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1-640 vs 1 640W 18 of 19 identical Swap Change panels

Heckert Solar ZEUS 2.1-640 vs Heckert Solar ZEUS 2.1 640W

Heckert Solar
ZEUS 2.1-640
640 Wp 23.70 % N-type Bifacial
VS
Heckert Solar
ZEUS 2.1 640W
640 Wp 23.70 % TOPCon Bifacial
The verdict

One difference, none of them an advantage

The largest is cell technology: N-type vs TOPCon. 18 of 19 comparable parameters are identical.

See the one difference
How alike are they
18 of 19 comparable
parameters are identical
identical differs
01

What actually differs

1 of 19 parameters
Parameter 1-640 1 640W Difference
Cell technology N-type TOPCon N-type vs TOPCon
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
Same temp coeff. for both panels (-0.280 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
1-640
21,076 kWh
1 640W
21,076 kWh
Lifetime gap
No difference
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 1-640 1 640W
Standard test conditions 25 °C 100.0% of rated power 640 W 640 W
Cool, bright day 40 °C 95.8% of rated power 613 W 613 W
Typical summer roof 55 °C 91.6% of rated power 586 W 586 W
Hot roof 70 °C 87.4% of rated power 559 W 559 W
03

Full specification

Parameter 1-640 1 640W Difference
Power and efficiency
Rated power 640 Wp 640 Wp Same
Module efficiency 23.70 % 23.70 % Same
Power density 236.9 Wp/m² 236.9 Wp/m² Same
Open-circuit voltage 49.75 V 49.75 V Same
Voltage at max power 41.38 V 41.38 V Same
Short-circuit current 16.33 A 16.33 A Same
Current at max power 15.47 A 15.47 A Same
Temperature
Temperature coefficient -0.280 %/°C -0.280 %/°C Same
Mechanical
Dimensions 2382x1134x30 mm 2382x1134x30 mm Same
Module area 2.701 m² 2.701 m² Same
Weight 32.5 kg 32.5 kg Same
Weight per kWp 50.8 kg/kWp 50.8 kg/kWp Same
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.45 %/yr 0.45 %/yr Same
Technology
Cell technology N-type TOPCon N-type vs TOPCon
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,129 panels
Efficiency
#549 vs #549
Tied - the same position in the database
Power density
#553 vs #553
Tied - the same position in the database
Heat behaviour
#1,347 vs #1,347
Tied - the same position in the database
Weight
#4,218 vs #4,218
Tied - the same position in the database
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#1,545 vs #1,545
Tied - the same position in the database
05

More useful comparisons

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06

Written summary

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07

Questions about this pairing

Which panel is better: Heckert Solar ZEUS 2.1-640 or Heckert Solar ZEUS 2.1 640W?
According to our database: both panels are closely matched on key specs - the decision often comes down to price and local availability. 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 2.1 640W?
Heckert Solar ZEUS 2.1-640 has a module efficiency of 23.70%, 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 2.1-640 use vs Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 2.1-640 uses N-type 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 2.1-640 and Heckert Solar ZEUS 2.1 640W?
Heckert Solar ZEUS 2.1-640 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 2.1-640 and Heckert Solar ZEUS 2.1 640W bifacial panels?
Both Heckert Solar ZEUS 2.1-640 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.