LONGi Hi-MO 6 580W vs Yingli Solar YLM 144 Cell 550W
The LONGi Hi-MO 6 580W wins this comparison by a clear margin. It leads in efficiency (22.3% vs 21.3%) 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 Yingli Solar YLM 144 Cell 550W is rated at 550W, a 30W difference.
- • LONGi Hi-MO 6 580W achieves 22.3% efficiency vs 21.3% for the other, a 1.0 percentage point gap.
- • Both carry matching 12-year product warranties.
- • LONGi Hi-MO 6 580W has a superior temperature coefficient of -0.29%/°C vs -0.34%/°C, retaining more power in hot climates.
- • LONGi Hi-MO 6 580W uses HPBC (Hybrid Passivated Back Contact) cells while Yingli Solar YLM 144 Cell 550W uses PERC Mono cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The LONGi Hi-MO 6 580W achieves 22.3% module efficiency compared to Yingli Solar YLM 144 Cell 550W's 21.3%, meaning LONGi Hi-MO 6 580W converts 1.0 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 Yingli Solar YLM 144 Cell 550W produces 212.9 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 550W for the Yingli Solar YLM 144 Cell 550W, a 30W difference per module. To build an 8 kW residential system, you would need 14 LONGi Hi-MO 6 580W panels or 15 Yingli Solar YLM 144 Cell 550W panels. Choosing the higher-wattage option saves 1 panel, 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
The LONGi Hi-MO 6 580W has a temperature coefficient of -0.29%/°C versus -0.34%/°C for the Yingli Solar YLM 144 Cell 550W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the LONGi Hi-MO 6 580W retains 94.2% of its rated power while the other retains 93.2%. This difference is particularly significant in hot climates such as the American Southwest, the Middle East, and Southeast Asia, where panels routinely operate 30-40°C above STC for several hours each day. Over the system lifetime, the cumulative energy advantage from a better temperature coefficient can amount to 2-4% of total production.
Warranty Coverage
The LONGi Hi-MO 6 580W is backed by a 12-year product warranty and 25-year performance guarantee, while the Yingli Solar YLM 144 Cell 550W 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; 1.5% first year then 0.5%/year for Yingli Solar YLM 144 Cell 550W), after 25 years the LONGi Hi-MO 6 580W should retain approximately 86.5% of original output versus 86.5% for the Yingli Solar YLM 144 Cell 550W. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The LONGi Hi-MO 6 580W measures 2278×1134×35mm and weighs 28.4 kg, while the Yingli Solar YLM 144 Cell 550W measures 2278×1134×35mm at 28.5 kg. 2.58 m² of panel area for the LONGi Hi-MO 6 580W versus 2.58 m² for the Yingli Solar YLM 144 Cell 550W. Their weights are closely matched, so neither panel imposes a significantly different structural load on the mounting system. Similar footprints mean both panels fit comparably on standard residential rooftop configurations.
Specification Comparison
| Specification | LONGi Hi-MO 6 580W | Yingli Solar YLM 144 Cell 550W |
|---|---|---|
| Power | 580W | 550W |
| Efficiency | 22.3% | 21.3% |
| Power Density | 20.9 W/sq ft | 19.8 W/sq ft |
| Cell Type | HPBC (Hybrid Passivated Back Contact) | PERC Mono |
| Bifacial | No | No |
| Weight | 28.4 kg | 28.5 kg |
| Temp Coefficient | -0.29%/°C | -0.34%/°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% | 1.5% |
| Annual Degradation | 0.5% | 0.5% |
| 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 21.3% — a 1.0 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.9 kW more total system capacity, or 5 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: LONGi Hi-MO 6 580WThe LONGi Hi-MO 6 580W has a better temperature coefficient of -0.29%/°C versus -0.34%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.2% of rated power versus 93.2%. This is a meaningful difference in hot states like Arizona, Texas, and Florida.
3. Durability & Warranty
Winner: TieBoth panels offer identical 12-year product warranties and 0.5% annual degradation. Neither has a durability advantage.
4. Power Output
Winner: LONGi Hi-MO 6 580WThe LONGi Hi-MO 6 580W delivers 580W versus 550W per panel — 30W more. For an 8 kW system, you need 14 panels with the higher-wattage option versus 15 panels, saving 1 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 Yingli Solar YLM 144 Cell 550W uses PERC Mono: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. 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
Yingli Solar YLM 144 Cell 550W
Yingli Solar YLM 144 Cell is a high-output PERC module for commercial installations at a competitive price point.
Pros
- + High 550W output
- + Competitive commercial pricing
- + Proven track record
- + Large format
Cons
- - Older PERC technology
- - Heavy panel
- - Brand perception concerns
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
- ✓ You live in a hot climate (Arizona, Texas, Florida) where heat performance matters
- ✓ Homeowners wanting high-output PERC performance at a competitive price.
Choose Yingli Solar YLM 144 Cell 550W If...
- ✓ Commercial projects seeking affordable high-output PERC modules.
Our Recommendation
We recommend the LONGi Hi-MO 6 580W for most buyers in this comparison. It wins 4 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The Yingli Solar YLM 144 Cell 550W 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 Yingli Solar YLM 144 Cell 550W?
The LONGi Hi-MO 6 580W wins this comparison by a clear margin. It leads in efficiency (22.3% vs 21.3%) 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 Yingli Solar YLM 144 Cell 550W?
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 1.0 percentage points translates to approximately 30W per panel under standard test conditions.
Which has a better warranty, LONGi Hi-MO 6 580W or Yingli Solar YLM 144 Cell 550W?
The LONGi Hi-MO 6 580W comes with a 12-year product warranty and 25-year performance guarantee. The Yingli Solar YLM 144 Cell 550W 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 Yingli Solar YLM 144 Cell 550W is -0.34%/°C. LONGi Hi-MO 6 580W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many LONGi Hi-MO 6 580W vs Yingli Solar YLM 144 Cell 550W 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 15 Yingli Solar YLM 144 Cell 550W panels (550W 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