Skip to main content
66QGDF-665 vs 48QGDF-475 8 of 19 identical Swap Change panels

Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/48QGDF-475

Suntech STP-NT11/66QGDF-665
STP-NT11/66QGDF-665
665 Wp 24.60 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Suntech STP-NT11/48QGDF-475
STP-NT11/48QGDF-475
475 Wp 23.80 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

66QGDF-665 leads on the differences that matter

The largest is module efficiency: 0.80 pp more efficient. 8 of 19 comparable parameters are identical.

See all 11 differences
How alike are they
8 of 19 comparable
parameters are identical
identical differs
01

What actually differs

11 of 19 parameters
Parameter 66QGDF-665 48QGDF-475 Difference
Module efficiency 24.60 % 23.80 % 0.80 pp more efficient
Rated power 665 Wp 475 Wp 190 W more power
Weight 33.1 kg 21.5 kg 11.6 kg lighter
Product warranty 15 yrs 25 yrs 10 yrs longer
Power density 246.2 Wp/m² 237.7 Wp/m² 8.5 Wp/m² higher
Open-circuit voltage 50.45 V 36.53 V 13.92 V apart
Module area 2.701 m² 1.998 m² 0.703 m² apart
Weight per kWp 49.8 kg/kWp 45.3 kg/kWp 4.5 kg/kWp lighter
Voltage at max power 42.21 V 30.43 V 11.78 V apart
Cell count 264 192 72 cells apart
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-665
22,486 kWh
48QGDF-475
16,061 kWh
Lifetime gap
6,425 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 66QGDF-665 48QGDF-475
Standard test conditions 25 °C 100.0% of rated power 665 W 475 W
Cool, bright day 40 °C 96.1% of rated power 639 W 456 W
Typical summer roof 55 °C 92.2% of rated power 613 W 438 W
Hot roof 70 °C 88.3% of rated power 587 W 419 W
03

Full specification

Parameter 66QGDF-665 48QGDF-475 Difference
Power and efficiency
Rated power 665 Wp 475 Wp +190 W for 66QGDF-665
Module efficiency 24.60 % 23.80 % +0.80 pp for 66QGDF-665
Power density 246.2 Wp/m² 237.7 Wp/m² +8.5 Wp/m² for 66QGDF-665
Open-circuit voltage 50.45 V 36.53 V 13.92 V apart
Voltage at max power 42.21 V 30.43 V 11.78 V apart
Short-circuit current 16.57 A 16.43 A Effectively the same
Current at max power 15.76 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 48QGDF-475
Weight per kWp 49.8 kg/kWp 45.3 kg/kWp -4.5 kg/kWp for 48QGDF-475
Warranty and degradation
Product warranty 15 yrs 25 yrs +10 yrs for 48QGDF-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 Yes Same
04

Against the whole database

14,005 panels
Efficiency
#51 vs #433
66QGDF-665 leads by 382 places
Power density
#42 vs #467
66QGDF-665 leads by 425 places
Heat behaviour
#511 vs #511
Tied - the same position in the database
Weight
#3,223 vs #669
48QGDF-475 leads by 2,554 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#414 vs #3,753
66QGDF-665 leads by 3,339 places
05

More useful comparisons

Open the full database
Same series, other bin
Suntech STP-NT11/66QGDF-665 vs Suntech STP730S-D66-Nsh+
11 differences, the largest is module efficiency
Same series, other bin
Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-670
One difference: module efficiency
Same series, other bin
Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-660
One difference: module efficiency
Same series, other bin
Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-655
3 differences, the largest is module efficiency
Same series, other bin
Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-650
3 differences, the largest is module efficiency
Same series, other bin
Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-645
3 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Suntech STP-NT11/66QGDF-665 or Suntech STP-NT11/48QGDF-475?
According to our database: Suntech STP-NT11/66QGDF-665 has higher module efficiency (24.60% 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-665 and Suntech STP-NT11/48QGDF-475?
Suntech STP-NT11/66QGDF-665 has a module efficiency of 24.60%, while Suntech STP-NT11/48QGDF-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-665 use vs Suntech STP-NT11/48QGDF-475?
Suntech STP-NT11/66QGDF-665 uses TOPCon cells; Suntech STP-NT11/48QGDF-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-665 and Suntech STP-NT11/48QGDF-475?
Suntech STP-NT11/66QGDF-665 has a 30 years power warranty; Suntech STP-NT11/48QGDF-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-665 and Suntech STP-NT11/48QGDF-475 bifacial panels?
Both Suntech STP-NT11/66QGDF-665 and Suntech STP-NT11/48QGDF-475 are bifacial - they capture reflected light from the ground, which can add 5-15% more annual energy on ground-mount or elevated rooftop installations with a light surface beneath.

Shop prices: See 31 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.