Strong in heat, no clear weak spot
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.
Ranking
Signals from the data
Commercial, utility-scale, hot-climate and shaded-installations.
Top 4% of the N-type 600-650 W segment, against a median of -0.290. Ranked 511th in the whole database.
Top 6% of the N-type 600-650 W segment, against a median of 22.77%. Ranked 517th in the whole database.
Top 7% of the N-type 600-650 W segment, against a median of 227.7. Ranked 521st in the whole database.
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%).
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.
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.
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 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.
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.
- Efficiency of 23.7% is 0.9pp above the N-type 600-650W median (22.8%)
- Power density of 236.9 W/m² packs 9.2 W/m² more into the same footprint vs N-type 600-650W median (227.7 W/m²)
- Temperature coefficient of -0.26%/°C vs median -0.29%/°C means ~1% less power loss at 65°C
- Weight of 33.5 kg is typical for N-type 600-650W panels
- Bifacial design (70% factor) captures reflected light - adds 4-10% yield on ground-mount or white roof
Specifications
Datasheet charts
Measured curves published by Longi Solar in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 640 Wp appear here. The rest cover the whole series.
Simulations
Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.
Model: bifaciality × albedo × 0.6 view factor. A first-order estimate, not a yield simulation.
Found 1119 panels of the same or similar size to this one, within ±10 mm. See them here Found 1125 panels of the same or similar size to this one, within ±25 mm. See them here Found 1236 panels of the same or similar size to this one, within ±50 mm. See them here Found 1917 panels of the same or similar size to this one, within ±100 mm. See them here