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54HD vs 66HD 12 of 18 identical Swap Change panels

Tongwei TWMNH-54HD vs Tongwei TWMNH-66HD

TWMNH-54HD
515 Wp 19.07 % TOPCon Bifacial Incomplete
Open panel page Datasheet PDF
VS
TWMNH-66HD
620 Wp 22.95 % TOPCon Bifacial Incomplete
Open panel page Datasheet PDF
The verdict

66HD leads on the differences that matter

The largest is module efficiency: 3.88 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 54HD 66HD Difference
Module efficiency 19.07 % 22.95 % 3.88 pp more efficient
Rated power 515 Wp 620 Wp 105 W more power
Power density 190.7 Wp/m² 229.5 Wp/m² 38.9 Wp/m² higher
Weight per kWp 56.3 kg/kWp 46.8 kg/kWp 9.5 kg/kWp lighter
Open-circuit voltage 40.60 V 49.10 V 8.50 V apart
Voltage at max power 34.43 V 40.82 V 6.39 V apart
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.
54HD
17,279 kWh
66HD
20,802 kWh
Lifetime gap
3,523 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 54HD 66HD
Standard test conditions 25 °C 100.0% of rated power 515 W 620 W
Cool, bright day 40 °C 95.8% of rated power 493 W 594 W
Typical summer roof 55 °C 91.6% of rated power 472 W 568 W
Hot roof 70 °C 87.4% of rated power 450 W 542 W
03

Full specification

Parameter 54HD 66HD Difference
Power and efficiency
Rated power 515 Wp 620 Wp +105 W for 66HD
Module efficiency 19.07 % 22.95 % +3.88 pp for 66HD
Power density 190.7 Wp/m² 229.5 Wp/m² +38.9 Wp/m² for 66HD
Open-circuit voltage 40.60 V 49.10 V 8.50 V apart
Voltage at max power 34.43 V 40.82 V 6.39 V apart
Short-circuit current 15.98 A 16.06 A Effectively the same
Current at max power 14.96 A 15.19 A Effectively the same
Temperature
Temperature coefficient -0.280 %/°C -0.280 %/°C Same
Mechanical
Dimensions 2382x1134x30 mm 2382x1134x30 mm Same
Module area 2.701 m² 2.701 m² Same
Weight 29.0 kg 29.0 kg Same
Weight per kWp 56.3 kg/kWp 46.8 kg/kWp -9.5 kg/kWp for 66HD
Warranty and degradation
Product warranty 15 yrs 15 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation - - Neither datasheet publishes this
Technology
Cell technology TOPCon TOPCon Same
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#12,923 vs #2,268
66HD leads by 10,655 places
Power density
#12,908 vs #2,191
66HD leads by 10,717 places
Heat behaviour
#1,309 vs #1,309
Tied - the same position in the database
Weight
#10,565 vs #1,343
66HD leads by 9,222 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#9,980 vs #2,013
66HD leads by 7,967 places
05

More useful comparisons

Open the full database
Same series, other bin
Tongwei TWMNH-54HD vs Tongwei THC G12-66 Bifacial
11 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNH-54HD vs Tongwei TWMNF-66HD
11 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNH-54HD vs Tongwei TWMNH-66HS
6 differences, the largest is module efficiency
Same series, other bin
Tongwei TWMNH-54HD vs Tongwei TWMNH-48HC
6 differences, the largest is module efficiency
Same manufacturer
Tongwei TWMNH-54HD vs Tongwei TWMNF-66HD750
12 differences, the largest is module efficiency
Same manufacturer
Tongwei TWMNH-54HD vs Tongwei TWMNF-66HD745
12 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Tongwei TWMNH-54HD or Tongwei TWMNH-66HD?
According to our database: Tongwei TWMNH-66HD has higher module efficiency (22.95% vs 19.07%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Tongwei TWMNH-54HD and Tongwei TWMNH-66HD?
Tongwei TWMNH-54HD has a module efficiency of 19.07%, while Tongwei TWMNH-66HD is 22.95%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Tongwei TWMNH-54HD use vs Tongwei TWMNH-66HD?
Tongwei TWMNH-54HD uses TOPCon cells; Tongwei TWMNH-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 TWMNH-54HD and Tongwei TWMNH-66HD?
Tongwei TWMNH-54HD has a 30 years power warranty; Tongwei TWMNH-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 TWMNH-54HD and Tongwei TWMNH-66HD bifacial panels?
Both Tongwei TWMNH-54HD and Tongwei TWMNH-66HD 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.