Panasonic EVPV400H vs Silfab Elite SIL-420
The Panasonic EVPV400H wins this comparison by a narrow margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Panasonic EVPV400H is the stronger choice.
Key Differences
- • Panasonic EVPV400H is rated at 400W while Silfab Elite SIL-420 is rated at 420W, a 20W difference.
- • Silfab Elite SIL-420 achieves 21.5% efficiency vs 21.2% for the other, a 0.3 percentage point gap.
- • Both carry matching 25-year product warranties.
- • Panasonic EVPV400H has a superior temperature coefficient of -0.26%/°C vs -0.29%/°C, retaining more power in hot climates.
- • Panasonic EVPV400H uses HJT (Heterojunction) cells while Silfab Elite SIL-420 uses TOPCon N-type cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Silfab Elite SIL-420 achieves 21.5% module efficiency compared to Panasonic EVPV400H's 21.2%, meaning Silfab Elite SIL-420 converts 0.3 percentage points more sunlight into electricity per square meter. In practical terms, the Panasonic EVPV400H produces 204.8 watts per square meter of panel area while the Silfab Elite SIL-420 produces 215.1 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 Silfab Elite SIL-420 delivers 420W per panel versus 400W for the Panasonic EVPV400H, a 20W difference per module. To build an 8 kW residential system, you would need 20 Panasonic EVPV400H panels or 20 Silfab Elite SIL-420 panels. Despite the per-panel wattage difference, both require the same number of panels for this system size due to rounding. 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 Silfab Elite SIL-420. 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 Panasonic EVPV400H is backed by a 25-year product warranty and 25-year performance guarantee, while the Silfab Elite SIL-420 offers 25-year product and 30-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (0.5% first year then 0.35%/year for Panasonic EVPV400H; 1% first year then 0.4%/year for Silfab Elite SIL-420), after 25 years the Panasonic EVPV400H should retain approximately 91.1% of original output versus 89.4% for the Silfab Elite SIL-420. This 1.7 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The Panasonic EVPV400H measures 1722×1134×30mm and weighs 21 kg, while the Silfab Elite SIL-420 measures 1722×1134×30mm at 21.5 kg. 1.95 m² of panel area for the Panasonic EVPV400H versus 1.95 m² for the Silfab Elite SIL-420. 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 | Panasonic EVPV400H | Silfab Elite SIL-420 |
|---|---|---|
| Power | 400W | 420W |
| Efficiency | 21.2% | 21.5% |
| Power Density | 19.0 W/sq ft | 20.0 W/sq ft |
| Cell Type | HJT (Heterojunction) | TOPCon N-type |
| Bifacial | Yes | No |
| Weight | 21 kg | 21.5 kg |
| Temp Coefficient | -0.26%/°C | -0.29%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 25 years | 25 years |
| Performance Warranty | 25 years | 30 years |
| Degradation (Year 1) | 0.5% | 1% |
| Annual Degradation | 0.35% | 0.4% |
| Country | Japan | United States |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Silfab Elite SIL-420The Silfab Elite SIL-420 achieves 21.5% efficiency versus 21.2% — a 0.3 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.6 kW more total system capacity, or 3 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 degrades more slowly at 0.35% per year versus 0.4%. After 25 years, expect 91.1% vs 89.4% of original output for Panasonic EVPV400H and Silfab Elite SIL-420 respectively.
4. Power Output
Winner: Silfab Elite SIL-420The Silfab Elite SIL-420 delivers 420W versus 400W per panel — 20W more. For an 8 kW system, you need 20 panels with the higher-wattage option versus 20 panels, saving 0 panels and the associated racking and labor costs.
5. Cell Technology
Winner: Panasonic EVPV400HThe 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. The Silfab Elite SIL-420 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. HJT (Heterojunction) represents a newer generation technology with a longer performance runway as manufacturing matures.
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
Silfab Elite SIL-420
The Silfab Elite SIL-420 is a premium US-made N-type panel delivering 420W with advanced TOPCon cells and domestic manufacturing.
Pros
- + US manufactured premium panel
- + N-type technology
- + 25-year warranty
- + ARRA compliant
Cons
- - Premium pricing
- - Moderate wattage
- - Limited distribution
Choose Panasonic EVPV400H If...
- ✓ 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.
Choose Silfab Elite SIL-420 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
- ✓ Premium residential installations requiring US-made N-type panels.
Our Recommendation
Both the Panasonic EVPV400H and Silfab Elite SIL-420 are excellent solar panel options, and the margin between them is narrow. The Panasonic EVPV400H wins 3 of 5 comparison dimensions by a slim margin. Your decision may come down to local pricing, installer availability, and which specific performance metrics matter most for your project. Either product is a solid investment.
Frequently Asked Questions
Which is better, Panasonic EVPV400H or Silfab Elite SIL-420?
The Panasonic EVPV400H wins this comparison by a narrow 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, Panasonic EVPV400H or Silfab Elite SIL-420?
The Silfab Elite SIL-420 at 21.5% 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 20W per panel under standard test conditions.
Which has a better warranty, Panasonic EVPV400H or Silfab Elite SIL-420?
The Panasonic EVPV400H comes with a 25-year product warranty and 25-year performance guarantee. The Silfab Elite SIL-420 offers 25-year product and 30-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The Panasonic EVPV400H has a temperature coefficient of -0.26%/°C and the Silfab Elite SIL-420 is -0.29%/°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 Panasonic EVPV400H vs Silfab Elite SIL-420 panels do I need for an 8 kW system?
For an 8 kW system: you need 20 Panasonic EVPV400H panels (400W each) or 20 Silfab Elite SIL-420 panels (420W each). The Silfab Elite SIL-420 requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026