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HT72-18X 540W vs HT66-210(ND)-F 705W 3 of 18 identical Swap Change panels

HT-SAAE HT72-18X 540W vs HT-SAAE HT66-210(ND)-F 705W

HT-SAAE
HT72-18X 540W
540 Wp 20.90 % PERC Incomplete
VS
HT-SAAE HT66-210(ND)-F 705W
HT-SAAE
HT66-210(ND)-F 705W
705 Wp 22.70 % TOPCon Bifacial
The verdict

HT66-210(ND)-F 705W leads on the differences that matter

The largest is module efficiency: 1.80 pp more efficient. 3 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 15 differences
How alike are they
3 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

15 of 18 parameters
Parameter HT72-18X 540W HT66-210(ND)-F 705W Difference
Module efficiency 20.90 % 22.70 % 1.80 pp more efficient
Rated power 540 Wp 705 Wp 165 W more power
Power density 208.9 Wp/m² 227.0 Wp/m² 18.0 Wp/m² higher
Performance warranty 25 yrs 30 yrs 5 yrs longer
Weight 28.5 kg 38.5 kg 10.0 kg lighter
Product warranty 25 yrs 30 yrs 5 yrs longer
Temperature coefficient -0.330 %/°C -0.310 %/°C 0.020 %/°C better in heat
Short-circuit current 13.90 A 18.41 A 4.51 A apart
Module area 2.584 m² 3.106 m² 0.522 m² apart
Cell technology PERC TOPCon PERC vs TOPCon
Current at max power 12.97 A 17.16 A 4.19 A apart
Cell count 144 132 12 cells apart
Open-circuit voltage 49.50 V 48.00 V 1.50 V apart
Bifacial No Yes No vs Yes
Dimensions 2279x1134x35 mm 2384x1303x35 mm 2279x1134x35 mm vs 2384x1303x35 mm
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
HT72-18X 540W
17,826 kWh
HT66-210(ND)-F 705W
23,654 kWh
Lifetime gap
5,828 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario HT72-18X 540W HT66-210(ND)-F 705W
Standard test conditions 25 °C 100.0% of rated power 540 W 705 W
Cool, bright day 40 °C 95.0% of rated power 513 W 672 W
Typical summer roof 55 °C 90.1% of rated power 487 W 639 W
Hot roof 70 °C 85.2% of rated power 460 W 607 W
03

Full specification

Parameter HT72-18X 540W HT66-210(ND)-F 705W Difference
Power and efficiency
Rated power 540 Wp 705 Wp +165 W for HT66-210(ND)-F 705W
Module efficiency 20.90 % 22.70 % +1.80 pp for HT66-210(ND)-F 705W
Power density 208.9 Wp/m² 227.0 Wp/m² +18.0 Wp/m² for HT66-210(ND)-F 705W
Open-circuit voltage 49.50 V 48.00 V 1.50 V apart
Voltage at max power 41.65 V 41.10 V Effectively the same
Short-circuit current 13.90 A 18.41 A 4.51 A apart
Current at max power 12.97 A 17.16 A 4.19 A apart
Temperature
Temperature coefficient -0.330 %/°C -0.310 %/°C +0.020 %/°C for HT66-210(ND)-F 705W
Mechanical
Dimensions 2279x1134x35 mm 2384x1303x35 mm 2279x1134x35 mm vs 2384x1303x35 mm
Module area 2.584 m² 3.106 m² 0.522 m² apart
Weight 28.5 kg 38.5 kg -10.0 kg for HT72-18X 540W
Weight per kWp 52.8 kg/kWp 54.6 kg/kWp Effectively the same
Warranty and degradation
Product warranty 25 yrs 30 yrs +5 yrs for HT66-210(ND)-F 705W
Performance warranty 25 yrs 30 yrs +5 yrs for HT66-210(ND)-F 705W
Annual degradation - 0.40 %/yr Not published by HT-SAAE
Technology
Cell technology PERC TOPCon PERC vs TOPCon
Cell type Monocrystalline Monocrystalline Same
Cell count 144 132 12 cells apart
Bifacial No Yes No vs Yes
04

Against the whole database

14,129 panels
Efficiency
#10,148 vs #3,364
HT66-210(ND)-F 705W leads by 6,784 places
Power density
#10,278 vs #3,418
HT66-210(ND)-F 705W leads by 6,860 places
Heat behaviour
#8,613 vs #8,069
HT66-210(ND)-F 705W leads by 544 places
Weight
#6,505 vs #9,041
HT72-18X 540W leads by 2,536 places
Warranty
#9,912 vs #21
HT66-210(ND)-F 705W leads by 9,891 places
Overall
#6,034 vs #85
HT66-210(ND)-F 705W leads by 5,949 places
05

More useful comparisons

Open the full database
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HT-SAAE HT72-18X 540W vs HT-SAAE HT72-18X 560W
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HT-SAAE HT72-18X 540W vs HT-SAAE HT72-18X 555W
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HT-SAAE HT72-18X 540W vs HT-SAAE HT72-18X 550W
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HT-SAAE HT72-18X 540W vs HT-SAAE HT72-18X 545W
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HT-SAAE HT66-210(ND)-F 705W vs HT-SAAE HT66-210(ND)-F 715W
3 differences, the largest is module efficiency
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HT-SAAE HT66-210(ND)-F 705W vs HT-SAAE HT66-210(ND)-F 710W
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06

Written summary

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07

Questions about this pairing

Which panel is better: HT-SAAE HT72-18X 540W or HT-SAAE HT66-210(ND)-F 705W?
According to our database: HT-SAAE HT66-210(ND)-F 705 W has higher module efficiency (22.70% vs 20.90%); HT-SAAE HT66-210(ND)-F 705 W tolerates heat better (temp coeff -0.310%/°C vs -0.330%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of HT-SAAE HT72-18X 540W and HT-SAAE HT66-210(ND)-F 705W?
HT-SAAE HT72-18X 540 W has a module efficiency of 20.90%, while HT-SAAE HT66-210(ND)-F 705 W is 22.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does HT-SAAE HT72-18X 540W use vs HT-SAAE HT66-210(ND)-F 705W?
HT-SAAE HT72-18X 540 W uses PERC cells; HT-SAAE HT66-210(ND)-F 705 W 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 HT-SAAE HT72-18X 540W and HT-SAAE HT66-210(ND)-F 705W?
HT-SAAE HT72-18X 540 W has a 25 years power warranty; HT-SAAE HT66-210(ND)-F 705 W 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 HT-SAAE HT72-18X 540W and HT-SAAE HT66-210(ND)-F 705W bifacial panels?
HT-SAAE HT66-210(ND)-F 705 W is bifacial (captures light from both faces); HT-SAAE HT72-18X 540 W is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

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.