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1.2-275 vs 2.1-635 5 of 19 identical Swap Change panels

Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 2.1-635

Heckert Solar ZEUS 1.2-275
Heckert Solar
ZEUS 1.2-275
275 Wp 22.89 % Back Contact Bifacial
VS
Heckert Solar
ZEUS 2.1-635
635 Wp 23.50 % N-type Bifacial
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 1.2-275 2.1-635 Difference
Rated power 275 Wp 635 Wp 360 W more power
Module efficiency 22.89 % 23.50 % 0.61 pp more efficient
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
Power density 228.9 Wp/m² 235.1 Wp/m² 6.1 Wp/m² higher
Open-circuit voltage 23.89 V 49.60 V 25.71 V apart
Module area 1.201 m² 2.701 m² 1.500 m² apart
Short-circuit current 14.65 A 16.26 A 1.61 A apart
Cell technology Back Contact N-type Back Contact vs N-type
Voltage at max power 20.36 V 41.24 V 20.88 V apart
Cell count 64 132 68 cells apart
Current at max power 13.51 A 15.40 A 1.89 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
1.2-275
9,056 kWh
2.1-635
20,911 kWh
Lifetime gap
11,855 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 1.2-275 2.1-635
Standard test conditions 25 °C 100.0% of rated power 275 W 635 W
Cool, bright day 40 °C 95.8% of rated power 264 W 608 W
Typical summer roof 55 °C 91.6% of rated power 254 W 582 W
Hot roof 70 °C 87.4% of rated power 243 W 555 W
03

Full specification

Parameter 1.2-275 2.1-635 Difference
Power and efficiency
Rated power 275 Wp 635 Wp +360 W for 2.1-635
Module efficiency 22.89 % 23.50 % +0.61 pp for 2.1-635
Power density 228.9 Wp/m² 235.1 Wp/m² +6.1 Wp/m² for 2.1-635
Open-circuit voltage 23.89 V 49.60 V 25.71 V apart
Voltage at max power 20.36 V 41.24 V 20.88 V apart
Short-circuit current 14.65 A 16.26 A 1.61 A apart
Current at max power 13.51 A 15.40 A 1.89 A apart
Temperature
Temperature coefficient -0.260 %/°C -0.280 %/°C +0.020 %/°C for 1.2-275
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 1.2-275
Weight per kWp 52.0 kg/kWp 51.2 kg/kWp Effectively the same
Warranty and degradation
Product warranty 30 yrs 12 yrs +18 yrs for 1.2-275
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.45 %/yr 0.45 %/yr Same
Technology
Cell technology Back Contact N-type Back Contact vs N-type
Cell type Monocrystalline Monocrystalline Same
Cell count 64 132 68 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,129 panels
Efficiency
#2,574 vs #749
2.1-635 leads by 1,825 places
Power density
#2,488 vs #777
2.1-635 leads by 1,711 places
Heat behaviour
#515 vs #1,347
1.2-275 leads by 832 places
Weight
#5,449 vs #4,581
2.1-635 leads by 868 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#10,278 vs #1,760
2.1-635 leads by 8,518 places
05

More useful comparisons

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The same specification on paper
06

Written summary

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07

Questions about this pairing

Which panel is better: Heckert Solar ZEUS 1.2-275 or Heckert Solar ZEUS 2.1-635?
According to our database: Heckert Solar ZEUS 2.1-635 has higher module efficiency (23.50% vs 22.89%); Heckert Solar ZEUS 1.2-275 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 1.2-275 and Heckert Solar ZEUS 2.1-635?
Heckert Solar ZEUS 1.2-275 has a module efficiency of 22.89%, while Heckert Solar ZEUS 2.1-635 is 23.50%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Heckert Solar ZEUS 1.2-275 use vs Heckert Solar ZEUS 2.1-635?
Heckert Solar ZEUS 1.2-275 uses Back Contact cells; Heckert Solar ZEUS 2.1-635 uses N-type. 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 1.2-275 and Heckert Solar ZEUS 2.1-635?
Heckert Solar ZEUS 1.2-275 has a 30 years power warranty; Heckert Solar ZEUS 2.1-635 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 1.2-275 and Heckert Solar ZEUS 2.1-635 bifacial panels?
Both Heckert Solar ZEUS 1.2-275 and Heckert Solar ZEUS 2.1-635 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.