Heckert Solar ZEUS 2.1-640 vs Heckert Solar ZEUS 1.2-280
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
2.1-640
1.2-280
Difference
Rated power
640 Wp
280 Wp
360 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
Module efficiency
23.70 %
23.31 %
0.39 pp more efficient
Open-circuit voltage
49.75 V
24.11 V
25.64 V apart
Module area
2.701 m²
1.201 m²
1.500 m² apart
Short-circuit current
16.33 A
14.72 A
1.61 A apart
Power density
236.9 Wp/m²
233.1 Wp/m²
3.8 Wp/m² higher
Cell technology
N-type
Back Contact
N-type vs Back Contact
Voltage at max power
41.38 V
20.49 V
20.89 V apart
Cell count
132
64
68 cells apart
Current at max power
15.47 A
13.67 A
1.80 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
2.1-640
21,076 kWh
1.2-280
9,221 kWh
Lifetime gap
11,855 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
2.1-640
1.2-280
Standard test conditions
25 °C
100.0% of rated power
640 W
280 W
Cool, bright day
40 °C
95.8% of rated power
613 W
269 W
Typical summer roof
55 °C
91.6% of rated power
586 W
258 W
Hot roof
70 °C
87.4% of rated power
559 W
247 W
03
Full specification
Parameter
2.1-640
1.2-280
Difference
Power and efficiency
Rated power
640 Wp
280 Wp
+360 W for 2.1-640
Module efficiency
23.70 %
23.31 %
+0.39 pp for 2.1-640
Power density
236.9 Wp/m²
233.1 Wp/m²
+3.8 Wp/m² for 2.1-640
Open-circuit voltage
49.75 V
24.11 V
25.64 V apart
Voltage at max power
41.38 V
20.49 V
20.89 V apart
Short-circuit current
16.33 A
14.72 A
1.61 A apart
Current at max power
15.47 A
13.67 A
1.80 A apart
Temperature
Temperature coefficient
-0.280 %/°C
-0.260 %/°C
+0.020 %/°C for 1.2-280
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 1.2-280
Weight per kWp
50.8 kg/kWp
51.1 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
30 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
N-type
Back Contact
N-type vs Back Contact
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
132
64
68 cells apart
Bifacial
Yes
Yes
Same
04
14,129 panels
Against the whole database
Efficiency
#549
vs
#1,055
2.1-640 leads by 506 places
Power density
#553
vs
#1,136
2.1-640 leads by 583 places
Heat behaviour
#1,347
vs
#515
1.2-280 leads by 832 places
Weight
#4,218
vs
#4,429
2.1-640 leads by 211 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#1,545
vs
#9,828
2.1-640 leads by 8,283 places
05
Open the full database
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06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: Heckert Solar ZEUS 2.1-640 or Heckert Solar ZEUS 1.2-280?
According to our database: Heckert Solar ZEUS 2.1-640 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 2.1-640 and Heckert Solar ZEUS 1.2-280?
Heckert Solar ZEUS 2.1-640 has a module efficiency of 23.70%, while Heckert Solar ZEUS 1.2-280 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 2.1-640 use vs Heckert Solar ZEUS 1.2-280?
Heckert Solar ZEUS 2.1-640 uses N-type cells; Heckert Solar ZEUS 1.2-280 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 2.1-640 and Heckert Solar ZEUS 1.2-280?
Heckert Solar ZEUS 2.1-640 has a 30 years power warranty; Heckert Solar ZEUS 1.2-280 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 2.1-640 and Heckert Solar ZEUS 1.2-280 bifacial panels?
Both Heckert Solar ZEUS 2.1-640 and Heckert Solar ZEUS 1.2-280 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.