--- title: "Longi Solar LR7-54HVH-500M vs Longi Solar LR8-66HYD-670M - Solar Panel Comparison | ComparePV" description: "Compare Longi Solar LR7-54HVH-500M vs Longi Solar LR8-66HYD-670M side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/longi-lr7-54hvh-500m/longi-lr8-66hyd-670m" updated: 2026-09-11 --- # Longi Solar LR7-54HVH-500M vs Longi Solar LR8-66HYD-670M 15 differences, and they point both ways The largest is rated power: 170 W more power. 3 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Longi Solar LR7-54HVH-500M](https://comparepv.com/panel/longi-lr7-54hvh-500m) | [Longi Solar LR8-66HYD-670M](https://comparepv.com/panel/longi-lr8-66hyd-670m) | | Manufacturer | Longi Solar | Longi Solar | | Power | 500 Wp | 670 Wp | | Efficiency | 24.50 % | 24.80 % | | Technology | N-type | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | LR7-54HVH-500M | LR8-66HYD-670M | Difference | | --- | --- | --- | --- | | Rated power | 500 Wp | 670 Wp | +170 W for LR8-66HYD-670M | | Weight | 21.6 kg | 33.5 kg | -11.9 kg for LR7-54HVH-500M | | Weight per kWp | 43.2 kg/kWp | 50.0 kg/kWp | -6.8 kg/kWp for LR7-54HVH-500M | | Product warranty | 15 yrs | 12 yrs | +3 yrs for LR7-54HVH-500M | | Open-circuit voltage | 40.75 V | 50.12 V | 9.37 V apart | | Module area | 2.041 m² | 2.701 m² | 0.660 m² apart | | Module efficiency | 24.50 % | 24.80 % | +0.30 pp for LR8-66HYD-670M | | Short-circuit current | 15.53 A | 16.86 A | 1.33 A apart | | Cell technology | N-type | Back Contact | N-type vs Back Contact | | Power density | 245.0 Wp/m² | 248.0 Wp/m² | +3.1 Wp/m² for LR8-66HYD-670M | | Voltage at max power | 33.73 V | 41.38 V | 7.65 V apart | | Cell count | 108 | 132 | 24 cells apart | | Bifacial | No | Yes | No vs Yes | | Current at max power | 14.83 A | 16.19 A | 1.36 A apart | | Dimensions | 1800x1134x30 mm | 2382x1134x30 mm | 1800x1134x30 mm vs 2382x1134x30 mm | ## Every compared parameter | Parameter | LR7-54HVH-500M | LR8-66HYD-670M | | --- | --- | --- | | Rated power | 500 Wp | 670 Wp | | Module efficiency | 24.50 % | 24.80 % | | Power density | 245.0 Wp/m² | 248.0 Wp/m² | | Open-circuit voltage | 40.75 V | 50.12 V | | Voltage at max power | 33.73 V | 41.38 V | | Short-circuit current | 15.53 A | 16.86 A | | Current at max power | 14.83 A | 16.19 A | | Temperature coefficient | -0.260 %/°C | -0.260 %/°C | | Dimensions | 1800x1134x30 mm | 2382x1134x30 mm | | Module area | 2.041 m² | 2.701 m² | | Weight | 21.6 kg | 33.5 kg | | Weight per kWp | 43.2 kg/kWp | 50.0 kg/kWp | | Product warranty | 15 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.35 %/yr | - | | Cell technology | N-type | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 108 | 132 | | Bifacial | No | Yes | ## Thirty-year yield A 1.0% first-year loss then 0.40% a year, assumed for both panels, 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, LR7-54HVH-500M:** 16,776 kWh - **Cumulative output, LR8-66HYD-670M:** 22,480 kWh - **Gap:** 5,704 kWh ## Output when hot | Condition | Cell temperature | LR7-54HVH-500M | LR8-66HYD-670M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 500 W | 670 W | 100.0% of rated power | | Cool, bright day | 40 °C | 481 W | 644 W | 96.1% of rated power | | Typical summer roof | 55 °C | 461 W | 618 W | 92.2% of rated power | | Hot roof | 70 °C | 442 W | 592 W | 88.3% of rated power | ## Against the whole database | Measure | LR7-54HVH-500M | LR8-66HYD-670M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #74 | #12 | 14,005 | LR8-66HYD-670M leads by 62 places | | Power density | #77 | #14 | 14,005 | LR8-66HYD-670M leads by 63 places | | Heat behaviour | #511 | #511 | 14,005 | Tied - the same position in the database | | Weight | #274 | #3,317 | 14,005 | LR7-54HVH-500M leads by 3,043 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #4,105 | #490 | 14,005 | LR8-66HYD-670M leads by 3,615 places | ## Questions ### Which panel is better: Longi Solar LR7-54HVH-500M or Longi Solar LR8-66HYD-670M? According to our database: **Longi Solar LR8-66HYD-670M** has higher module efficiency (**24.80%** vs **24.50%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Longi Solar LR7-54HVH-500M and Longi Solar LR8-66HYD-670M? **Longi Solar LR7-54HVH-500M** has a module efficiency of **24.50%**, while **Longi Solar LR8-66HYD-670M** is **24.80%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Longi Solar LR7-54HVH-500M use vs Longi Solar LR8-66HYD-670M? **Longi Solar LR7-54HVH-500M** uses **N-type** cells; **Longi Solar LR8-66HYD-670M** 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 Longi Solar LR7-54HVH-500M and Longi Solar LR8-66HYD-670M? **Longi Solar LR7-54HVH-500M** has a **30 years** power warranty; **Longi Solar LR8-66HYD-670M** 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 Longi Solar LR7-54HVH-500M and Longi Solar LR8-66HYD-670M bifacial panels? **Longi Solar LR8-66HYD-670M** is bifacial (captures light from both faces); **Longi Solar LR7-54HVH-500M** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Longi Solar LR7-54HVH-500M vs Longi Solar LR7-54HVH-495M](https://comparepv.com/compare/longi-lr7-54hvh-500m/longi-lr7-54hvh-495m) - One difference: module efficiency - [Longi Solar LR7-54HVH-500M vs Longi Solar LR7-54HVH-490M](https://comparepv.com/compare/longi-lr7-54hvh-500m/longi-lr7-54hvh-490m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-54HVH-500M vs Longi Solar LR7-54HVH-485M](https://comparepv.com/compare/longi-lr7-54hvh-500m/longi-lr7-54hvh-485m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-54HVH-500M vs Longi Solar LR7-54HVH-480M](https://comparepv.com/compare/longi-lr7-54hvh-500m/longi-lr7-54hvh-480m) - 3 differences, the largest is module efficiency - [Longi Solar LR8-66HYD-670M vs Longi Solar LR8-66HYD-665M](https://comparepv.com/compare/longi-lr8-66hyd-670m/longi-lr8-66hyd-665m) - One difference: module efficiency - [Longi Solar LR8-66HYD-670M vs Longi Solar LR8-66HYD-660M](https://comparepv.com/compare/longi-lr8-66hyd-670m/longi-solar-lr8-66hyd-660m) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/longi-lr7-54hvh-500m/longi-lr8-66hyd-670m 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.