Heckert Solar ZEUS 1.2-280 vs Heckert Solar ZEUS 2.1 640W
VS
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 differencesHow alike are they
5
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
14 of 19 parameters
What actually differs
Parameter
1.2-280
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
1.2-280
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
1.2-280
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
1.2-280
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 1.2-280
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 1.2-280
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 1.2-280
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
14,129 panels
Against the whole database
Efficiency
#1,055
vs
#549
2.1 640W leads by 506 places
Power density
#1,136
vs
#553
2.1 640W leads by 583 places
Heat behaviour
#515
vs
#1,347
1.2-280 leads by 832 places
Weight
#4,429
vs
#4,218
2.1 640W leads by 211 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#9,828
vs
#1,545
2.1 640W leads by 8,283 places
05
Open the full database
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06
Written summary
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07
Questions about this pairing
Which panel is better: Heckert Solar ZEUS 1.2-280 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 1.2-280 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 1.2-280 and Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 1.2-280 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 1.2-280 use vs Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 1.2-280 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 1.2-280 and Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 1.2-280 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 1.2-280 and Heckert Solar ZEUS 2.1 640W bifacial panels?
Both Heckert Solar ZEUS 1.2-280 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.