Panasonic EVPV400H vs CertainTeed Solstice Solar Panel 365W
The Panasonic EVPV400H wins this comparison by a decisive margin. It leads in efficiency (21.2% vs 19.9%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Panasonic EVPV400H is the stronger choice.
Key Differences
- • Panasonic EVPV400H is rated at 400W while CertainTeed Solstice Solar Panel 365W is rated at 365W, a 35W difference.
- • Panasonic EVPV400H achieves 21.2% efficiency vs 19.9% for the other, a 1.3 percentage point gap.
- • Panasonic EVPV400H comes with a 25-year product warranty vs 10 years for the other.
- • Panasonic EVPV400H has a superior temperature coefficient of -0.26%/°C vs -0.36%/°C, retaining more power in hot climates.
- • Panasonic EVPV400H uses HJT (Heterojunction) cells while CertainTeed Solstice Solar Panel 365W uses Monocrystalline PERC cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Panasonic EVPV400H achieves 21.2% module efficiency compared to CertainTeed Solstice Solar Panel 365W's 19.9%, meaning Panasonic EVPV400H converts 1.3 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 CertainTeed Solstice Solar Panel 365W produces 199.2 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 Panasonic EVPV400H delivers 400W per panel versus 365W for the CertainTeed Solstice Solar Panel 365W, a 35W difference per module. To build an 8 kW residential system, you would need 20 Panasonic EVPV400H panels or 22 CertainTeed Solstice Solar Panel 365W 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 -0.36%/°C for the CertainTeed Solstice Solar Panel 365W. 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 92.8%. 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 Panasonic EVPV400H is backed by a 25-year product warranty and 25-year performance guarantee, while the CertainTeed Solstice Solar Panel 365W offers 10-year product and 25-year performance coverage. The Panasonic EVPV400H provides 15 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (0.5% first year then 0.35%/year for Panasonic EVPV400H; 2% first year then 0.55%/year for CertainTeed Solstice Solar Panel 365W), after 25 years the Panasonic EVPV400H should retain approximately 91.1% of original output versus 84.8% for the CertainTeed Solstice Solar Panel 365W. This 6.3 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 CertainTeed Solstice Solar Panel 365W measures 1755×1044×40mm at 21.6 kg. 1.95 m² of panel area for the Panasonic EVPV400H versus 1.83 m² for the CertainTeed Solstice Solar Panel 365W. Their weights are closely matched, so neither panel imposes a significantly different structural load on the mounting system. The more compact CertainTeed Solstice Solar Panel 365W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | Panasonic EVPV400H | CertainTeed Solstice Solar Panel 365W |
|---|---|---|
| Power | 400W | 365W |
| Efficiency | 21.2% | 19.9% |
| Power Density | 19.0 W/sq ft | 18.5 W/sq ft |
| Cell Type | HJT (Heterojunction) | Monocrystalline PERC |
| Bifacial | Yes | No |
| Weight | 21 kg | 21.6 kg |
| Temp Coefficient | -0.26%/°C | -0.36%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 25 years | 10 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 0.5% | 2% |
| Annual Degradation | 0.35% | 0.55% |
| Country | Japan | United States |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Panasonic EVPV400HThe Panasonic EVPV400H achieves 21.2% efficiency versus 19.9% — a 1.3 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 1.1 kW more total system capacity, or 5 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 -0.36%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.8% of rated power versus 92.8%. This is a meaningful difference in hot states like Arizona, Texas, and Florida.
3. Durability & Warranty
Winner: Panasonic EVPV400HPanasonic EVPV400H leads with a 25-year product warranty versus 10 years. Panasonic EVPV400H degrades more slowly at 0.35% per year versus 0.55%. After 25 years, expect 91.1% vs 84.8% of original output for Panasonic EVPV400H and CertainTeed Solstice Solar Panel 365W respectively.
4. Power Output
Winner: Panasonic EVPV400HThe Panasonic EVPV400H delivers 400W versus 365W per panel — 35W more. For an 8 kW system, you need 20 panels with the higher-wattage option versus 22 panels, saving 2 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 CertainTeed Solstice Solar Panel 365W uses Monocrystalline PERC: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. 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
CertainTeed Solstice Solar Panel 365W
The CertainTeed Solstice Solar Panel 365W is a conventional residential solar panel from CertainTeed (Saint-Gobain), using monocrystalline PERC half-cut cells. Designed to pair with CertainTeed roofing products for a coordinated roof-and-solar installation through certified roofing contractors.
Pros
- + Made in the USA by Saint-Gobain subsidiary
- + 10-year product warranty — strong for US-manufactured panel
- + Designed for seamless pairing with CertainTeed roofing
- + Half-cut PERC cells for partial shade resilience
- + Available through established roofing contractor network
Cons
- - 19.9% efficiency below current N-Type leaders
- - 365W output lower than modern 400W+ panels
- - Heavier at 21.6 kg than comparable wattage panels
- - Higher cost per watt than budget alternatives
- - Limited distribution outside CertainTeed roofing dealers
Choose Panasonic EVPV400H 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
- ✓ 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
Choose CertainTeed Solstice Solar Panel 365W If...
- ✓ Homeowners doing a combined roof replacement and solar installation through CertainTeed-certified contractors.
Our Recommendation
The Panasonic EVPV400H is the decisive winner in this solar panel comparison, outperforming the CertainTeed Solstice Solar Panel 365W in 5 of 5 dimensions. Unless you have a specific requirement that the CertainTeed Solstice Solar Panel 365W uniquely addresses, the Panasonic EVPV400H is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, Panasonic EVPV400H or CertainTeed Solstice Solar Panel 365W?
The Panasonic EVPV400H wins this comparison by a decisive margin. It leads in efficiency (21.2% vs 19.9%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Panasonic EVPV400H is the stronger choice.
Which panel is more efficient, Panasonic EVPV400H or CertainTeed Solstice Solar Panel 365W?
The Panasonic EVPV400H at 21.2% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 1.3 percentage points translates to approximately 35W per panel under standard test conditions.
Which has a better warranty, Panasonic EVPV400H or CertainTeed Solstice Solar Panel 365W?
The Panasonic EVPV400H comes with a 25-year product warranty and 25-year performance guarantee. The CertainTeed Solstice Solar Panel 365W offers 10-year product and 25-year performance warranties. Panasonic EVPV400H provides 15 additional years of product coverage.
Which panel performs better in hot weather?
The Panasonic EVPV400H has a temperature coefficient of -0.26%/°C and the CertainTeed Solstice Solar Panel 365W is -0.36%/°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 CertainTeed Solstice Solar Panel 365W panels do I need for an 8 kW system?
For an 8 kW system: you need 20 Panasonic EVPV400H panels (400W each) or 22 CertainTeed Solstice Solar Panel 365W panels (365W each). The Panasonic EVPV400H requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026