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2.1 635W vs 1.2 FullBlack 280W 7 of 19 identical Swap Change panels

Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 1.2 FullBlack 280W

Heckert Solar
ZEUS 2.1 635W
635 Wp 23.50 % TOPCon Bifacial
Open panel page Datasheet PDF
VS
Heckert Solar
ZEUS 1.2 FullBlack 280W
280 Wp 23.31 % Back Contact Bifacial
Open panel page Datasheet PDF
The verdict

1.2 FullBlack 280W leads on the differences that matter

The largest is rated power: 355 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 2.1 635W 1.2 FullBlack 280W Difference
Rated power 635 Wp 280 Wp 355 W more power
Weight 32.5 kg 14.3 kg 18.2 kg lighter
Product warranty 12 yrs 30 yrs 18 yrs longer
Temperature coefficient -0.280 %/°C -0.260 %/°C 0.020 %/°C better in heat
Open-circuit voltage 49.60 V 24.11 V 25.49 V apart
Module area 2.701 m² 1.201 m² 1.500 m² apart
Short-circuit current 16.26 A 14.72 A 1.54 A apart
Cell technology TOPCon Back Contact TOPCon vs Back Contact
Voltage at max power 41.24 V 20.49 V 20.75 V apart
Cell count 132 64 68 cells apart
Current at max power 15.40 A 13.67 A 1.73 A apart
Dimensions 2382x1134x30 mm 1560x770x35 mm 2382x1134x30 mm vs 1560x770x35 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
2.1 635W
20,911 kWh
1.2 FullBlack 280W
9,221 kWh
Lifetime gap
11,690 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 2.1 635W 1.2 FullBlack 280W
Standard test conditions 25 °C 100.0% of rated power 635 W 280 W
Cool, bright day 40 °C 95.8% of rated power 608 W 269 W
Typical summer roof 55 °C 91.6% of rated power 582 W 258 W
Hot roof 70 °C 87.4% of rated power 555 W 247 W
03

Full specification

Parameter 2.1 635W 1.2 FullBlack 280W Difference
Power and efficiency
Rated power 635 Wp 280 Wp +355 W for 2.1 635W
Module efficiency 23.50 % 23.31 % Effectively the same
Power density 235.1 Wp/m² 233.1 Wp/m² Effectively the same
Open-circuit voltage 49.60 V 24.11 V 25.49 V apart
Voltage at max power 41.24 V 20.49 V 20.75 V apart
Short-circuit current 16.26 A 14.72 A 1.54 A apart
Current at max power 15.40 A 13.67 A 1.73 A apart
Temperature
Temperature coefficient -0.280 %/°C -0.260 %/°C +0.020 %/°C for 1.2 FullBlack 280W
Mechanical
Dimensions 2382x1134x30 mm 1560x770x35 mm 2382x1134x30 mm vs 1560x770x35 mm
Module area 2.701 m² 1.201 m² 1.500 m² apart
Weight 32.5 kg 14.3 kg -18.2 kg for 1.2 FullBlack 280W
Weight per kWp 51.2 kg/kWp 51.1 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 30 yrs +18 yrs for 1.2 FullBlack 280W
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.45 %/yr 0.45 %/yr Same
Technology
Cell technology TOPCon Back Contact TOPCon vs Back Contact
Cell type Monocrystalline Monocrystalline Same
Cell count 132 64 68 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,129 panels
Efficiency
#749 vs #1,055
2.1 635W leads by 306 places
Power density
#777 vs #1,136
2.1 635W leads by 359 places
Heat behaviour
#1,347 vs #515
1.2 FullBlack 280W leads by 832 places
Weight
#4,581 vs #4,429
1.2 FullBlack 280W leads by 152 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#1,760 vs #9,828
2.1 635W leads by 8,068 places
05

More useful comparisons

Open the full database
Same series, other bin
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Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 2.1-640
2 differences, the largest is cell technology
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Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 2.1 640W
One difference: module efficiency
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Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 2.1-635
One difference: cell technology
Same series, other bin
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Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 1.2-280
12 differences, the largest is rated power
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Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 1.2 FullBlack 275W
14 differences, the largest is rated power
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Heckert Solar ZEUS 2.1 635W vs Heckert Solar ZEUS 1.2-275
14 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: Heckert Solar ZEUS 2.1 635W or Heckert Solar ZEUS 1.2 FullBlack 280W?
According to our database: Heckert Solar ZEUS 2.1 635 W has higher module efficiency (23.50% vs 23.31%); Heckert Solar ZEUS 1.2 FullBlack 280 W tolerates heat better (temp coeff -0.260%/°C vs -0.280%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Heckert Solar ZEUS 2.1 635W and Heckert Solar ZEUS 1.2 FullBlack 280W?
Heckert Solar ZEUS 2.1 635 W has a module efficiency of 23.50%, while Heckert Solar ZEUS 1.2 FullBlack 280 W is 23.31%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Heckert Solar ZEUS 2.1 635W use vs Heckert Solar ZEUS 1.2 FullBlack 280W?
Heckert Solar ZEUS 2.1 635 W uses TOPCon cells; Heckert Solar ZEUS 1.2 FullBlack 280 W uses Back Contact. 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 Heckert Solar ZEUS 2.1 635W and Heckert Solar ZEUS 1.2 FullBlack 280W?
Heckert Solar ZEUS 2.1 635 W has a 30 years power warranty; Heckert Solar ZEUS 1.2 FullBlack 280 W 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 Heckert Solar ZEUS 2.1 635W and Heckert Solar ZEUS 1.2 FullBlack 280W bifacial panels?
Both Heckert Solar ZEUS 2.1 635 W and Heckert Solar ZEUS 1.2 FullBlack 280 W 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.