Skip to main content
STP665S-D66/Wmh vs STP670S-D66/Wmh 18 of 19 identical Swap Change panels

Suntech STP665S-D66/Wmh vs Suntech STP670S-D66/Wmh

Suntech STP665S-D66/Wmh
STP665S-D66/Wmh
665 Wp 21.40 % TOPCon
Open panel page Datasheet PDF
VS
Suntech STP670S-D66/Wmh
STP670S-D66/Wmh
670 Wp 21.60 % TOPCon
Open panel page Datasheet PDF
The verdict

STP670S-D66/Wmh leads on the differences that matter

The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical.

See the one difference
How alike are they
18 of 19 comparable
parameters are identical
identical differs
01

What actually differs

1 of 19 parameters
Parameter STP665S-D66/Wmh STP670S-D66/Wmh Difference
Module efficiency 21.40 % 21.60 % 0.20 pp more efficient
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.
STP665S-D66/Wmh
21,552 kWh
STP670S-D66/Wmh
21,714 kWh
Lifetime gap
162 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario STP665S-D66/Wmh STP670S-D66/Wmh
Standard test conditions 25 °C 100.0% of rated power 665 W 670 W
Cool, bright day 40 °C 94.9% of rated power 631 W 636 W
Typical summer roof 55 °C 89.8% of rated power 597 W 602 W
Hot roof 70 °C 84.7% of rated power 563 W 567 W
03

Full specification

Parameter STP665S-D66/Wmh STP670S-D66/Wmh Difference
Power and efficiency
Rated power 665 Wp 670 Wp Effectively the same
Module efficiency 21.40 % 21.60 % +0.20 pp for STP670S-D66/Wmh
Power density 214.1 Wp/m² 215.7 Wp/m² Effectively the same
Open-circuit voltage 46.25 V 46.45 V Effectively the same
Voltage at max power 38.25 V 38.45 V Effectively the same
Short-circuit current 18.39 A 18.43 A Effectively the same
Current at max power 17.39 A 17.43 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 50.4 kg/kWp 50.0 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
#8,323 vs #7,652
STP670S-D66/Wmh leads by 671 places
Power density
#8,250 vs #7,644
STP670S-D66/Wmh leads by 606 places
Heat behaviour
#8,778 vs #8,778
Tied - the same position in the database
Weight
#3,742 vs #3,317
STP670S-D66/Wmh leads by 425 places
Warranty
#9,798 vs #9,798
Tied - the same position in the database
Overall
#3,792 vs #3,364
STP670S-D66/Wmh leads by 428 places
05

More useful comparisons

Open the full database
Same series, other bin
Suntech STP665S-D66/Wmh vs Suntech STP700S-D66-Nsh+
12 differences, the largest is module efficiency
Same series, other bin
Suntech STP665S-D66/Wmh vs Suntech STP675S-D66/Wmh
3 differences, the largest is module efficiency
Same series, other bin
Suntech STP665S-D66/Wmh vs Suntech STP670S-D66/Pmh+
7 differences, the largest is performance warranty
Same series, other bin
Suntech STP665S-D66/Wmh vs Suntech STP665S-D66/Pmh+
6 differences, the largest is performance warranty
Same series, other bin
Suntech STP665S-D66/Wmh vs Suntech STP660S-D66/Wmh
One difference: module efficiency
Same series, other bin
Suntech STP665S-D66/Wmh vs Suntech STP660S-D66/Pmh+
7 differences, the largest is performance warranty
06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP665S-D66/Wmh or Suntech STP670S-D66/Wmh?
According to our database: Suntech STP670S-D66/Wmh has higher module efficiency (21.60% vs 21.40%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Suntech STP665S-D66/Wmh and Suntech STP670S-D66/Wmh?
Suntech STP665S-D66/Wmh has a module efficiency of 21.40%, while Suntech STP670S-D66/Wmh is 21.60%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Suntech STP665S-D66/Wmh use vs Suntech STP670S-D66/Wmh?
Suntech STP665S-D66/Wmh uses TOPCon cells; Suntech STP670S-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 STP665S-D66/Wmh and Suntech STP670S-D66/Wmh?
Suntech STP665S-D66/Wmh has a 25 years power warranty; Suntech STP670S-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 26 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.