Panasonic EverVolt H 410W vs Silfab Elite SIL-420
The Panasonic EverVolt H 410W wins this comparison by a narrow margin. It leads in efficiency (21.6% vs 21.5%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Panasonic EverVolt H 410W is the stronger choice.
Key Differences
- • Panasonic EverVolt H 410W is rated at 410W while Silfab Elite SIL-420 is rated at 420W, a 10W difference.
- • Panasonic EverVolt H 410W achieves 21.6% efficiency vs 21.5% for the other, a 0.1 percentage point gap.
- • Both carry matching 25-year product warranties.
- • Panasonic EverVolt H 410W has a superior temperature coefficient of -0.26%/°C vs -0.29%/°C, retaining more power in hot climates.
- • Panasonic EverVolt H 410W uses HJT (Heterojunction) cells while Silfab Elite SIL-420 uses TOPCon N-type cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Panasonic EverVolt H 410W achieves 21.6% module efficiency compared to Silfab Elite SIL-420's 21.5%, meaning Panasonic EverVolt H 410W converts 0.1 percentage points more sunlight into electricity per square meter. In practical terms, the Panasonic EverVolt H 410W produces 210.0 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 410W for the Panasonic EverVolt H 410W, a 10W difference per module. To build an 8 kW residential system, you would need 20 Panasonic EverVolt H 410W 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 EverVolt H 410W 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 EverVolt H 410W 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 EverVolt H 410W 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 EverVolt H 410W; 1% first year then 0.4%/year for Silfab Elite SIL-420), after 25 years the Panasonic EverVolt H 410W 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 EverVolt H 410W measures 1722×1134×30mm and weighs 21.5 kg, while the Silfab Elite SIL-420 measures 1722×1134×30mm at 21.5 kg. 1.95 m² of panel area for the Panasonic EverVolt H 410W 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 EverVolt H 410W | Silfab Elite SIL-420 |
|---|---|---|
| Power | 410W | 420W |
| Efficiency | 21.6% | 21.5% |
| Power Density | 19.5 W/sq ft | 20.0 W/sq ft |
| Cell Type | HJT (Heterojunction) | TOPCon N-type |
| Bifacial | Yes | No |
| Weight | 21.5 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: Panasonic EverVolt H 410WThe Panasonic EverVolt H 410W achieves 21.6% efficiency versus 21.5% — a 0.1 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.3 kW more total system capacity, or 2 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: Panasonic EverVolt H 410WThe Panasonic EverVolt H 410W 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 EverVolt H 410WPanasonic EverVolt H 410W 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 EverVolt H 410W and Silfab Elite SIL-420 respectively.
4. Power Output
Winner: Silfab Elite SIL-420The Silfab Elite SIL-420 delivers 420W versus 410W per panel — 10W 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 EverVolt H 410WThe Panasonic EverVolt H 410W 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 EverVolt H 410W
DISCONTINUED: Panasonic exited solar manufacturing in 2023. The EverVolt H delivered 410W HJT performance in a compact residential format backed by Panasonic's 25-year complete warranty.
Pros
- + 25-year product warranty
- + HJT technology
- + Excellent temperature performance
- + Compact design
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 EverVolt H 410W If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ 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...
- ✓ 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 EverVolt H 410W and Silfab Elite SIL-420 are excellent solar panel options, and the margin between them is narrow. The Panasonic EverVolt H 410W wins 4 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 EverVolt H 410W or Silfab Elite SIL-420?
The Panasonic EverVolt H 410W wins this comparison by a narrow margin. It leads in efficiency (21.6% vs 21.5%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Panasonic EverVolt H 410W is the stronger choice.
Which panel is more efficient, Panasonic EverVolt H 410W or Silfab Elite SIL-420?
The Panasonic EverVolt H 410W at 21.6% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.1 percentage points translates to approximately 10W per panel under standard test conditions.
Which has a better warranty, Panasonic EverVolt H 410W or Silfab Elite SIL-420?
The Panasonic EverVolt H 410W 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 EverVolt H 410W has a temperature coefficient of -0.26%/°C and the Silfab Elite SIL-420 is -0.29%/°C. Panasonic EverVolt H 410W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many Panasonic EverVolt H 410W vs Silfab Elite SIL-420 panels do I need for an 8 kW system?
For an 8 kW system: you need 20 Panasonic EverVolt H 410W panels (410W 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.
Related Resources
Last updated: February 2026