Efficiency leader, no clear weak spot
Longi Solar Hi-MO 9 is a breakthrough series of modules that redefines performance standards through the use of advanced HPBC 2.0 cell technology. This solution eliminates losses resulting from shading the front part of the cell by busbars, which directly translates into record efficiency and modern aesthetics. These panels are the ideal choice for investors seeking maximum energy yield from limited roof area, effectively solving the problem of space shortages in ambitious projects. Thanks to its optimized internal structure, Hi-MO 9 demonstrates exceptional resistance to degradation and stable operation even in low-light conditions, guaranteeing real gains on cloudy days. The innovative design also ensures an excellent temperature coefficient, limiting power drops during summer heat. This series is dedicated to both demanding households and large-scale solar farms, where the lowest levelized cost of energy is key. Compared to the competition, Hi-MO 9 stands out with a unique hybrid structure that combines the highest efficiency with long-term mechanical reliability. It is a safe and future-proof choice for anyone focusing on the highest quality of workmanship and the most modern technological thought in the photovoltaic industry.
Ranking
Signals from the data
Residential, utility-scale and hot-climate.
Top 12% of the Back Contact 650-700 W segment, against a median of 24.40%.
Top 12% of the Back Contact 650-700 W segment, against a median of 244.3.
HPBC 2.0 back-contact cell technology eliminates front-side busbar shading, reaching up to 24.8% efficiency and 670 Wp. That is roughly 3.2 percentage points higher than comparable modules - Hiwatt HW-M12/132H (21.6%) and Techwise Summit Series / Resun RS9H-M (21.57% each) - at the same 670 Wp max power, yielding about 6.4% more installed capacity per equivalent roof area.
First-year degradation is capped at 1%, with no more than 0.35% annual degradation thereafter, retaining about 88.85% of original power output after 30 years. This clearly outperforms typical PERC modules with annual degradation around 0.5-0.6%.
The manufacturer covers the modules with a 30-year linear power warranty, longer than the industry-standard 25 years offered by most tier-1 manufacturers. Combined with the low degradation rate, this delivers a genuinely higher lifetime energy yield.
The power temperature coefficient is -0.26%/°C, better than the typical -0.35% to -0.40%/°C for standard silicon modules. This means smaller power losses during summer heat, especially relevant in warmer climates.
LONGi Solar is a BNEF Tier-1 manufacturer, operating since 2000 and among the world's largest PV module suppliers. This bankability status eases project financing for large-scale installations and boosts confidence in warranty servicing.
The product warranty is 12 years, while some tier-1 competitors (e.g., other N-type TOPCon modules) offer 15-25 years of product warranty alongside the same 30-year power warranty. This gap is worth noting when comparing servicing terms.
Back-contact (HPBC) modules typically carry a 5-10% price premium over comparable TOPCon modules due to the more complex cell manufacturing process without front-side busbars. This can raise project LCOE relative to cheaper TOPCon alternatives of similar power class.
- Efficiency of 24.8% matches the Back Contact 650-700W median
- 248.0 W/m² power density - 3.7 W/m² more than Back Contact 650-700W median (244.3 W/m²), more power per roof area
- Temperature coefficient of -0.26%/°C matches the Back Contact 650-700W median
- 75% bifaciality enables rear-side power generation, boosting yield by 4-11% on reflective surfaces
- In the top 0% for efficiency among all Back Contact panels
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 670 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.
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About the Hi-MO 9 series
These answers cover the whole series. Where a figure differs, the specification above is this module's own.