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66QGDF-645 vs 48QGSF-475 9 of 19 identical Swap Change panels

Suntech STP-NT11/66QGDF-645 vs Suntech STP-NT11/48QGSF-475

Suntech STP-NT11/66QGDF-645
STP-NT11/66QGDF-645
645 Wp 23.90 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Suntech STP-NT11/48QGSF-475
STP-NT11/48QGSF-475
475 Wp 23.80 % TOPCon
Open panel page Datasheet PDF
The verdict

48QGSF-475 leads on the differences that matter

The largest is rated power: 170 W more power. 9 of 19 comparable parameters are identical.

See all 10 differences
How alike are they
9 of 19 comparable
parameters are identical
identical differs
01

What actually differs

10 of 19 parameters
Parameter 66QGDF-645 48QGSF-475 Difference
Rated power 645 Wp 475 Wp 170 W more power
Weight 33.1 kg 21.5 kg 11.6 kg lighter
Product warranty 15 yrs 25 yrs 10 yrs longer
Weight per kWp 51.3 kg/kWp 45.3 kg/kWp 6.1 kg/kWp lighter
Open-circuit voltage 49.85 V 36.53 V 13.32 V apart
Module area 2.701 m² 1.998 m² 0.703 m² apart
Voltage at max power 41.62 V 30.43 V 11.19 V apart
Cell count 264 192 72 cells apart
Bifacial Yes No Yes vs No
Dimensions 2382x1134x30 mm 1762x1134x30 mm 2382x1134x30 mm vs 1762x1134x30 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.
66QGDF-645
21,809 kWh
48QGSF-475
16,061 kWh
Lifetime gap
5,748 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 66QGDF-645 48QGSF-475
Standard test conditions 25 °C 100.0% of rated power 645 W 475 W
Cool, bright day 40 °C 96.1% of rated power 620 W 456 W
Typical summer roof 55 °C 92.2% of rated power 595 W 438 W
Hot roof 70 °C 88.3% of rated power 570 W 419 W
03

Full specification

Parameter 66QGDF-645 48QGSF-475 Difference
Power and efficiency
Rated power 645 Wp 475 Wp +170 W for 66QGDF-645
Module efficiency 23.90 % 23.80 % Effectively the same
Power density 238.8 Wp/m² 237.7 Wp/m² Effectively the same
Open-circuit voltage 49.85 V 36.53 V 13.32 V apart
Voltage at max power 41.62 V 30.43 V 11.19 V apart
Short-circuit current 16.29 A 16.43 A Effectively the same
Current at max power 15.50 A 15.62 A Effectively the same
Temperature
Temperature coefficient -0.260 %/°C -0.260 %/°C Same
Mechanical
Dimensions 2382x1134x30 mm 1762x1134x30 mm 2382x1134x30 mm vs 1762x1134x30 mm
Module area 2.701 m² 1.998 m² 0.703 m² apart
Weight 33.1 kg 21.5 kg -11.6 kg for 48QGSF-475
Weight per kWp 51.3 kg/kWp 45.3 kg/kWp -6.1 kg/kWp for 48QGSF-475
Warranty and degradation
Product warranty 15 yrs 25 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 264 192 72 cells apart
Bifacial Yes No Yes vs No
04

Against the whole database

14,129 panels
Efficiency
#378 vs #462
66QGDF-645 leads by 84 places
Power density
#383 vs #497
66QGDF-645 leads by 114 places
Heat behaviour
#515 vs #515
Tied - the same position in the database
Weight
#4,717 vs #669
48QGSF-475 leads by 4,048 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#1,098 vs #3,803
66QGDF-645 leads by 2,705 places
05

More useful comparisons

Open the full database
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Suntech STP-NT11/66QGDF-645 vs Suntech STP-NT11/66QGDF-670
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Suntech STP-NT11/66QGDF-645 vs Suntech STP-NT11/66QGDF-665
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Suntech STP-NT11/66QGDF-645 vs Suntech STP-NT11/66QGDF-660
3 differences, the largest is module efficiency
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Suntech STP-NT11/66QGDF-645 vs Suntech STP-NT11/66QGDF-655
3 differences, the largest is module efficiency
Same series, other bin
Suntech STP-NT11/66QGDF-645 vs Suntech STP-NT11/66QGDF-650
One difference: module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP-NT11/66QGDF-645 or Suntech STP-NT11/48QGSF-475?
According to our database: Suntech STP-NT11/66QGDF-645 has higher module efficiency (23.90% 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-NT11/66QGDF-645 and Suntech STP-NT11/48QGSF-475?
Suntech STP-NT11/66QGDF-645 has a module efficiency of 23.90%, while Suntech STP-NT11/48QGSF-475 is 23.80%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Suntech STP-NT11/66QGDF-645 use vs Suntech STP-NT11/48QGSF-475?
Suntech STP-NT11/66QGDF-645 uses TOPCon cells; Suntech STP-NT11/48QGSF-475 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-NT11/66QGDF-645 and Suntech STP-NT11/48QGSF-475?
Suntech STP-NT11/66QGDF-645 has a 30 years power warranty; Suntech STP-NT11/48QGSF-475 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-NT11/66QGDF-645 and Suntech STP-NT11/48QGSF-475 bifacial panels?
Suntech STP-NT11/66QGDF-645 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.