--- title: "Longi Solar LR5-72HTH-575M vs Longi Solar LR8-66HYD-670M - Solar Panel Comparison | ComparePV" description: "Compare Longi Solar LR5-72HTH-575M 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-lr5-72hth-575m/longi-lr8-66hyd-670m" image: "https://comparepv.com/og/compare/panels/longi-lr5-72hth-575m/longi-lr8-66hyd-670m.png" updated: 2026-09-11 --- # Longi Solar LR5-72HTH-575M vs Longi Solar LR8-66HYD-670M LR8-66HYD-670M leads on the differences that matter The largest is module efficiency: 2.50 pp more efficient. 1 of 17 comparable parameters are identical, with 2 more left out because at least one datasheet does not publish them. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Longi Solar LR5-72HTH-575M](https://comparepv.com/panel/longi-lr5-72hth-575m) | [Longi Solar LR8-66HYD-670M](https://comparepv.com/panel/longi-lr8-66hyd-670m) | | Manufacturer | Longi Solar | Longi Solar | | Power | 575 Wp | 670 Wp | | Efficiency | 22.30 % | 24.80 % | | Technology | | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | LR5-72HTH-575M | LR8-66HYD-670M | Difference | | --- | --- | --- | --- | | Module efficiency | 22.30 % | 24.80 % | +2.50 pp for LR8-66HYD-670M | | Rated power | 575 Wp | 670 Wp | +95 W for LR8-66HYD-670M | | Power density | 222.6 Wp/m² | 248.0 Wp/m² | +25.5 Wp/m² for LR8-66HYD-670M | | Performance warranty | 25 yrs | 30 yrs | +5 yrs for LR8-66HYD-670M | | Temperature coefficient | -0.290 %/°C | -0.260 %/°C | +0.030 %/°C for LR8-66HYD-670M | | Weight | 27.2 kg | 33.5 kg | -6.3 kg for LR5-72HTH-575M | | Product warranty | 15 yrs | 12 yrs | +3 yrs for LR5-72HTH-575M | | Short-circuit current | 14.14 A | 16.86 A | 2.72 A apart | | Module area | 2.583 m² | 2.701 m² | 0.118 m² apart | | Weight per kWp | 47.3 kg/kWp | 50.0 kg/kWp | -2.7 kg/kWp for LR5-72HTH-575M | | Current at max power | 13.10 A | 16.19 A | 3.09 A apart | | Cell count | 144 | 132 | 12 cells apart | | Open-circuit voltage | 52.06 V | 50.12 V | 1.94 V apart | | Bifacial | No | Yes | No vs Yes | | Voltage at max power | 43.91 V | 41.38 V | 2.53 V apart | | Dimensions | 2278x1134x30 mm | 2382x1134x30 mm | 2278x1134x30 mm vs 2382x1134x30 mm | ## Every compared parameter | Parameter | LR5-72HTH-575M | LR8-66HYD-670M | | --- | --- | --- | | Rated power | 575 Wp | 670 Wp | | Module efficiency | 22.30 % | 24.80 % | | Power density | 222.6 Wp/m² | 248.0 Wp/m² | | Open-circuit voltage | 52.06 V | 50.12 V | | Voltage at max power | 43.91 V | 41.38 V | | Short-circuit current | 14.14 A | 16.86 A | | Current at max power | 13.10 A | 16.19 A | | Temperature coefficient | -0.290 %/°C | -0.260 %/°C | | Dimensions | 2278x1134x30 mm | 2382x1134x30 mm | | Module area | 2.583 m² | 2.701 m² | | Weight | 27.2 kg | 33.5 kg | | Weight per kWp | 47.3 kg/kWp | 50.0 kg/kWp | | Product warranty | 15 yrs | 12 yrs | | Performance warranty | 25 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | - | | Cell technology | - | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 144 | 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 - **Cumulative output, LR5-72HTH-575M:** 19,292 kWh - **Cumulative output, LR8-66HYD-670M:** 22,480 kWh - **Gap:** 3,188 kWh ## Output when hot | Condition | Cell temperature | LR5-72HTH-575M | LR8-66HYD-670M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 575 W | 670 W | 100.0% of rated power | | Cool, bright day | 40 °C | 550 W | 644 W | 95.7% of rated power | | Typical summer roof | 55 °C | 525 W | 618 W | 91.3% of rated power | | Hot roof | 70 °C | 500 W | 592 W | 87.0% of rated power | ## Against the whole database | Measure | LR5-72HTH-575M | LR8-66HYD-670M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #5,161 | #13 | 14,129 | LR8-66HYD-670M leads by 5,148 places | | Power density | #5,612 | #15 | 14,129 | LR8-66HYD-670M leads by 5,597 places | | Heat behaviour | #2,220 | #515 | 14,129 | LR8-66HYD-670M leads by 1,705 places | | Weight | #1,627 | #3,329 | 14,129 | LR5-72HTH-575M leads by 1,702 places | | Warranty | #9,912 | #21 | 14,129 | LR8-66HYD-670M leads by 9,891 places | | Overall | #5,221 | #497 | 14,129 | LR8-66HYD-670M leads by 4,724 places | ## Questions ### Which panel is better: Longi Solar LR5-72HTH-575M or Longi Solar LR8-66HYD-670M? According to our database: **Longi Solar LR8-66HYD-670M** has higher module efficiency (**24.80%** vs **22.30%**); **Longi Solar LR8-66HYD-670M** tolerates heat better (temp coeff **-0.260%/°C** vs **-0.290%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Longi Solar LR5-72HTH-575M and Longi Solar LR8-66HYD-670M? **Longi Solar LR5-72HTH-575M** has a module efficiency of **22.30%**, 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 LR5-72HTH-575M use vs Longi Solar LR8-66HYD-670M? **Longi Solar LR5-72HTH-575M** uses Monocrystalline 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 LR5-72HTH-575M and Longi Solar LR8-66HYD-670M? **Longi Solar LR5-72HTH-575M** has a **25 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 LR5-72HTH-575M and Longi Solar LR8-66HYD-670M bifacial panels? **Longi Solar LR8-66HYD-670M** is bifacial (captures light from both faces); **Longi Solar LR5-72HTH-575M** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Longi Solar LR5-72HTH-575M vs Longi Solar LR5-72HTH-585M](https://comparepv.com/compare/longi-lr5-72hth-575m/longi-lr5-72hth-585m) - 3 differences, the largest is module efficiency - [Longi Solar LR5-72HTH-575M vs Longi Solar LR5-72HTH-580M](https://comparepv.com/compare/longi-lr5-72hth-575m/longi-lr5-72hth-580m) - One difference: module efficiency - [Longi Solar LR5-72HTH-575M vs Longi Solar LR5-72HTH-570M](https://comparepv.com/compare/longi-lr5-72hth-575m/longi-lr5-72hth-570m) - One difference: module efficiency - [Longi Solar LR5-72HTH-575M vs Longi Solar LR5-72HTH-565M](https://comparepv.com/compare/longi-lr5-72hth-575m/longi-lr5-72hth-565m) - 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-lr5-72hth-575m/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.