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STP720S-D66-Nsh+ vs STP635S-H66-Nsh+ 11 of 19 identical Swap Change panels

Suntech STP720S-D66-Nsh+ vs Suntech STP635S-H66-Nsh+

Suntech STP720S-D66-Nsh+
STP720S-D66-Nsh+
720 Wp 23.20 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Suntech STP635S-H66-Nsh+
STP635S-H66-Nsh+
635 Wp 23.50 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

8 differences, and they point both ways

The largest is rated power: 85 W more power. 11 of 19 comparable parameters are identical.

See all 8 differences
How alike are they
11 of 19 comparable
parameters are identical
identical differs
01

What actually differs

8 of 19 parameters
Parameter STP720S-D66-Nsh+ STP635S-H66-Nsh+ Difference
Rated power 720 Wp 635 Wp 85 W more power
Weight 37.5 kg 33.1 kg 4.4 kg lighter
Short-circuit current 18.46 A 16.08 A 2.38 A apart
Module area 3.106 m² 2.701 m² 0.405 m² apart
Module efficiency 23.20 % 23.50 % 0.30 pp more efficient
Power density 231.8 Wp/m² 235.1 Wp/m² 3.3 Wp/m² higher
Current at max power 17.62 A 15.31 A 2.31 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
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.
STP720S-D66-Nsh+
24,157 kWh
STP635S-H66-Nsh+
21,306 kWh
Lifetime gap
2,851 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario STP720S-D66-Nsh+ STP635S-H66-Nsh+
Standard test conditions 25 °C 100.0% of rated power 720 W 635 W
Cool, bright day 40 °C 95.8% of rated power 690 W 608 W
Typical summer roof 55 °C 91.6% of rated power 660 W 582 W
Hot roof 70 °C 87.4% of rated power 629 W 555 W
03

Full specification

Parameter STP720S-D66-Nsh+ STP635S-H66-Nsh+ Difference
Power and efficiency
Rated power 720 Wp 635 Wp +85 W for STP720S-D66-Nsh+
Module efficiency 23.20 % 23.50 % +0.30 pp for STP635S-H66-Nsh+
Power density 231.8 Wp/m² 235.1 Wp/m² +3.3 Wp/m² for STP635S-H66-Nsh+
Open-circuit voltage 49.26 V 49.50 V Effectively the same
Voltage at max power 40.87 V 41.50 V Effectively the same
Short-circuit current 18.46 A 16.08 A 2.38 A apart
Current at max power 17.62 A 15.31 A 2.31 A apart
Temperature
Temperature coefficient -0.280 %/°C -0.280 %/°C Same
Mechanical
Dimensions 2384x1303x33 mm 2382x1134x30 mm 2384x1303x33 mm vs 2382x1134x30 mm
Module area 3.106 m² 2.701 m² 0.405 m² apart
Weight 37.5 kg 33.1 kg -4.4 kg for STP635S-H66-Nsh+
Weight per kWp 52.1 kg/kWp 52.1 kg/kWp Same
Warranty and degradation
Product warranty 15 yrs 15 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/yr 0.40 %/yr Same
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
#1,306 vs #716
STP635S-H66-Nsh+ leads by 590 places
Power density
#1,347 vs #741
STP635S-H66-Nsh+ leads by 606 places
Heat behaviour
#1,309 vs #1,309
Tied - the same position in the database
Weight
#5,516 vs #5,600
STP720S-D66-Nsh+ leads by 84 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#330 vs #1,462
STP720S-D66-Nsh+ leads by 1,132 places
05

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06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP720S-D66-Nsh+ or Suntech STP635S-H66-Nsh+?
According to our database: Suntech STP635S-H66-Nsh+ has higher module efficiency (23.50% vs 23.20%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Suntech STP720S-D66-Nsh+ and Suntech STP635S-H66-Nsh+?
Suntech STP720S-D66-Nsh+ has a module efficiency of 23.20%, while Suntech STP635S-H66-Nsh+ is 23.50%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Suntech STP720S-D66-Nsh+ use vs Suntech STP635S-H66-Nsh+?
Suntech STP720S-D66-Nsh+ uses TOPCon cells; Suntech STP635S-H66-Nsh+ 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 Suntech STP720S-D66-Nsh+ and Suntech STP635S-H66-Nsh+?
Suntech STP720S-D66-Nsh+ has a 30 years power warranty; Suntech STP635S-H66-Nsh+ 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 Suntech STP720S-D66-Nsh+ and Suntech STP635S-H66-Nsh+ bifacial panels?
Both Suntech STP720S-D66-Nsh+ and Suntech STP635S-H66-Nsh+ 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.

Shop prices: See 30 Suntech 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.