--- title: "Longi Solar LR7-72HVHF-670M vs Longi Solar LR8-66HGD-625M - Solar Panel Comparison | ComparePV" description: "Compare Longi Solar LR7-72HVHF-670M vs Longi Solar LR8-66HGD-625M side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr8-66hgd-625m" image: "https://comparepv.com/og/compare/panels/longi-lr7-72hvhf-670m/longi-lr8-66hgd-625m.png" updated: 2026-09-11 --- # Longi Solar LR7-72HVHF-670M vs Longi Solar LR8-66HGD-625M LR7-72HVHF-670M leads on the differences that matter The largest is module efficiency: 1.70 pp more efficient. 5 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | [Longi Solar LR8-66HGD-625M](https://comparepv.com/panel/longi-lr8-66hgd-625m) | | Manufacturer | Longi Solar | Longi Solar | | Power | 670 Wp | 625 Wp | | Efficiency | 24.80 % | 23.10 % | | Technology | N-type | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | LR7-72HVHF-670M | LR8-66HGD-625M | Difference | | --- | --- | --- | --- | | Module efficiency | 24.80 % | 23.10 % | +1.70 pp for LR7-72HVHF-670M | | Rated power | 670 Wp | 625 Wp | +45 W for LR7-72HVHF-670M | | Power density | 248.0 Wp/m² | 231.4 Wp/m² | +16.7 Wp/m² for LR7-72HVHF-670M | | Weight | 28.5 kg | 32.5 kg | -4.0 kg for LR7-72HVHF-670M | | Weight per kWp | 42.5 kg/kWp | 52.0 kg/kWp | -9.5 kg/kWp for LR7-72HVHF-670M | | Temperature coefficient | -0.260 %/°C | -0.280 %/°C | +0.020 %/°C for LR7-72HVHF-670M | | Product warranty | 15 yrs | 12 yrs | +3 yrs for LR7-72HVHF-670M | | Open-circuit voltage | 54.30 V | 48.98 V | 5.32 V apart | | Cell technology | N-type | Back Contact | N-type vs Back Contact | | Annual degradation | 0.35 %/yr | 0.40 %/yr | -0.05 %/yr for LR7-72HVHF-670M | | Cell count | 144 | 132 | 12 cells apart | | Voltage at max power | 44.96 V | 41.11 V | 3.85 V apart | | Bifacial | No | Yes | No vs Yes | | Short-circuit current | 15.60 A | 16.10 A | 0.50 A apart | ## Every compared parameter | Parameter | LR7-72HVHF-670M | LR8-66HGD-625M | | --- | --- | --- | | Rated power | 670 Wp | 625 Wp | | Module efficiency | 24.80 % | 23.10 % | | Power density | 248.0 Wp/m² | 231.4 Wp/m² | | Open-circuit voltage | 54.30 V | 48.98 V | | Voltage at max power | 44.96 V | 41.11 V | | Short-circuit current | 15.60 A | 16.10 A | | Current at max power | 14.91 A | 15.21 A | | Temperature coefficient | -0.260 %/°C | -0.280 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 28.5 kg | 32.5 kg | | Weight per kWp | 42.5 kg/kWp | 52.0 kg/kWp | | Product warranty | 15 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.35 %/yr | 0.40 %/yr | | Cell technology | N-type | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 144 | 132 | | Bifacial | No | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, LR7-72HVHF-670M:** 22,655 kWh - **Cumulative output, LR8-66HGD-625M:** 20,970 kWh - **Gap:** 1,685 kWh ## Output when hot | Condition | Cell temperature | LR7-72HVHF-670M | LR8-66HGD-625M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 670 W | 625 W | 100.0% of rated power | | Cool, bright day | 40 °C | 644 W | 599 W | 95.8% of rated power | | Typical summer roof | 55 °C | 618 W | 573 W | 91.6% of rated power | | Hot roof | 70 °C | 592 W | 546 W | 87.4% of rated power | ## Against the whole database | Measure | LR7-72HVHF-670M | LR8-66HGD-625M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #13 | #1,617 | 14,129 | LR7-72HVHF-670M leads by 1,604 places | | Power density | #15 | #1,558 | 14,129 | LR7-72HVHF-670M leads by 1,543 places | | Heat behaviour | #515 | #1,347 | 14,129 | LR7-72HVHF-670M leads by 832 places | | Weight | #226 | #5,449 | 14,129 | LR7-72HVHF-670M leads by 5,223 places | | Warranty | #21 | #21 | 14,129 | Tied - the same position in the database | | Overall | #285 | #2,293 | 14,129 | LR7-72HVHF-670M leads by 2,008 places | ## Questions ### Which panel is better: Longi Solar LR7-72HVHF-670M or Longi Solar LR8-66HGD-625M? According to our database: **Longi Solar LR7-72HVHF-670M** has higher module efficiency (**24.80%** vs **23.10%**); **Longi Solar LR7-72HVHF-670M** tolerates heat better (temp coeff **-0.260%/°C** vs **-0.280%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Longi Solar LR7-72HVHF-670M and Longi Solar LR8-66HGD-625M? **Longi Solar LR7-72HVHF-670M** has a module efficiency of **24.80%**, while **Longi Solar LR8-66HGD-625M** is **23.10%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Longi Solar LR7-72HVHF-670M use vs Longi Solar LR8-66HGD-625M? **Longi Solar LR7-72HVHF-670M** uses **N-type** cells; **Longi Solar LR8-66HGD-625M** 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 LR7-72HVHF-670M and Longi Solar LR8-66HGD-625M? **Longi Solar LR7-72HVHF-670M** has a **30 years** power warranty; **Longi Solar LR8-66HGD-625M** 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 LR7-72HVHF-670M and Longi Solar LR8-66HGD-625M bifacial panels? **Longi Solar LR8-66HGD-625M** is bifacial (captures light from both faces); **Longi Solar LR7-72HVHF-670M** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Longi Solar LR7-72HVHF-670M vs Longi Solar LR7-72HVHF-665M](https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr7-72hvhf-665m) - One difference: module efficiency - [Longi Solar LR7-72HVHF-670M vs Longi Solar LR7-72HVHF-660M](https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr7-72hvhf-660m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HVHF-670M vs Longi Solar LR7-72HVHF-655M](https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr7-72hvhf-655m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HVHF-670M vs Longi Solar LR7-72HVHF-650M](https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr7-72hvhf-650m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HVHF-670M vs Longi Solar LR7-72HVHF-645M](https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr7-72hvhf-645m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HVHF-670M vs Longi Solar LR7-72HVHF-640M](https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr7-72hvhf-640m) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/longi-lr7-72hvhf-670m/longi-lr8-66hgd-625m 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.