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48QGSF-475 vs 66QGDF-660 7 of 19 identical Swap Change panels

Suntech STP-NT11/48QGSF-475 vs Suntech STP-NT11/66QGDF-660

Suntech STP-NT11/48QGSF-475
STP-NT11/48QGSF-475
475 Wp 23.80 % TOPCon
Open panel page Datasheet PDF
VS
Suntech STP-NT11/66QGDF-660
STP-NT11/66QGDF-660
660 Wp 24.40 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

12 differences, and they point both ways

The largest is rated power: 185 W more power. 7 of 19 comparable parameters are identical.

See all 12 differences
How alike are they
7 of 19 comparable
parameters are identical
identical differs
01

What actually differs

12 of 19 parameters
Parameter 48QGSF-475 66QGDF-660 Difference
Rated power 475 Wp 660 Wp 185 W more power
Module efficiency 23.80 % 24.40 % 0.60 pp more efficient
Weight 21.5 kg 33.1 kg 11.6 kg lighter
Product warranty 25 yrs 15 yrs 10 yrs longer
Power density 237.7 Wp/m² 244.3 Wp/m² 6.6 Wp/m² higher
Open-circuit voltage 36.53 V 50.30 V 13.77 V apart
Module area 1.998 m² 2.701 m² 0.703 m² apart
Weight per kWp 45.3 kg/kWp 50.2 kg/kWp 4.9 kg/kWp lighter
Voltage at max power 30.43 V 42.08 V 11.65 V apart
Cell count 192 264 72 cells apart
Bifacial No Yes No vs Yes
Dimensions 1762x1134x30 mm 2382x1134x30 mm 1762x1134x30 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 (-0.260 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
48QGSF-475
16,061 kWh
66QGDF-660
22,317 kWh
Lifetime gap
6,256 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 48QGSF-475 66QGDF-660
Standard test conditions 25 °C 100.0% of rated power 475 W 660 W
Cool, bright day 40 °C 96.1% of rated power 456 W 634 W
Typical summer roof 55 °C 92.2% of rated power 438 W 609 W
Hot roof 70 °C 88.3% of rated power 419 W 583 W
03

Full specification

Parameter 48QGSF-475 66QGDF-660 Difference
Power and efficiency
Rated power 475 Wp 660 Wp +185 W for 66QGDF-660
Module efficiency 23.80 % 24.40 % +0.60 pp for 66QGDF-660
Power density 237.7 Wp/m² 244.3 Wp/m² +6.6 Wp/m² for 66QGDF-660
Open-circuit voltage 36.53 V 50.30 V 13.77 V apart
Voltage at max power 30.43 V 42.08 V 11.65 V apart
Short-circuit current 16.43 A 16.50 A Effectively the same
Current at max power 15.62 A 15.69 A Effectively the same
Temperature
Temperature coefficient -0.260 %/°C -0.260 %/°C Same
Mechanical
Dimensions 1762x1134x30 mm 2382x1134x30 mm 1762x1134x30 mm vs 2382x1134x30 mm
Module area 1.998 m² 2.701 m² 0.703 m² apart
Weight 21.5 kg 33.1 kg -11.6 kg for 48QGSF-475
Weight per kWp 45.3 kg/kWp 50.2 kg/kWp -4.9 kg/kWp for 48QGSF-475
Warranty and degradation
Product warranty 25 yrs 15 yrs +10 yrs for 48QGSF-475
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.35 %/yr 0.35 %/yr Same
Technology
Cell technology TOPCon TOPCon Same
Cell type Monocrystalline Monocrystalline Same
Cell count 192 264 72 cells apart
Bifacial No Yes No vs Yes
04

Against the whole database

14,129 panels
Efficiency
#462 vs #113
66QGDF-660 leads by 349 places
Power density
#497 vs #100
66QGDF-660 leads by 397 places
Heat behaviour
#515 vs #515
Tied - the same position in the database
Weight
#669 vs #3,668
48QGSF-475 leads by 2,999 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#3,803 vs #586
66QGDF-660 leads by 3,217 places
05

More useful comparisons

Open the full database
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Suntech STP-NT11/48QGSF-475 vs Suntech STP730S-D66-Nsh+
15 differences, the largest is rated power
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Suntech STP-NT11/48QGSF-475 vs Suntech STP-NT11/66QGDF-670
12 differences, the largest is module efficiency
Same series, other bin
Suntech STP-NT11/48QGSF-475 vs Suntech STP-NT11/66QGDF-665
12 differences, the largest is module efficiency
Same series, other bin
Suntech STP-NT11/48QGSF-475 vs Suntech STP-NT11/66QGDF-655
12 differences, the largest is rated power
Same series, other bin
Suntech STP-NT11/48QGSF-475 vs Suntech STP-NT11/66QGDF-650
11 differences, the largest is rated power
Same series, other bin
Suntech STP-NT11/48QGSF-475 vs Suntech STP-NT11/66QGDF-645
10 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP-NT11/48QGSF-475 or Suntech STP-NT11/66QGDF-660?
According to our database: Suntech STP-NT11/66QGDF-660 has higher module efficiency (24.40% vs 23.80%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Suntech STP-NT11/48QGSF-475 and Suntech STP-NT11/66QGDF-660?
Suntech STP-NT11/48QGSF-475 has a module efficiency of 23.80%, while Suntech STP-NT11/66QGDF-660 is 24.40%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Suntech STP-NT11/48QGSF-475 use vs Suntech STP-NT11/66QGDF-660?
Suntech STP-NT11/48QGSF-475 uses TOPCon cells; Suntech STP-NT11/66QGDF-660 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 STP-NT11/48QGSF-475 and Suntech STP-NT11/66QGDF-660?
Suntech STP-NT11/48QGSF-475 has a 30 years power warranty; Suntech STP-NT11/66QGDF-660 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 STP-NT11/48QGSF-475 and Suntech STP-NT11/66QGDF-660 bifacial panels?
Suntech STP-NT11/66QGDF-660 is bifacial (captures light from both faces); Suntech STP-NT11/48QGSF-475 is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

Shop prices: See 14 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.