 A apart
Current at max power
13.22 A
17.50 A
4.28 A apart
Temperature
Temperature coefficient
-0.280 %/°C
-0.280 %/°C
Same
Mechanical
Dimensions
2465x1134 mm
2384x1303x33 mm
2465x1134 mm vs 2384x1303x33 mm
Module area
2.795 m²
3.106 m²
0.311 m² apart
Weight
33.8 kg
37.9 kg
-4.1 kg for TNC M10-78 Bifacial
Weight per kWp
53.2 kg/kWp
53.0 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
15 yrs
+3 yrs for TWMNF-66HD
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
0.40 %/yr
-
Not published by Tongwei
Technology
Cell technology
TOPCon
TOPCon
Same
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
-
132
Not published by Tongwei
Bifacial
No
Yes
No vs Yes
04
14,005 panels
Against the whole database
Efficiency
#3,307
vs
#1,919
TWMNF-66HD leads by 1,388 places
Power density
#3,252
vs
#2,018
TWMNF-66HD leads by 1,234 places
Heat behaviour
#1,309
vs
#1,309
Tied - the same position in the database
Weight
#7,071
vs
#6,744
TWMNF-66HD leads by 327 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#2,385
vs
#450
TWMNF-66HD leads by 1,935 places
05
Open the full database
More useful comparisons
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Tongwei TNC M10-78 Bifacial vs Tongwei TNC G12-66 Bifacial
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Tongwei TNC M10-78 Bifacial vs Tongwei TWMNH-66HD
12 differences, the largest is weight
Same series, other bin
Tongwei TNC M10-78 Bifacial vs Tongwei TNC G12R-66 Monofacial
9 differences, the largest is open-circuit voltage
06
Written summary
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07
Questions about this pairing
Which panel is better: Tongwei TNC M10-78 Bifacial or Tongwei TWMNF-66HD?
According to our database: Tongwei TWMNF-66HD has higher module efficiency (23.00% vs 22.70%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Tongwei TNC M10-78 Bifacial and Tongwei TWMNF-66HD?
Tongwei TNC M10-78 Bifacial has a module efficiency of 22.70%, while Tongwei TWMNF-66HD is 23.00%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Tongwei TNC M10-78 Bifacial use vs Tongwei TWMNF-66HD?
Tongwei TNC M10-78 Bifacial uses TOPCon cells; Tongwei TWMNF-66HD 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 TNC M10-78 Bifacial and Tongwei TWMNF-66HD?
Tongwei TNC M10-78 Bifacial has a 30 years power warranty; Tongwei TWMNF-66HD 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 TNC M10-78 Bifacial and Tongwei TWMNF-66HD bifacial panels?
Tongwei TWMNF-66HD is bifacial (captures light from both faces); Tongwei TNC M10-78 Bifacial is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.
Shop prices: See 72 Tongwei 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.