LONGi Hi-MO 6 580W vs LONGi Hi-MO X6 445W
The LONGi Hi-MO 6 580W wins this comparison by a clear margin. It leads in efficiency (22.3% vs 22%) and matches or exceeds on warranty (12 vs 12 years). For most residential installations, the LONGi Hi-MO 6 580W is the stronger choice.
Key Differences
- • LONGi Hi-MO 6 580W is rated at 580W while LONGi Hi-MO X6 445W is rated at 445W, a 135W difference.
- • LONGi Hi-MO 6 580W achieves 22.3% efficiency vs 22% for the other, a 0.3 percentage point gap.
- • Both carry matching 12-year product warranties.
- • LONGi Hi-MO 6 580W uses HPBC (Hybrid Passivated Back Contact) cells while LONGi Hi-MO X6 445W uses TOPCon N-type cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The LONGi Hi-MO 6 580W achieves 22.3% module efficiency compared to LONGi Hi-MO X6 445W's 22%, meaning LONGi Hi-MO 6 580W converts 0.3 percentage points more sunlight into electricity per square meter. In practical terms, the LONGi Hi-MO 6 580W produces 224.5 watts per square meter of panel area while the LONGi Hi-MO X6 445W produces 227.9 W/m². For rooftop installations where space is limited, this efficiency gap determines how many kilowatts you can fit on your available roof area. Over a 25-year system life, even a small efficiency advantage compounds into meaningful additional energy production.
Power Output
The LONGi Hi-MO 6 580W delivers 580W per panel versus 445W for the LONGi Hi-MO X6 445W, a 135W difference per module. To build an 8 kW residential system, you would need 14 LONGi Hi-MO 6 580W panels or 18 LONGi Hi-MO X6 445W panels. Choosing the higher-wattage option saves 4 panels, reducing total racking hardware, wiring, and installation labor costs. Higher wattage per panel is particularly valuable for commercial-scale installations where panel count directly impacts balance-of-system costs.
Temperature Coefficient
Both panels share an identical temperature coefficient of -0.29%/°C, meaning they lose power at the same rate as cell temperature rises above the 25°C standard test baseline. At 65°C cell temperature, both retain 94.2% of rated power. Neither panel has a thermal performance advantage, which makes this specification a non-factor in the comparison.
Warranty Coverage
The LONGi Hi-MO 6 580W is backed by a 12-year product warranty and 25-year performance guarantee, while the LONGi Hi-MO X6 445W offers 12-year product and 25-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (1.5% first year then 0.5%/year for LONGi Hi-MO 6 580W; 1% first year then 0.4%/year for LONGi Hi-MO X6 445W), after 25 years the LONGi Hi-MO 6 580W should retain approximately 86.5% of original output versus 89.4% for the LONGi Hi-MO X6 445W. This 2.9 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The LONGi Hi-MO 6 580W measures 2278×1134×35mm and weighs 28.4 kg, while the LONGi Hi-MO X6 445W measures 1722×1134×30mm at 21.5 kg. 2.58 m² of panel area for the LONGi Hi-MO 6 580W versus 1.95 m² for the LONGi Hi-MO X6 445W. The LONGi Hi-MO X6 445W is 6.9 kg lighter per panel, which reduces structural load requirements on the roof and makes handling easier during installation. For a 20-panel system, that is a total weight difference of 138 kg. The more compact LONGi Hi-MO X6 445W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | LONGi Hi-MO 6 580W | LONGi Hi-MO X6 445W |
|---|---|---|
| Power | 580W | 445W |
| Efficiency | 22.3% | 22% |
| Power Density | 20.9 W/sq ft | 21.2 W/sq ft |
| Cell Type | HPBC (Hybrid Passivated Back Contact) | TOPCon N-type |
| Bifacial | No | Yes |
| Weight | 28.4 kg | 21.5 kg |
| Temp Coefficient | -0.29%/°C | -0.29%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 12 years | 12 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 1.5% | 1% |
| Annual Degradation | 0.5% | 0.4% |
| Country | China | China |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: LONGi Hi-MO 6 580WThe LONGi Hi-MO 6 580W achieves 22.3% efficiency versus 22% — a 0.3 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 4.0 kW more total system capacity, or 19 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: TieBoth panels share a temperature coefficient of -0.29%/°C — identical heat tolerance.
3. Durability & Warranty
Winner: LONGi Hi-MO X6 445WLONGi Hi-MO X6 445W degrades more slowly at 0.4% per year versus 0.5%. After 25 years, expect 86.5% vs 89.4% of original output for LONGi Hi-MO 6 580W and LONGi Hi-MO X6 445W respectively.
4. Power Output
Winner: LONGi Hi-MO 6 580WThe LONGi Hi-MO 6 580W delivers 580W versus 445W per panel — 135W more. For an 8 kW system, you need 14 panels with the higher-wattage option versus 18 panels, saving 4 panels and the associated racking and labor costs.
5. Cell Technology
Winner: LONGi Hi-MO 6 580WThe LONGi Hi-MO 6 580W uses HPBC (Hybrid Passivated Back Contact): HPBC (Hybrid Passivated Back Contact) is a proprietary LONGi architecture combining back-contact design with advanced passivation for both high efficiency and aesthetic uniformity. The LONGi Hi-MO X6 445W uses TOPCon N-type: TOPCon (Tunnel Oxide Passivated Contact) adds a thin tunnel oxide layer to reduce recombination losses, achieving higher efficiency than PERC while being manufacturable on existing production lines. HPBC (Hybrid Passivated Back Contact) represents a newer generation technology with a longer performance runway as manufacturing matures.
LONGi Hi-MO 6 580W
LONGi Hi-MO 6 is a high-performance PERC mono half-cut panel delivering 580W with 22.3% efficiency, ideal for residential and commercial rooftops.
Pros
- + High 22.3% efficiency
- + Proven PERC technology
- + Strong bifacial gain potential
- + Competitive pricing
Cons
- - Large physical size
- - Requires compatible racking
- - Limited US availability
LONGi Hi-MO X6 445W
The Hi-MO X6 is LONGi's TOPCon N-type line offering 445W in a compact format, well-suited for space-constrained residential rooftops.
Pros
- + Compact size for residential roofs
- + Good N-type TOPCon efficiency
- + Advanced technology
- + Budget-friendly
Cons
- - Lower wattage than larger models
- - Mid-range efficiency for N-type
- - Less suited for very large roofs
Choose LONGi Hi-MO 6 580W If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ You want fewer panels to reach your target system size, reducing racking and labor costs
- ✓ Homeowners wanting high-output PERC performance at a competitive price.
Choose LONGi Hi-MO X6 445W If...
- ✓ You want maximum output retention over the system's 25-30 year lifespan
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Homeowners wanting N-type TOPCon technology in a compact residential format.
Our Recommendation
We recommend the LONGi Hi-MO 6 580W for most buyers in this comparison. It wins 3 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The LONGi Hi-MO X6 445W remains a good product, but the LONGi Hi-MO 6 580W delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, LONGi Hi-MO 6 580W or LONGi Hi-MO X6 445W?
The LONGi Hi-MO 6 580W wins this comparison by a clear margin. It leads in efficiency (22.3% vs 22%) and matches or exceeds on warranty (12 vs 12 years). For most residential installations, the LONGi Hi-MO 6 580W is the stronger choice.
Which panel is more efficient, LONGi Hi-MO 6 580W or LONGi Hi-MO X6 445W?
The LONGi Hi-MO 6 580W at 22.3% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.3 percentage points translates to approximately 135W per panel under standard test conditions.
Which has a better warranty, LONGi Hi-MO 6 580W or LONGi Hi-MO X6 445W?
The LONGi Hi-MO 6 580W comes with a 12-year product warranty and 25-year performance guarantee. The LONGi Hi-MO X6 445W offers 12-year product and 25-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The LONGi Hi-MO 6 580W has a temperature coefficient of -0.29%/°C and the LONGi Hi-MO X6 445W is -0.29%/°C. Both handle heat equally. A lower (less negative) temperature coefficient is better.
How many LONGi Hi-MO 6 580W vs LONGi Hi-MO X6 445W panels do I need for an 8 kW system?
For an 8 kW system: you need 14 LONGi Hi-MO 6 580W panels (580W each) or 18 LONGi Hi-MO X6 445W panels (445W each). The LONGi Hi-MO 6 580W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026