--- title: "Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 1.2-280 - Solar Panel Comparison | ComparePV" description: "Compare Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 1.2-280 side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-1-2-280" updated: 2026-09-13 --- # Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 1.2-280 280 leads on the differences that matter The largest is module efficiency: 0.42 pp more efficient. 17 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Heckert Solar ZEUS 1.2-275](https://comparepv.com/panel/heckert-solar-zeus-1-2-275) | [Heckert Solar ZEUS 1.2-280](https://comparepv.com/panel/heckert-solar-zeus-1-2-280) | | Manufacturer | Heckert Solar | Heckert Solar | | Power | 275 Wp | 280 Wp | | Efficiency | 22.89 % | 23.31 % | | Technology | Back Contact | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 275 | 280 | Difference | | --- | --- | --- | --- | | Module efficiency | 22.89 % | 23.31 % | +0.42 pp for 280 | | Power density | 228.9 Wp/m² | 233.1 Wp/m² | +4.2 Wp/m² for 280 | ## Every compared parameter | Parameter | 275 | 280 | | --- | --- | --- | | Rated power | 275 Wp | 280 Wp | | Module efficiency | 22.89 % | 23.31 % | | Power density | 228.9 Wp/m² | 233.1 Wp/m² | | Open-circuit voltage | 23.89 V | 24.11 V | | Voltage at max power | 20.36 V | 20.49 V | | Short-circuit current | 14.65 A | 14.72 A | | Current at max power | 13.51 A | 13.67 A | | Temperature coefficient | -0.260 %/°C | -0.260 %/°C | | Dimensions | 1560x770x35 mm | 1560x770x35 mm | | Module area | 1.201 m² | 1.201 m² | | Weight | 14.3 kg | 14.3 kg | | Weight per kWp | 52.0 kg/kWp | 51.1 kg/kWp | | Product warranty | 30 yrs | 30 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.45 %/yr | 0.45 %/yr | | Cell technology | Back Contact | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 64 | 64 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.260 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other. - **Cumulative output, 275:** 9,056 kWh - **Cumulative output, 280:** 9,221 kWh - **Gap:** 165 kWh ## Output when hot | Condition | Cell temperature | 275 | 280 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 275 W | 280 W | 100.0% of rated power | | Cool, bright day | 40 °C | 264 W | 269 W | 96.1% of rated power | | Typical summer roof | 55 °C | 254 W | 258 W | 92.2% of rated power | | Hot roof | 70 °C | 243 W | 247 W | 88.3% of rated power | ## Against the whole database | Measure | 275 | 280 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #2,490 | #1,004 | 13,953 | 280 leads by 1,486 places | | Power density | #2,404 | #1,084 | 13,953 | 280 leads by 1,320 places | | Heat behaviour | #511 | #511 | 13,953 | Tied - the same position in the database | | Weight | #5,386 | #4,382 | 13,953 | 280 leads by 1,004 places | | Warranty | #21 | #21 | 13,953 | Tied - the same position in the database | | Overall | #10,137 | #9,692 | 13,953 | 280 leads by 445 places | ## Questions ### Which panel is better: Heckert Solar ZEUS 1.2-275 or Heckert Solar ZEUS 1.2-280? According to our database: **Heckert Solar ZEUS 1.2-280** has higher module efficiency (**23.31%** vs **22.89%**). 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 1.2-280? **Heckert Solar ZEUS 1.2-275** has a module efficiency of **22.89%**, 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 1.2-275 use vs Heckert Solar ZEUS 1.2-280? **Heckert Solar ZEUS 1.2-275** uses **Back Contact** 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 1.2-275 and Heckert Solar ZEUS 1.2-280? **Heckert Solar ZEUS 1.2-275** 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 1.2-275 and Heckert Solar ZEUS 1.2-280 bifacial panels? Both **Heckert Solar ZEUS 1.2-275** 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. ## Related comparisons - [Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 2.1-640](https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-2-1-640) - 14 differences, the largest is module efficiency - [Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 2.1 640W](https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-2-1-640w) - 14 differences, the largest is module efficiency - [Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 2.1-635](https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-2-1-635) - 14 differences, the largest is rated power - [Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 2.1 635W](https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-2-1-635w) - 14 differences, the largest is rated power - [Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 1.2 FullBlack 280W](https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-1-2-fullblack-280w) - 2 differences, the largest is module efficiency - [Heckert Solar ZEUS 1.2-275 vs Heckert Solar ZEUS 1.2 FullBlack 275W](https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-1-2-fullblack-275w) - The same specification on paper --- Source: https://comparepv.com/compare/heckert-solar-zeus-1-2-275/heckert-solar-zeus-1-2-280 Not in this file, on the page: the thirty-year yield curve year by year at a cell temperature you pick and a written summary generated on request.