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NEG18RC.27-515 vs NEG21C.20Q-755 4 of 19 identical Swap Change panels

Trina Solar TSM-NEG18RC.27-515 vs Trina Solar TSM-NEG21C.20Q-755

Trina Solar TSM-NEG18RC.27-515
TSM-NEG18RC.27-515
515 Wp 23.20 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Trina Solar TSM-NEG21C.20Q-755
TSM-NEG21C.20Q-755
755 Wp 24.30 % TOPCon Bifacial
Open panel page Datasheet PDF
The verdict

NEG21C.20Q-755 leads on the differences that matter

The largest is module efficiency: 1.10 pp more efficient. 4 of 19 comparable parameters are identical.

See all 15 differences
How alike are they
4 of 19 comparable
parameters are identical
identical differs
01

What actually differs

15 of 19 parameters
Parameter NEG18RC.27-515 NEG21C.20Q-755 Difference
Module efficiency 23.20 % 24.30 % 1.10 pp more efficient
Rated power 515 Wp 755 Wp 240 W more power
Power density 231.6 Wp/m² 243.1 Wp/m² 11.5 Wp/m² higher
Temperature coefficient -0.290 %/°C -0.260 %/°C 0.030 %/°C better in heat
Weight 23.5 kg 38.3 kg 14.8 kg lighter
Product warranty 15 yrs 12 yrs 3 yrs longer
Open-circuit voltage 40.90 V 50.70 V 9.80 V apart
Short-circuit current 15.96 A 18.81 A 2.85 A apart
Module area 2.224 m² 3.106 m² 0.883 m² apart
Weight per kWp 45.6 kg/kWp 50.7 kg/kWp 5.1 kg/kWp lighter
Annual degradation 0.40 %/yr 0.35 %/yr 0.05 %/yr slower
Voltage at max power 33.90 V 42.70 V 8.80 V apart
Current at max power 15.20 A 17.69 A 2.49 A apart
Cell count 108 264 156 cells apart
Dimensions 1961x1134x30 mm 2384x1303x33 mm 1961x1134x30 mm vs 2384x1303x33 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
NEG18RC.27-515
17,279 kWh
NEG21C.20Q-755
25,529 kWh
Lifetime gap
8,250 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario NEG18RC.27-515 NEG21C.20Q-755
Standard test conditions 25 °C 100.0% of rated power 515 W 755 W
Cool, bright day 40 °C 95.7% of rated power 493 W 726 W
Typical summer roof 55 °C 91.3% of rated power 470 W 696 W
Hot roof 70 °C 87.0% of rated power 448 W 667 W
03

Full specification

Parameter NEG18RC.27-515 NEG21C.20Q-755 Difference
Power and efficiency
Rated power 515 Wp 755 Wp +240 W for NEG21C.20Q-755
Module efficiency 23.20 % 24.30 % +1.10 pp for NEG21C.20Q-755
Power density 231.6 Wp/m² 243.1 Wp/m² +11.5 Wp/m² for NEG21C.20Q-755
Open-circuit voltage 40.90 V 50.70 V 9.80 V apart
Voltage at max power 33.90 V 42.70 V 8.80 V apart
Short-circuit current 15.96 A 18.81 A 2.85 A apart
Current at max power 15.20 A 17.69 A 2.49 A apart
Temperature
Temperature coefficient -0.290 %/°C -0.260 %/°C +0.030 %/°C for NEG21C.20Q-755
Mechanical
Dimensions 1961x1134x30 mm 2384x1303x33 mm 1961x1134x30 mm vs 2384x1303x33 mm
Module area 2.224 m² 3.106 m² 0.883 m² apart
Weight 23.5 kg 38.3 kg -14.8 kg for NEG18RC.27-515
Weight per kWp 45.6 kg/kWp 50.7 kg/kWp -5.1 kg/kWp for NEG18RC.27-515
Warranty and degradation
Product warranty 15 yrs 12 yrs +3 yrs for NEG18RC.27-515
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/yr 0.35 %/yr -0.05 %/yr for NEG21C.20Q-755
Technology
Cell technology TOPCon TOPCon Same
Cell type Monocrystalline Monocrystalline Same
Cell count 108 264 156 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#1,306 vs #131
NEG21C.20Q-755 leads by 1,175 places
Power density
#1,473 vs #136
NEG21C.20Q-755 leads by 1,337 places
Heat behaviour
#2,165 vs #511
NEG21C.20Q-755 leads by 1,654 places
Weight
#789 vs #4,131
NEG18RC.27-515 leads by 3,342 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#5,086 vs #91
NEG21C.20Q-755 leads by 4,995 places
05

More useful comparisons

Open the full database
Same series, other bin
Trina Solar TSM-NEG18RC.27-515 vs Trina Solar TSM-NEG18RC.27-510
One difference: module efficiency
Same series, other bin
Trina Solar TSM-NEG18RC.27-515 vs Trina Solar TSM-NEG18RC.27-505
3 differences, the largest is module efficiency
Same series, other bin
Trina Solar TSM-NEG18RC.27-515 vs Trina Solar TSM-NEG18RC.27-500
3 differences, the largest is module efficiency
Same series, other bin
Trina Solar TSM-NEG18RC.27-515 vs Trina Solar TSM-NEG18RC.27-495
4 differences, the largest is module efficiency
Same series, other bin
Trina Solar TSM-NEG18RC.27-515 vs Trina Solar TSM-NEG18RC.27-490
6 differences, the largest is module efficiency
Same series, other bin
Trina Solar TSM-NEG21C.20Q-755 vs Trina Solar TSM-NEG21C.20Q-760
One difference: module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Trina Solar TSM-NEG18RC.27-515 or Trina Solar TSM-NEG21C.20Q-755?
According to our database: Trina Solar TSM-NEG21C.20Q-755 has higher module efficiency (24.30% vs 23.20%); Trina Solar TSM-NEG21C.20Q-755 tolerates heat better (temp coeff -0.260%/°C vs -0.290%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Trina Solar TSM-NEG18RC.27-515 and Trina Solar TSM-NEG21C.20Q-755?
Trina Solar TSM-NEG18RC.27-515 has a module efficiency of 23.20%, while Trina Solar TSM-NEG21C.20Q-755 is 24.30%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Trina Solar TSM-NEG18RC.27-515 use vs Trina Solar TSM-NEG21C.20Q-755?
Trina Solar TSM-NEG18RC.27-515 uses TOPCon cells; Trina Solar TSM-NEG21C.20Q-755 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 Trina Solar TSM-NEG18RC.27-515 and Trina Solar TSM-NEG21C.20Q-755?
Trina Solar TSM-NEG18RC.27-515 has a 30 years power warranty; Trina Solar TSM-NEG21C.20Q-755 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-NEG18RC.27-515 and Trina Solar TSM-NEG21C.20Q-755 bifacial panels?
Both Trina Solar TSM-NEG18RC.27-515 and Trina Solar TSM-NEG21C.20Q-755 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 213 Trina Solar 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.