LONGi Hi-MO X6 445W vs Panasonic EVPV400H
The Panasonic EVPV400H wins this comparison by a decisive margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Panasonic EVPV400H is the stronger choice.
Key Differences
- • LONGi Hi-MO X6 445W is rated at 445W while Panasonic EVPV400H is rated at 400W, a 45W difference.
- • LONGi Hi-MO X6 445W achieves 22% efficiency vs 21.2% for the other, a 0.8 percentage point gap.
- • Panasonic EVPV400H comes with a 25-year product warranty vs 12 years for the other.
- • Panasonic EVPV400H has a superior temperature coefficient of -0.26%/°C vs -0.29%/°C, retaining more power in hot climates.
- • LONGi Hi-MO X6 445W uses TOPCon N-type cells while Panasonic EVPV400H uses HJT (Heterojunction) cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The LONGi Hi-MO X6 445W achieves 22% module efficiency compared to Panasonic EVPV400H's 21.2%, meaning LONGi Hi-MO X6 445W converts 0.8 percentage points more sunlight into electricity per square meter. In practical terms, the LONGi Hi-MO X6 445W produces 227.9 watts per square meter of panel area while the Panasonic EVPV400H produces 204.8 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 X6 445W delivers 445W per panel versus 400W for the Panasonic EVPV400H, a 45W difference per module. To build an 8 kW residential system, you would need 18 LONGi Hi-MO X6 445W panels or 20 Panasonic EVPV400H panels. Choosing the higher-wattage option saves 2 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
The Panasonic EVPV400H has a temperature coefficient of -0.26%/°C versus -0.29%/°C for the LONGi Hi-MO X6 445W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Panasonic EVPV400H retains 94.8% of its rated power while the other retains 94.2%. While the numerical gap is modest, it still accumulates over decades of summer production, especially in southern latitudes with prolonged peak heat hours.
Warranty Coverage
The LONGi Hi-MO X6 445W is backed by a 12-year product warranty and 25-year performance guarantee, while the Panasonic EVPV400H offers 25-year product and 25-year performance coverage. The Panasonic EVPV400H provides 13 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (1% first year then 0.4%/year for LONGi Hi-MO X6 445W; 0.5% first year then 0.35%/year for Panasonic EVPV400H), after 25 years the LONGi Hi-MO X6 445W should retain approximately 89.4% of original output versus 91.1% for the Panasonic EVPV400H. This 1.7 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The LONGi Hi-MO X6 445W measures 1722×1134×30mm and weighs 21.5 kg, while the Panasonic EVPV400H measures 1722×1134×30mm at 21 kg. 1.95 m² of panel area for the LONGi Hi-MO X6 445W versus 1.95 m² for the Panasonic EVPV400H. 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 X6 445W | Panasonic EVPV400H |
|---|---|---|
| Power | 445W | 400W |
| Efficiency | 22% | 21.2% |
| Power Density | 21.2 W/sq ft | 19.0 W/sq ft |
| Cell Type | TOPCon N-type | HJT (Heterojunction) |
| Bifacial | Yes | Yes |
| Weight | 21.5 kg | 21 kg |
| Temp Coefficient | -0.29%/°C | -0.26%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 12 years | 25 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 1% | 0.5% |
| Annual Degradation | 0.4% | 0.35% |
| Country | China | Japan |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: LONGi Hi-MO X6 445WThe LONGi Hi-MO X6 445W achieves 22% efficiency versus 21.2% — a 0.8 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 1.4 kW more total system capacity, or 7 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: Panasonic EVPV400HThe Panasonic EVPV400H has a better temperature coefficient of -0.26%/°C versus -0.29%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.8% of rated power versus 94.2%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: Panasonic EVPV400HPanasonic EVPV400H leads with a 25-year product warranty versus 12 years. Panasonic EVPV400H degrades more slowly at 0.35% per year versus 0.4%. After 25 years, expect 89.4% vs 91.1% of original output for LONGi Hi-MO X6 445W and Panasonic EVPV400H respectively.
4. Power Output
Winner: LONGi Hi-MO X6 445WThe LONGi Hi-MO X6 445W delivers 445W versus 400W per panel — 45W more. For an 8 kW system, you need 18 panels with the higher-wattage option versus 20 panels, saving 2 panels and the associated racking and labor costs.
5. Cell Technology
Winner: Panasonic EVPV400HThe 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. The Panasonic EVPV400H uses HJT (Heterojunction): HJT (Heterojunction) combines crystalline silicon with amorphous silicon layers, delivering the best temperature coefficient and bifacial gains, but at higher manufacturing cost. HJT (Heterojunction) represents a newer generation technology with a longer performance runway as manufacturing matures.
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
Panasonic EVPV400H
DISCONTINUED: Panasonic exited solar manufacturing in 2023. The EVPV400H was Panasonic's standard HJT residential panel, delivering 400W with the brand's signature quality and longevity.
Pros
- + Panasonic reliability
- + HJT advantages
- + Solid 25-year warranty
- + Good all-round performer
Cons
- - DISCONTINUED - no longer manufactured
- - No new units available
- - No ongoing product support
Choose LONGi Hi-MO X6 445W 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 prefer newer cell technology with a longer performance improvement runway
- ✓ Homeowners wanting N-type TOPCon technology in a compact residential format.
Choose Panasonic EVPV400H If...
- ✓ Long-term warranty protection is a top priority and you plan to stay in your home for 25+ years
- ✓ You live in a hot climate (Arizona, Texas, Florida) where heat performance matters
- ✓ You want maximum output retention over the system's 25-30 year lifespan
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ No longer available for new installations.
Our Recommendation
The Panasonic EVPV400H is the decisive winner in this solar panel comparison, outperforming the LONGi Hi-MO X6 445W in 3 of 5 dimensions. Unless you have a specific requirement that the LONGi Hi-MO X6 445W uniquely addresses, the Panasonic EVPV400H is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, LONGi Hi-MO X6 445W or Panasonic EVPV400H?
The Panasonic EVPV400H wins this comparison by a decisive margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Panasonic EVPV400H is the stronger choice.
Which panel is more efficient, LONGi Hi-MO X6 445W or Panasonic EVPV400H?
The LONGi Hi-MO X6 445W at 22% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.8 percentage points translates to approximately 45W per panel under standard test conditions.
Which has a better warranty, LONGi Hi-MO X6 445W or Panasonic EVPV400H?
The LONGi Hi-MO X6 445W comes with a 12-year product warranty and 25-year performance guarantee. The Panasonic EVPV400H offers 25-year product and 25-year performance warranties. Panasonic EVPV400H provides 13 additional years of product coverage.
Which panel performs better in hot weather?
The LONGi Hi-MO X6 445W has a temperature coefficient of -0.29%/°C and the Panasonic EVPV400H is -0.26%/°C. Panasonic EVPV400H 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 X6 445W vs Panasonic EVPV400H panels do I need for an 8 kW system?
For an 8 kW system: you need 18 LONGi Hi-MO X6 445W panels (445W each) or 20 Panasonic EVPV400H panels (400W each). The LONGi Hi-MO X6 445W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026