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Pmh+ vs Wmh 13 of 19 identical Swap Change panels

Suntech STP665S-D66/Pmh+ vs Suntech STP665S-D66/Wmh

Suntech STP665S-D66/Pmh+
STP665S-D66/Pmh+
665 Wp 21.40 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Suntech STP665S-D66/Wmh
STP665S-D66/Wmh
665 Wp 21.40 % TOPCon
Open panel page Datasheet PDF
The verdict

Pmh+ leads on the differences that matter

The largest is performance warranty: 5 yrs longer. 13 of 19 comparable parameters are identical.

See all 6 differences
How alike are they
13 of 19 comparable
parameters are identical
identical differs
01

What actually differs

6 of 19 parameters
Parameter Pmh+ Wmh Difference
Performance warranty 30 yrs 25 yrs 5 yrs longer
Weight 37.5 kg 33.5 kg 4.0 kg lighter
Weight per kWp 56.4 kg/kWp 50.4 kg/kWp 6.0 kg/kWp lighter
Product warranty 15 yrs 12 yrs 3 yrs longer
Annual degradation 0.45 %/yr 0.55 %/yr 0.10 %/yr slower
Bifacial Yes No Yes vs No
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.
Pmh+
21,899 kWh
Wmh
21,552 kWh
Lifetime gap
347 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario Pmh+ Wmh
Standard test conditions 25 °C 100.0% of rated power 665 W 665 W
Cool, bright day 40 °C 94.9% of rated power 631 W 631 W
Typical summer roof 55 °C 89.8% of rated power 597 W 597 W
Hot roof 70 °C 84.7% of rated power 563 W 563 W
03

Full specification

Parameter Pmh+ Wmh Difference
Power and efficiency
Rated power 665 Wp 665 Wp Same
Module efficiency 21.40 % 21.40 % Same
Power density 214.1 Wp/m² 214.1 Wp/m² Same
Open-circuit voltage 46.25 V 46.25 V Same
Voltage at max power 38.25 V 38.25 V Same
Short-circuit current 18.39 A 18.39 A Same
Current at max power 17.39 A 17.39 A 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 37.5 kg 33.5 kg -4.0 kg for Wmh
Weight per kWp 56.4 kg/kWp 50.4 kg/kWp -6.0 kg/kWp for Wmh
Warranty and degradation
Product warranty 15 yrs 12 yrs +3 yrs for Pmh+
Performance warranty 30 yrs 25 yrs +5 yrs for Pmh+
Annual degradation 0.45 %/yr 0.55 %/yr -0.10 %/yr for Pmh+
Technology
Cell technology TOPCon TOPCon Same
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial Yes No Yes vs No
04

Against the whole database

14,005 panels
Efficiency
#8,323 vs #8,323
Tied - the same position in the database
Power density
#8,250 vs #8,250
Tied - the same position in the database
Heat behaviour
#8,778 vs #8,778
Tied - the same position in the database
Weight
#10,635 vs #3,742
Wmh leads by 6,893 places
Warranty
#21 vs #9,798
Pmh+ leads by 9,777 places
Overall
#2,253 vs #3,792
Pmh+ leads by 1,539 places
05

More useful comparisons

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06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP665S-D66/Pmh+ or Suntech STP665S-D66/Wmh?
According to our database: both panels are closely matched on key specs - the decision often comes down to price and local availability. See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Suntech STP665S-D66/Pmh+ and Suntech STP665S-D66/Wmh?
Suntech STP665S-D66/Pmh+ has a module efficiency of 21.40%, while Suntech STP665S-D66/Wmh is 21.40%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Suntech STP665S-D66/Pmh+ use vs Suntech STP665S-D66/Wmh?
Suntech STP665S-D66/Pmh+ uses TOPCon cells; Suntech STP665S-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/Pmh+ and Suntech STP665S-D66/Wmh?
Suntech STP665S-D66/Pmh+ has a 30 years power warranty; Suntech STP665S-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.
Are Suntech STP665S-D66/Pmh+ and Suntech STP665S-D66/Wmh bifacial panels?
Suntech STP665S-D66/Pmh+ is bifacial (captures light from both faces); Suntech STP665S-D66/Wmh is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

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.