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1.2 FullBlack 280W vs 2.1 640W 5 of 19 identical Swap Change panels

Heckert Solar ZEUS 1.2 FullBlack 280W vs Heckert Solar ZEUS 2.1 640W

Heckert Solar
ZEUS 1.2 FullBlack 280W
280 Wp 23.31 % Back Contact Bifacial
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VS
Heckert Solar
ZEUS 2.1 640W
640 Wp 23.70 % TOPCon Bifacial
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The verdict

14 differences, and they point both ways

The largest is rated power: 360 W more power. 5 of 19 comparable parameters are identical.

See all 14 differences
How alike are they
5 of 19 comparable
parameters are identical
identical differs
01

What actually differs

14 of 19 parameters
Parameter 1.2 FullBlack 280W 2.1 640W Difference
Rated power 280 Wp 640 Wp 360 W more power
Weight 14.3 kg 32.5 kg 18.2 kg lighter
Product warranty 30 yrs 12 yrs 18 yrs longer
Temperature coefficient -0.260 %/°C -0.280 %/°C 0.020 %/°C better in heat
Module efficiency 23.31 % 23.70 % 0.39 pp more efficient
Open-circuit voltage 24.11 V 49.75 V 25.64 V apart
Module area 1.201 m² 2.701 m² 1.500 m² apart
Short-circuit current 14.72 A 16.33 A 1.61 A apart
Power density 233.1 Wp/m² 236.9 Wp/m² 3.8 Wp/m² higher
Cell technology Back Contact TOPCon Back Contact vs TOPCon
Voltage at max power 20.49 V 41.38 V 20.89 V apart
Cell count 64 132 68 cells apart
Current at max power 13.67 A 15.47 A 1.80 A apart
Dimensions 1560x770x35 mm 2382x1134x30 mm 1560x770x35 mm vs 2382x1134x30 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
1.2 FullBlack 280W
9,221 kWh
2.1 640W
21,076 kWh
Lifetime gap
11,855 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 1.2 FullBlack 280W 2.1 640W
Standard test conditions 25 °C 100.0% of rated power 280 W 640 W
Cool, bright day 40 °C 95.8% of rated power 269 W 613 W
Typical summer roof 55 °C 91.6% of rated power 258 W 586 W
Hot roof 70 °C 87.4% of rated power 247 W 559 W
03

Full specification

Parameter 1.2 FullBlack 280W 2.1 640W Difference
Power and efficiency
Rated power 280 Wp 640 Wp +360 W for 2.1 640W
Module efficiency 23.31 % 23.70 % +0.39 pp for 2.1 640W
Power density 233.1 Wp/m² 236.9 Wp/m² +3.8 Wp/m² for 2.1 640W
Open-circuit voltage 24.11 V 49.75 V 25.64 V apart
Voltage at max power 20.49 V 41.38 V 20.89 V apart
Short-circuit current 14.72 A 16.33 A 1.61 A apart
Current at max power 13.67 A 15.47 A 1.80 A apart
Temperature
Temperature coefficient -0.260 %/°C -0.280 %/°C +0.020 %/°C for 1.2 FullBlack 280W
Mechanical
Dimensions 1560x770x35 mm 2382x1134x30 mm 1560x770x35 mm vs 2382x1134x30 mm
Module area 1.201 m² 2.701 m² 1.500 m² apart
Weight 14.3 kg 32.5 kg -18.2 kg for 1.2 FullBlack 280W
Weight per kWp 51.1 kg/kWp 50.8 kg/kWp Effectively the same
Warranty and degradation
Product warranty 30 yrs 12 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 Back Contact TOPCon Back Contact vs TOPCon
Cell type Monocrystalline Monocrystalline Same
Cell count 64 132 68 cells apart
Bifacial Yes Yes Same
04

Against the whole database

13,953 panels
Efficiency
#1,004 vs #511
2.1 640W leads by 493 places
Power density
#1,084 vs #515
2.1 640W leads by 569 places
Heat behaviour
#511 vs #1,290
1.2 FullBlack 280W leads by 779 places
Weight
#4,382 vs #4,174
2.1 640W leads by 208 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#9,692 vs #1,515
2.1 640W leads by 8,177 places
05

More useful comparisons

Open the full database
Same series, other bin
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Heckert Solar ZEUS 1.2 FullBlack 280W vs Heckert Solar ZEUS 1.2 FullBlack 275W
2 differences, the largest is module efficiency
Same series, other bin
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Heckert Solar ZEUS 1.2 FullBlack 280W vs Heckert Solar ZEUS 1.2 FullBlack 270W
3 differences, the largest is module efficiency
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Heckert Solar ZEUS 2.1 640W vs Heckert Solar ZEUS 2.1-640
One difference: cell technology
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Heckert Solar ZEUS 2.1 640W vs Heckert Solar ZEUS 2.1-635
2 differences, the largest is cell technology
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Heckert Solar ZEUS 2.1 640W vs Heckert Solar ZEUS 2.1 635W
One difference: module efficiency
Same series, other bin
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Heckert Solar ZEUS 2.1 640W vs Heckert Solar ZEUS 1.2-280
14 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: Heckert Solar ZEUS 1.2 FullBlack 280W or Heckert Solar ZEUS 2.1 640W?
According to our database: Heckert Solar ZEUS 2.1 640 W has higher module efficiency (23.70% 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 1.2 FullBlack 280W and Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 1.2 FullBlack 280 W has a module efficiency of 23.31%, while Heckert Solar ZEUS 2.1 640 W is 23.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Heckert Solar ZEUS 1.2 FullBlack 280W use vs Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 1.2 FullBlack 280 W uses Back Contact cells; Heckert Solar ZEUS 2.1 640 W 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 Heckert Solar ZEUS 1.2 FullBlack 280W and Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 1.2 FullBlack 280 W has a 30 years power warranty; Heckert Solar ZEUS 2.1 640 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 1.2 FullBlack 280W and Heckert Solar ZEUS 2.1 640W bifacial panels?
Both Heckert Solar ZEUS 1.2 FullBlack 280 W and Heckert Solar ZEUS 2.1 640 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.

Shop prices: See 16 Heckert 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.