--- title: "Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-620M - Solar Panel Comparison | ComparePV" description: "Compare Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-620M side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72htdr-620m" updated: 2026-09-11 --- # Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-620M 620M leads on the differences that matter The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Longi Solar LR7-72HTDR-615M](https://comparepv.com/panel/longi-lr7-72htdr-615m) | [Longi Solar LR7-72HTDR-620M](https://comparepv.com/panel/longi-lr7-72htdr-620m) | | Manufacturer | Longi Solar | Longi Solar | | Power | 615 Wp | 620 Wp | | Efficiency | 22.80 % | 23.00 % | | Technology | N-type | N-type | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 615M | 620M | Difference | | --- | --- | --- | --- | | Module efficiency | 22.80 % | 23.00 % | +0.20 pp for 620M | ## Every compared parameter | Parameter | 615M | 620M | | --- | --- | --- | | Rated power | 615 Wp | 620 Wp | | Module efficiency | 22.80 % | 23.00 % | | Power density | 227.7 Wp/m² | 229.5 Wp/m² | | Open-circuit voltage | 52.96 V | 53.11 V | | Voltage at max power | 44.63 V | 44.78 V | | Short-circuit current | 14.75 A | 14.82 A | | Current at max power | 13.78 A | 13.85 A | | Temperature coefficient | -0.280 %/°C | -0.280 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 33.5 kg | 33.5 kg | | Weight per kWp | 54.5 kg/kWp | 54.0 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.35 %/yr | 0.35 %/yr | | Cell technology | N-type | N-type | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 144 | 144 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.280 %/°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, 615M:** 20,795 kWh - **Cumulative output, 620M:** 20,964 kWh - **Gap:** 169 kWh ## Output when hot | Condition | Cell temperature | 615M | 620M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 615 W | 620 W | 100.0% of rated power | | Cool, bright day | 40 °C | 589 W | 594 W | 95.8% of rated power | | Typical summer roof | 55 °C | 563 W | 568 W | 91.6% of rated power | | Hot roof | 70 °C | 538 W | 542 W | 87.4% of rated power | ## Against the whole database | Measure | 615M | 620M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #2,714 | #1,919 | 14,005 | 620M leads by 795 places | | Power density | #3,077 | #2,191 | 14,005 | 620M leads by 886 places | | Heat behaviour | #1,309 | #1,309 | 14,005 | Tied - the same position in the database | | Weight | #8,815 | #8,248 | 14,005 | 620M leads by 567 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #2,350 | #2,048 | 14,005 | 620M leads by 302 places | ## Questions ### Which panel is better: Longi Solar LR7-72HTDR-615M or Longi Solar LR7-72HTDR-620M? According to our database: **Longi Solar LR7-72HTDR-620M** has higher module efficiency (**23.00%** vs **22.80%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Longi Solar LR7-72HTDR-615M and Longi Solar LR7-72HTDR-620M? **Longi Solar LR7-72HTDR-615M** has a module efficiency of **22.80%**, while **Longi Solar LR7-72HTDR-620M** is **23.00%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Longi Solar LR7-72HTDR-615M use vs Longi Solar LR7-72HTDR-620M? **Longi Solar LR7-72HTDR-615M** uses **N-type** cells; **Longi Solar LR7-72HTDR-620M** uses **N-type**. 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 LR7-72HTDR-615M and Longi Solar LR7-72HTDR-620M? **Longi Solar LR7-72HTDR-615M** has a **30 years** power warranty; **Longi Solar LR7-72HTDR-620M** 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 LR7-72HTDR-615M and Longi Solar LR7-72HTDR-620M bifacial panels? Both **Longi Solar LR7-72HTDR-615M** and **Longi Solar LR7-72HTDR-620M** are bifacial - they capture reflected light from the ground, which can add 5**-15%** more annual energy on ground-mount or elevated rooftop installations with a light surface beneath. ## Related comparisons - [Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-625M](https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72htdr-625m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-610M](https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72htdr-610m) - One difference: module efficiency - [Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-605M](https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72htdr-605m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HTDR-600M](https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72htdr-600m) - 3 differences, the largest is module efficiency - [Longi Solar LR7-72HTDR-615M vs Longi Solar LR7-72HVHF-670M](https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72hvhf-670m) - 10 differences, the largest is module efficiency - [Longi Solar LR7-72HTDR-615M vs Longi Solar LR8-66HYD-670M](https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr8-66hyd-670m) - 12 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/longi-lr7-72htdr-615m/longi-lr7-72htdr-620m 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.