--- title: "Longi Solar LR7-60HVH-540M vs Longi Solar LR8-66HYD-670M - Solar Panel Comparison | ComparePV" description: "Compare Longi Solar LR7-60HVH-540M 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-lr7-60hvh-540m/longi-lr8-66hyd-670m" updated: 2026-09-11 --- # Longi Solar LR7-60HVH-540M vs Longi Solar LR8-66HYD-670M LR8-66HYD-670M leads on the differences that matter The largest is module efficiency: 0.90 pp more efficient. 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 LR7-60HVH-540M](https://comparepv.com/panel/longi-lr7-60hvh-540m) | [Longi Solar LR8-66HYD-670M](https://comparepv.com/panel/longi-lr8-66hyd-670m) | | Manufacturer | Longi Solar | Longi Solar | | Power | 540 Wp | 670 Wp | | Efficiency | 23.90 % | 24.80 % | | Technology | N-type | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | LR7-60HVH-540M | LR8-66HYD-670M | Difference | | --- | --- | --- | --- | | Module efficiency | 23.90 % | 24.80 % | +0.90 pp for LR8-66HYD-670M | | Rated power | 540 Wp | 670 Wp | +130 W for LR8-66HYD-670M | | Weight | 25.0 kg | 33.5 kg | -8.5 kg for LR7-60HVH-540M | | Power density | 239.3 Wp/m² | 248.0 Wp/m² | +8.7 Wp/m² for LR8-66HYD-670M | | Product warranty | 15 yrs | 12 yrs | +3 yrs for LR7-60HVH-540M | | Open-circuit voltage | 44.88 V | 50.12 V | 5.24 V apart | | Module area | 2.257 m² | 2.701 m² | 0.445 m² apart | | Short-circuit current | 15.25 A | 16.86 A | 1.61 A apart | | Weight per kWp | 46.3 kg/kWp | 50.0 kg/kWp | -3.7 kg/kWp for LR7-60HVH-540M | | Cell technology | N-type | Back Contact | N-type vs Back Contact | | Voltage at max power | 37.11 V | 41.38 V | 4.27 V apart | | Cell count | 120 | 132 | 12 cells apart | | Current at max power | 14.55 A | 16.19 A | 1.64 A apart | | Bifacial | No | Yes | No vs Yes | | Dimensions | 1990x1134x30 mm | 2382x1134x30 mm | 1990x1134x30 mm vs 2382x1134x30 mm | ## Every compared parameter | Parameter | LR7-60HVH-540M | LR8-66HYD-670M | | --- | --- | --- | | Rated power | 540 Wp | 670 Wp | | Module efficiency | 23.90 % | 24.80 % | | Power density | 239.3 Wp/m² | 248.0 Wp/m² | | Open-circuit voltage | 44.88 V | 50.12 V | | Voltage at max power | 37.11 V | 41.38 V | | Short-circuit current | 15.25 A | 16.86 A | | Current at max power | 14.55 A | 16.19 A | | Temperature coefficient | -0.260 %/°C | -0.260 %/°C | | Dimensions | 1990x1134x30 mm | 2382x1134x30 mm | | Module area | 2.257 m² | 2.701 m² | | Weight | 25.0 kg | 33.5 kg | | Weight per kWp | 46.3 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 | 120 | 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, LR7-60HVH-540M:** 18,118 kWh - **Cumulative output, LR8-66HYD-670M:** 22,480 kWh - **Gap:** 4,362 kWh ## Output when hot | Condition | Cell temperature | LR7-60HVH-540M | LR8-66HYD-670M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 540 W | 670 W | 100.0% of rated power | | Cool, bright day | 40 °C | 519 W | 644 W | 96.1% of rated power | | Typical summer roof | 55 °C | 498 W | 618 W | 92.2% of rated power | | Hot roof | 70 °C | 477 W | 592 W | 88.3% of rated power | ## Against the whole database | Measure | LR7-60HVH-540M | LR8-66HYD-670M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #351 | #12 | 14,005 | LR8-66HYD-670M leads by 339 places | | Power density | #353 | #14 | 14,005 | LR8-66HYD-670M leads by 339 places | | Heat behaviour | #511 | #511 | 14,005 | Tied - the same position in the database | | Weight | #1,110 | #3,317 | 14,005 | LR7-60HVH-540M leads by 2,207 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #3,521 | #490 | 14,005 | LR8-66HYD-670M leads by 3,031 places | ## Questions ### Which panel is better: Longi Solar LR7-60HVH-540M or Longi Solar LR8-66HYD-670M? According to our database: **Longi Solar LR8-66HYD-670M** has higher module efficiency (**24.80%** vs **23.90%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Longi Solar LR7-60HVH-540M and Longi Solar LR8-66HYD-670M? **Longi Solar LR7-60HVH-540M** has a module efficiency of **23.90%**, 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 LR7-60HVH-540M use vs Longi Solar LR8-66HYD-670M? **Longi Solar LR7-60HVH-540M** 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 LR7-60HVH-540M and Longi Solar LR8-66HYD-670M? **Longi Solar LR7-60HVH-540M** 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 LR7-60HVH-540M and Longi Solar LR8-66HYD-670M bifacial panels? **Longi Solar LR8-66HYD-670M** is bifacial (captures light from both faces); **Longi Solar LR7-60HVH-540M** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Longi Solar LR7-60HVH-540M vs Longi Solar LR7-60HVH-560M](https://comparepv.com/compare/longi-lr7-60hvh-540m/longi-lr7-60hvh-560m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-60HVH-540M vs Longi Solar LR7-60HVH-555M](https://comparepv.com/compare/longi-lr7-60hvh-540m/longi-lr7-60hvh-555m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-60HVH-540M vs Longi Solar LR7-60HVH-550M](https://comparepv.com/compare/longi-lr7-60hvh-540m/longi-lr7-60hvh-550m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-60HVH-540M vs Longi Solar LR7-60HVH-545M](https://comparepv.com/compare/longi-lr7-60hvh-540m/longi-lr7-60hvh-545m) - One difference: module efficiency - [Longi Solar LR7-60HVH-540M vs Longi Solar LR7-60HVH-535M](https://comparepv.com/compare/longi-lr7-60hvh-540m/longi-lr7-60hvh-535m) - One difference: 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 --- Source: https://comparepv.com/compare/longi-lr7-60hvh-540m/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.