--- title: "Longi Solar LR7-72HVDF-645M 645W Solar Panel - Specs & Review | ComparePV" description: "Longi Solar LR7-72HVDF-645M 645W solar panel. Specs: 23.90% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/longi-lr7-72hvdf-645m" updated: 2026-09-11 --- # Longi Solar LR7-72HVDF-645M Efficiency leader, no clear weak spot 359 panels in the segment N-type 600-650 W ## Identity - **Manufacturer:** Longi Solar - **Model:** LR7-72HVDF-645M - **Series:** Hi-MO X10 Guardian (LR7-72HVDF 640~665M) - **Rated power:** 645 W - **Cell technology:** N-type - **Bifacial:** yes ## How it compares Compared against segment N-type 600-650 W (359 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 645 W | 625 W | Strong - top 3% | | | Module efficiency | 23.90% | 22.77% | Strong - top 2% | 351 | | Power density | 238.8 | 227.7 | Strong - top 2% | 356 | | Temperature coefficient | -0.260 | -0.290 | Strong - top 4% | 511 | | Weight (kg) | 33.5 kg | 32.5 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 23.90% | 22.77% | Strong - top 2% | 351 | | Power density | 238.8 | 227.7 | Strong - top 2% | 356 | | Temperature coefficient | -0.260 | -0.290 | Strong - top 4% | 511 | | Weight per kWp | 51.9 | 52.7 | Typical | 5,361 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **23.90% module efficiency** - Top 2% of the N-type 600-650 W segment, against a median of 22.77%. Ranked 351st in the whole database. - **238.8 watts per square metre** - Top 2% of the N-type 600-650 W segment, against a median of 227.7. Ranked 356th in the whole database. - **-0.260 %/°C temperature coefficient** - Top 4% of the N-type 600-650 W segment, against a median of -0.290. Ranked 511th in the whole database. - **Best for:** Commercial, utility-scale, hot-climate and shaded-installations. ## Specification ### Electrical - **Rated power (Pmax):** 645 W - **Efficiency:** 23.90 % - **Voltage at Pmax (Vmp):** 44.77 V - **Current at Pmax (Imp):** 14.41 A - **Open-circuit voltage (Voc):** 54.12 V - **Short-circuit current (Isc):** 15.06 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.260 %/degC - **Temperature coefficient of Voc:** -0.200 %/degC - **Temperature coefficient of Isc:** 0.050 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** N-type - **Cell count:** 144 - **Bifacial:** yes ### Physical - **Length:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 33.5 kg - **Area:** 2.70 m2 - **Power density:** 238.8 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 88.8 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.35 % - **Output after 30 years:** 573 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 351 of 14005 | | Power density | 356 of 14005 | | Temperature coefficient | 511 of 14005 | | Weight | 5361 of 14005 | | Warranty | 21 of 14005 | ## Pros - **HPBC 2.0 back contact, up to 24.6% efficiency** - The back-contact architecture eliminates front-side busbars, delivering efficiency up to 24.6% - on par with the best peer comparables (Sunpro Power at 24.62%, Talesun at 24.6%) and clearly ahead of Waaree Arka (21.29%). - **Unique anti-dust frame design** - The frame profile that limits dirt buildup along the glass edge is a feature rarely seen among peer comparables. In practice this means slower yield degradation and less frequent module cleaning on PV farms and large C&I roofs in dry or dusty regions. - **Low degradation - 88.85% power at year 30** - A first-year degradation of 1% and a linear annual degradation rate of 0.35% guarantee 88.85% of rated power after 30 years - above the typical 87.4% threshold offered by many tier-1 manufacturers on older TOPCon lines. - **Bifacial N-type module with shading resilience** - The back-contact design reduces losses from partial shading (chimneys, skylights, soiling), while the bifacial module's dual-side operation boosts energy yield from reflected irradiance - relevant for ground-mount and C&I roof installations. - **Longi as a bankable Tier-1 manufacturer** - Longi Solar has operated since 2000 and is classified as a bankable Tier-1 manufacturer, easing financing for large-scale PV projects and increasing confidence in honoring warranty claims over a 15-30 year horizon. ## Cons - **15-year product warranty below 2026 premium standard** - While the 30-year power warranty (88.85% retention) is best-in-class, the 15-year product warranty is notably shorter than competing premium N-type lines in 2026 - JA Solar DeepBlue and Trina Vertex S+, for instance, already offer 25-year product warranties. ## About this series The Longi Solar Hi-MO X10 Guardian (LR7-72HVDF 640-665M) series is engineered to maintain high performance where other modules typically lose efficiency - in dusty conditions, seasonal shading, and at risk of hotspots. The key difference is the **anti-dust frame design**, which minimizes dirt accumulation on the glass edges, thereby reducing performance degradation over time and decreasing the need for cleaning. In practice, this ensures more reliable operation during dry seasons, on sites near roads, industrial facilities, or in polluted areas. The modules feature **back-contact architecture**, which enhances light capture on the front side of the cells and supports energy yield even under challenging exposure conditions. Additionally, the series emphasizes **shade resistance** - experiencing fewer losses from shading caused by chimneys, skylights, obstacles, and pollution. Another important feature is **reduced localized heating**, increasing long-term safety and operational predictability. This makes it an excellent choice for large-scale PV farms and commercial & industrial (C&I) rooftops, where high performance, serviceability, and lower energy costs over the lifetime are key priorities. ## Notable figures - At 23.9% efficiency, this panel is 1.1pp above typical \*\*N-type 600-650W\*\* modules (median: 22.8%) - Power density of 238.8 W/m² packs 11.1 W/m² more into the same footprint vs \*\*N-type 600-650W\*\* median (227.7 W/m²) - -0.26%/°C temperature coefficient (median: -0.29%/°C) - retains ~1% more power at high temperatures - At 33.5 kg, weight matches the \*\*N-type 600-650W\*\* median - 70% bifaciality enables rear-side power generation, boosting yield by 4-10% on reflective surfaces ## Questions ### What is the back contact technology in the Longi Hi-MO X10 Guardian and why does it matter? In the Hi-MO X10 Guardian, all electrical contacts are moved to the rear side of the cell, leaving the entire front surface free of metal busbars. This maximizes light absorption and supports module efficiency up to 24.8%. Combined with N-type cell technology and a zero-busbar (0BB) structure, the back contact architecture delivers significantly better energy yield than conventional TOPCon or PERC modules of the same size. ### What does the anti-dust frame design in the Longi Hi-MO X10 Guardian actually do, and will it reduce cleaning frequency? The anti-dust frame modifies the edge profile of the glass to reduce dust accumulation along the module perimeter. LONGi states it lowers yield losses from soiling and extends intervals between required cleaning cycles. This is a practical advantage for utility-scale PV farms near roads or industrial facilities and for installations in arid climates with long dry seasons where soiling losses are a major LCOE driver. ### How does the Hi-MO X10 Guardian (LR7-72HVDF 640~665M) handle partial shading from chimneys or rooftop obstructions? The series uses a built-in shading optimizer within its back contact cell architecture. According to LONGi's data, this reduces power loss from partial shading by up to 70% compared to TOPCon modules. The bifacial design further recovers reflected light from the ground or rooftop surface. This makes the series well-suited for C&I roofs with architectural obstacles and for utility projects where inter-row shading occurs during low-sun hours. ### What warranty does the Longi Solar Hi-MO X10 Guardian carry, and what power output can be expected after 30 years? LONGi provides a 15-year product warranty covering materials and workmanship, and a 30-year linear power warranty. First-year degradation is capped at 1%, followed by a 0.35% annual linear degradation rate, guaranteeing at least 88.85% of rated power output at the end of year 30. As a Tier 1 manufacturer, LONGi's warranty is generally considered low-risk for long-term project financing. ### How well do the Longi Hi-MO X10 Guardian panels perform in high summer temperatures? The power temperature coefficient is -0.26%/°C, among the best in the 640–665 Wp module class. For every 10°C rise in module temperature above 25°C, output drops only ~2.6%, compared to ~3.5% for standard PERC modules. The back contact architecture also reduces the risk of localized overheating (hotspots), improving both safety and long-term reliability throughout the module's operating lifetime. ### What types of installations are the Longi Hi-MO X10 Guardian 665W modules best suited for, and do they work on large industrial rooftops? The series is designed primarily for utility-scale PV farms and large C&I rooftop installations. Module dimensions are 2382×1134×30 mm with a weight of approximately 33.5 kg, so structural load capacity and racking design must be verified beforehand. The 665 Wp peak power and high module efficiency reduce the number of modules needed per MW, lowering BoS costs. Built-in resistance to soiling, shading, and hotspots reduces O&M costs over the full 30-year power warranty period. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/lr-7-72-hvdf-640-665-m-30-30-and-15-frame-guardian-anti-dust-7c6b152cf7b2.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Lighter, +1.3 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +35 W, lighter, +1.3 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +30 W, lighter, +1.1 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Lighter, +1.1 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +50 W, heavier, +1.0 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +25 W, lighter, +0.9 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +25 W, lighter, +0.9 pp | | [Longi Solar LR8-66HGD-595M](https://comparepv.com/panel/longi-lr8-66hgd-595m) | 595 W | -50 W, hotter, -1.9 pp | | [Longi Solar LR7-72HGD-600M](https://comparepv.com/panel/longi-lr7-72hgd-600m) | 600 W | -45 W, hotter, -1.7 pp | | [Longi Solar 600M](https://comparepv.com/panel/longi-600m) | 600 W | -45 W, -1.5 pp, -5 yr warranty | | [Longi Solar LR7-72HTH-605M](https://comparepv.com/panel/longi-lr7-72hth-605m) | 605 W | Lighter, -1.5 pp, -5 yr warranty | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +55 W, heavier, +1.1 pp | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | +25 W, lighter, +0.9 pp | --- Source: https://comparepv.com/panel/longi-lr7-72hvdf-645m Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.