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NEG21C.20 740 vs DEG21C.20-660 10 of 19 identical Swap Change panels

Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-DEG21C.20-660

Trina Solar TSM-NEG21C.20 740
TSM-NEG21C.20 740
740 Wp 23.80 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Trina Solar TSM-DEG21C.20-660
TSM-DEG21C.20-660
660 Wp 21.20 % PERC Bifacial
Open panel page Datasheet PDF
The verdict

NEG21C.20 740 leads on the differences that matter

The largest is module efficiency: 2.60 pp more efficient. 10 of 19 comparable parameters are identical.

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

What actually differs

9 of 19 parameters
Parameter NEG21C.20 740 DEG21C.20-660 Difference
Module efficiency 23.80 % 21.20 % 2.60 pp more efficient
Temperature coefficient -0.290 %/°C -0.340 %/°C 0.050 %/°C better in heat
Rated power 740 Wp 660 Wp 80 W more power
Power density 238.2 Wp/m² 212.5 Wp/m² 25.8 Wp/m² higher
Weight per kWp 51.8 kg/kWp 58.0 kg/kWp 6.3 kg/kWp lighter
Open-circuit voltage 50.30 V 45.90 V 4.40 V apart
Cell technology TOPCon PERC TOPCon vs PERC
Voltage at max power 42.10 V 38.10 V 4.00 V apart
Annual degradation 0.40 %/yr 0.45 %/yr 0.05 %/yr slower
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
NEG21C.20 740
24,828 kWh
DEG21C.20-660
21,734 kWh
Lifetime gap
3,094 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario NEG21C.20 740 DEG21C.20-660
Standard test conditions 25 °C 100.0% of rated power 740 W 660 W
Cool, bright day 40 °C 94.9% of rated power 708 W 626 W
Typical summer roof 55 °C 89.8% of rated power 676 W 593 W
Hot roof 70 °C 84.7% of rated power 643 W 559 W
03

Full specification

Parameter NEG21C.20 740 DEG21C.20-660 Difference
Power and efficiency
Rated power 740 Wp 660 Wp +80 W for NEG21C.20 740
Module efficiency 23.80 % 21.20 % +2.60 pp for NEG21C.20 740
Power density 238.2 Wp/m² 212.5 Wp/m² +25.8 Wp/m² for NEG21C.20 740
Open-circuit voltage 50.30 V 45.90 V 4.40 V apart
Voltage at max power 42.10 V 38.10 V 4.00 V apart
Short-circuit current 18.66 A 18.45 A Effectively the same
Current at max power 17.58 A 17.35 A Effectively the same
Temperature
Temperature coefficient -0.290 %/°C -0.340 %/°C +0.050 %/°C for NEG21C.20 740
Mechanical
Dimensions 2384x1303x33 mm 2384x1303x33 mm Same
Module area 3.106 m² 3.106 m² Same
Weight 38.3 kg 38.3 kg Same
Weight per kWp 51.8 kg/kWp 58.0 kg/kWp -6.3 kg/kWp for NEG21C.20 740
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/yr 0.45 %/yr -0.05 %/yr for NEG21C.20 740
Technology
Cell technology TOPCon PERC TOPCon vs PERC
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,129 panels
Efficiency
#462 vs #9,145
NEG21C.20 740 leads by 8,683 places
Power density
#460 vs #9,028
NEG21C.20 740 leads by 8,568 places
Heat behaviour
#2,220 vs #8,846
NEG21C.20 740 leads by 6,626 places
Weight
#5,156 vs #11,616
NEG21C.20 740 leads by 6,460 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#185 vs #3,269
NEG21C.20 740 leads by 3,084 places
05

More useful comparisons

Open the full database
Same series, other bin
Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-NEG21C.20Q-760
6 differences, the largest is module efficiency
Same series, other bin
Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-NEG21C.20Q-755
6 differences, the largest is temperature coefficient
Same series, other bin
Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-NEG21C.20Q-750
6 differences, the largest is temperature coefficient
Same series, other bin
Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-NEG21C.20Q-745
4 differences, the largest is temperature coefficient
Same series, other bin
Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-NEG21C.20-740
The same specification on paper
Same series, other bin
Trina Solar TSM-NEG21C.20 740 vs Trina Solar TSM-NEG21C.20Q-740
3 differences, the largest is temperature coefficient
06

Written summary

07

Questions about this pairing

Which panel is better: Trina Solar TSM-NEG21C.20 740 or Trina Solar TSM-DEG21C.20-660?
According to our database: Trina Solar TSM-NEG21C.20 740 has higher module efficiency (23.80% vs 21.20%); Trina Solar TSM-NEG21C.20 740 tolerates heat better (temp coeff -0.290%/°C vs -0.340%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Trina Solar TSM-NEG21C.20 740 and Trina Solar TSM-DEG21C.20-660?
Trina Solar TSM-NEG21C.20 740 has a module efficiency of 23.80%, while Trina Solar TSM-DEG21C.20-660 is 21.20%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Trina Solar TSM-NEG21C.20 740 use vs Trina Solar TSM-DEG21C.20-660?
Trina Solar TSM-NEG21C.20 740 uses TOPCon cells; Trina Solar TSM-DEG21C.20-660 uses PERC. 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 Trina Solar TSM-NEG21C.20 740 and Trina Solar TSM-DEG21C.20-660?
Trina Solar TSM-NEG21C.20 740 has a 30 years power warranty; Trina Solar TSM-DEG21C.20-660 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 Trina Solar TSM-NEG21C.20 740 and Trina Solar TSM-DEG21C.20-660 bifacial panels?
Both Trina Solar TSM-NEG21C.20 740 and Trina Solar TSM-DEG21C.20-660 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.

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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.