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STP670S-D66/Wmh vs STP660S-D66/Wmh 16 of 19 identical Swap Change panels

Suntech STP670S-D66/Wmh vs Suntech STP660S-D66/Wmh

Suntech STP670S-D66/Wmh
STP670S-D66/Wmh
670 Wp 21.60 % TOPCon
Open panel page Datasheet PDF
VS
Suntech STP660S-D66/Wmh
STP660S-D66/Wmh
660 Wp 21.20 % TOPCon
Open panel page Datasheet PDF
The verdict

STP670S-D66/Wmh leads on the differences that matter

The largest is module efficiency: 0.40 pp more efficient. 16 of 19 comparable parameters are identical.

See all 3 differences
How alike are they
16 of 19 comparable
parameters are identical
identical differs
01

What actually differs

3 of 19 parameters
Parameter STP670S-D66/Wmh STP660S-D66/Wmh Difference
Module efficiency 21.60 % 21.20 % 0.40 pp more efficient
Power density 215.7 Wp/m² 212.5 Wp/m² 3.2 Wp/m² higher
Rated power 670 Wp 660 Wp 10 W more power
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 (-0.340 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
STP670S-D66/Wmh
21,714 kWh
STP660S-D66/Wmh
21,390 kWh
Lifetime gap
324 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario STP670S-D66/Wmh STP660S-D66/Wmh
Standard test conditions 25 °C 100.0% of rated power 670 W 660 W
Cool, bright day 40 °C 94.9% of rated power 636 W 626 W
Typical summer roof 55 °C 89.8% of rated power 602 W 593 W
Hot roof 70 °C 84.7% of rated power 567 W 559 W
03

Full specification

Parameter STP670S-D66/Wmh STP660S-D66/Wmh Difference
Power and efficiency
Rated power 670 Wp 660 Wp +10 W for STP670S-D66/Wmh
Module efficiency 21.60 % 21.20 % +0.40 pp for STP670S-D66/Wmh
Power density 215.7 Wp/m² 212.5 Wp/m² +3.2 Wp/m² for STP670S-D66/Wmh
Open-circuit voltage 46.45 V 46.05 V Effectively the same
Voltage at max power 38.45 V 38.05 V Effectively the same
Short-circuit current 18.43 A 18.35 A Effectively the same
Current at max power 17.43 A 17.35 A Effectively the same
Temperature
Temperature coefficient -0.340 %/°C -0.340 %/°C Same
Mechanical
Dimensions 2384x1303x35 mm 2384x1303x35 mm Same
Module area 3.106 m² 3.106 m² Same
Weight 33.5 kg 33.5 kg Same
Weight per kWp 50.0 kg/kWp 50.8 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 25 yrs 25 yrs Same
Annual degradation 0.55 %/yr 0.55 %/yr Same
Technology
Cell technology TOPCon TOPCon Same
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial No No Same
04

Against the whole database

14,005 panels
Efficiency
#7,652 vs #9,076
STP670S-D66/Wmh leads by 1,424 places
Power density
#7,644 vs #8,959
STP670S-D66/Wmh leads by 1,315 places
Heat behaviour
#8,778 vs #8,778
Tied - the same position in the database
Weight
#3,317 vs #4,172
STP670S-D66/Wmh leads by 855 places
Warranty
#9,798 vs #9,798
Tied - the same position in the database
Overall
#3,364 vs #4,193
STP670S-D66/Wmh leads by 829 places
05

More useful comparisons

Open the full database
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Suntech STP670S-D66/Wmh vs Suntech STP670S-D66/Pmh+
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Suntech STP670S-D66/Wmh vs Suntech STP665S-D66/Wmh
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Suntech STP670S-D66/Wmh vs Suntech STP665S-D66/Pmh+
7 differences, the largest is performance warranty
Same series, other bin
Suntech STP670S-D66/Wmh vs Suntech STP660S-D66/Pmh+
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06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP670S-D66/Wmh or Suntech STP660S-D66/Wmh?
According to our database: Suntech STP670S-D66/Wmh has higher module efficiency (21.60% vs 21.20%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Suntech STP670S-D66/Wmh and Suntech STP660S-D66/Wmh?
Suntech STP670S-D66/Wmh has a module efficiency of 21.60%, while Suntech STP660S-D66/Wmh is 21.20%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Suntech STP670S-D66/Wmh use vs Suntech STP660S-D66/Wmh?
Suntech STP670S-D66/Wmh uses TOPCon cells; Suntech STP660S-D66/Wmh 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 STP670S-D66/Wmh and Suntech STP660S-D66/Wmh?
Suntech STP670S-D66/Wmh has a 25 years power warranty; Suntech STP660S-D66/Wmh has a 25 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.

Shop prices: See 22 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.