--- title: "Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-545M - Solar Panel Comparison | ComparePV" description: "Compare Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-545M side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/longi-lr5-66hph-500m/longi-lr5-72hph-545m" updated: 2026-09-11 --- # Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-545M 72HPH-545M leads on the differences that matter The largest is rated power: 45 W more power. 10 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Longi Solar LR5-66HPH-500M](https://comparepv.com/panel/longi-lr5-66hph-500m) | [Longi Solar LR5-72HPH-545M](https://comparepv.com/panel/longi-lr5-72hph-545m) | | Manufacturer | Longi Solar | Longi Solar | | Power | 500 Wp | 545 Wp | | Efficiency | 21.30 % | 21.10 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 66HPH-500M | 72HPH-545M | Difference | | --- | --- | --- | --- | | Rated power | 500 Wp | 545 Wp | +45 W for 72HPH-545M | | Open-circuit voltage | 45.55 V | 49.65 V | 4.10 V apart | | Module area | 2.349 m² | 2.583 m² | 0.235 m² apart | | Weight | 25.1 kg | 27.5 kg | -2.4 kg for 66HPH-500M | | Module efficiency | 21.30 % | 21.10 % | +0.20 pp for 66HPH-500M | | Temperature coefficient | -0.350 %/°C | -0.340 %/°C | +0.010 %/°C for 72HPH-545M | | Cell count | 132 | 144 | 12 cells apart | | Voltage at max power | 38.38 V | 41.80 V | 3.42 V apart | | Dimensions | 2073x1133x35 mm | 2278x1134x35 mm | 2073x1133x35 mm vs 2278x1134x35 mm | ## Every compared parameter | Parameter | 66HPH-500M | 72HPH-545M | | --- | --- | --- | | Rated power | 500 Wp | 545 Wp | | Module efficiency | 21.30 % | 21.10 % | | Power density | 212.9 Wp/m² | 211.0 Wp/m² | | Open-circuit voltage | 45.55 V | 49.65 V | | Voltage at max power | 38.38 V | 41.80 V | | Short-circuit current | 13.90 A | 13.92 A | | Current at max power | 13.03 A | 13.04 A | | Temperature coefficient | -0.350 %/°C | -0.340 %/°C | | Dimensions | 2073x1133x35 mm | 2278x1134x35 mm | | Module area | 2.349 m² | 2.583 m² | | Weight | 25.1 kg | 27.5 kg | | Weight per kWp | 50.2 kg/kWp | 50.5 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 25 yrs | 25 yrs | | Annual degradation | 0.55 %/yr | 0.55 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 144 | | Bifacial | No | No | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, 66HPH-500M:** 16,205 kWh - **Cumulative output, 72HPH-545M:** 17,663 kWh - **Gap:** 1,458 kWh ## Output when hot | Condition | Cell temperature | 66HPH-500M | 72HPH-545M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 500 W | 545 W | 100.0% of rated power | | Cool, bright day | 40 °C | 474 W | 517 W | 94.8% of rated power | | Typical summer roof | 55 °C | 448 W | 489 W | 89.5% of rated power | | Hot roof | 70 °C | 421 W | 462 W | 84.2% of rated power | ## Against the whole database | Measure | 66HPH-500M | 72HPH-545M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #8,519 | #9,297 | 14,005 | 66HPH-500M leads by 778 places | | Power density | #8,599 | #9,312 | 14,005 | 66HPH-500M leads by 713 places | | Heat behaviour | #10,419 | #8,778 | 14,005 | 72HPH-545M leads by 1,641 places | | Weight | #3,664 | #3,832 | 14,005 | 66HPH-500M leads by 168 places | | Warranty | #9,798 | #9,798 | 14,005 | Tied - the same position in the database | | Overall | #9,679 | #8,467 | 14,005 | 72HPH-545M leads by 1,212 places | ## Questions ### Which panel is better: Longi Solar LR5-66HPH-500M or Longi Solar LR5-72HPH-545M? According to our database: **Longi Solar LR5-66HPH-500M** has higher module efficiency (**21.30%** vs **21.10%**); **Longi Solar LR5-72HPH-545M** tolerates heat better (temp coeff **-0.340%/°C** vs **-0.350%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Longi Solar LR5-66HPH-500M and Longi Solar LR5-72HPH-545M? **Longi Solar LR5-66HPH-500M** has a module efficiency of **21.30%**, while **Longi Solar LR5-72HPH-545M** is **21.10%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Longi Solar LR5-66HPH-500M use vs Longi Solar LR5-72HPH-545M? **Longi Solar LR5-66HPH-500M** uses **PERC** cells; **Longi Solar LR5-72HPH-545M** uses **PERC**. 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 LR5-66HPH-500M and Longi Solar LR5-72HPH-545M? **Longi Solar LR5-66HPH-500M** has a **25 years** power warranty; **Longi Solar LR5-72HPH-545M** has a **25 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. ## Related comparisons - [Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-565M](https://comparepv.com/compare/longi-lr5-66hph-500m/longi-lr5-72hph-565m) - 10 differences, the largest is rated power - [Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-560M](https://comparepv.com/compare/longi-lr5-66hph-500m/longi-lr5-72hph-560m) - 10 differences, the largest is rated power - [Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-555M](https://comparepv.com/compare/longi-lr5-66hph-500m/longi-lr5-72hph-555m) - 9 differences, the largest is rated power - [Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-550M](https://comparepv.com/compare/longi-lr5-66hph-500m/longi-lr5-72hph-550m) - 8 differences, the largest is rated power - [Longi Solar LR5-66HPH-500M vs Longi Solar LR5-66HPH-515M](https://comparepv.com/compare/longi-lr5-66hph-500m/longi-green-energy-technology-co-ltd-lr5-66hph-515m) - 6 differences, the largest is module efficiency - [Longi Solar LR5-66HPH-500M vs Longi Solar LR5-66HPH-510M](https://comparepv.com/compare/longi-lr5-66hph-500m/longi-green-energy-technology-co-ltd-lr5-66hph-510m) - 5 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/longi-lr5-66hph-500m/longi-lr5-72hph-545m 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.