First Solar Series 6 Plus 465W vs Seraphim S4 Series 430W
The Seraphim S4 Series 430W wins this comparison by a narrow margin. It leads in efficiency (21.2% vs 19.2%) and matches or exceeds on warranty (12 vs 10 years). For most residential installations, the Seraphim S4 Series 430W is the stronger choice.
Key Differences
- • First Solar Series 6 Plus 465W is rated at 465W while Seraphim S4 Series 430W is rated at 430W, a 35W difference.
- • Seraphim S4 Series 430W achieves 21.2% efficiency vs 19.2% for the other, a 2.0 percentage point gap.
- • Seraphim S4 Series 430W comes with a 12-year product warranty vs 10 years for the other.
- • First Solar Series 6 Plus 465W has a superior temperature coefficient of -0.28%/°C vs -0.34%/°C, retaining more power in hot climates.
- • First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride) cells while Seraphim S4 Series 430W uses PERC Mono cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Seraphim S4 Series 430W achieves 21.2% module efficiency compared to First Solar Series 6 Plus 465W's 19.2%, meaning Seraphim S4 Series 430W converts 2.0 percentage points more sunlight into electricity per square meter. In practical terms, the First Solar Series 6 Plus 465W produces 187.9 watts per square meter of panel area while the Seraphim S4 Series 430W produces 220.2 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 First Solar Series 6 Plus 465W delivers 465W per panel versus 430W for the Seraphim S4 Series 430W, a 35W difference per module. To build an 8 kW residential system, you would need 18 First Solar Series 6 Plus 465W panels or 19 Seraphim S4 Series 430W 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 First Solar Series 6 Plus 465W has a temperature coefficient of -0.28%/°C versus -0.34%/°C for the Seraphim S4 Series 430W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the First Solar Series 6 Plus 465W retains 94.4% 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 First Solar Series 6 Plus 465W is backed by a 10-year product warranty and 30-year performance guarantee, while the Seraphim S4 Series 430W offers 12-year product and 25-year performance coverage. The Seraphim S4 Series 430W provides 2 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (1.5% first year then 0.5%/year for First Solar Series 6 Plus 465W; 1.5% first year then 0.5%/year for Seraphim S4 Series 430W), after 25 years the First Solar Series 6 Plus 465W should retain approximately 86.5% of original output versus 86.5% for the Seraphim S4 Series 430W. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The First Solar Series 6 Plus 465W measures 2009×1232×49mm and weighs 34.5 kg, while the Seraphim S4 Series 430W measures 1722×1134×30mm at 21 kg. 2.48 m² of panel area for the First Solar Series 6 Plus 465W versus 1.95 m² for the Seraphim S4 Series 430W. The Seraphim S4 Series 430W is 13.5 kg lighter per panel, which reduces structural load requirements on the roof and makes handling easier during installation. For a 20-panel system, that is a total weight difference of 270 kg. The more compact Seraphim S4 Series 430W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | First Solar Series 6 Plus 465W | Seraphim S4 Series 430W |
|---|---|---|
| Power | 465W | 430W |
| Efficiency | 19.2% | 21.2% |
| Power Density | 17.5 W/sq ft | 20.5 W/sq ft |
| Cell Type | CdTe (Cadmium Telluride) | PERC Mono |
| Bifacial | No | No |
| Weight | 34.5 kg | 21 kg |
| Temp Coefficient | -0.28%/°C | -0.34%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 4000 Pa | 2400 Pa |
| Product Warranty | 10 years | 12 years |
| Performance Warranty | 30 years | 25 years |
| Degradation (Year 1) | 1.5% | 1.5% |
| Annual Degradation | 0.5% | 0.5% |
| Country | United States | China |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Seraphim S4 Series 430WThe Seraphim S4 Series 430W achieves 21.2% efficiency versus 19.2% — a 2.0 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: First Solar Series 6 Plus 465WThe First Solar Series 6 Plus 465W has a better temperature coefficient of -0.28%/°C versus -0.34%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.4% of rated power versus 93.2%. This is a meaningful difference in hot states like Arizona, Texas, and Florida.
3. Durability & Warranty
Winner: Seraphim S4 Series 430WSeraphim S4 Series 430W leads with a 12-year product warranty versus 10 years. After 25 years, expect 86.5% vs 86.5% of original output for First Solar Series 6 Plus 465W and Seraphim S4 Series 430W respectively.
4. Power Output
Winner: First Solar Series 6 Plus 465WThe First Solar Series 6 Plus 465W delivers 465W versus 430W per panel — 35W more. For an 8 kW system, you need 18 panels with the higher-wattage option versus 19 panels, saving 1 panels and the associated racking and labor costs.
5. Cell Technology
Winner: First Solar Series 6 Plus 465WThe First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride): CdTe (Cadmium Telluride). The Seraphim S4 Series 430W uses PERC Mono: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. CdTe (Cadmium Telluride) represents a newer generation technology with a longer performance runway as manufacturing matures.
First Solar Series 6 Plus 465W
The Series 6 Plus delivers 465W using First Solar's proven CdTe thin-film technology, manufactured in the United States.
Pros
- + Proven US thin-film technology
- + Excellent temperature coefficient
- + Environmentally responsible
- + Strong bankability
Cons
- - Lower efficiency
- - Very heavy panel
- - Not suitable for residential
Seraphim S4 Series 430W
The Seraphim S4 Series delivers 430W using proven PERC technology at a competitive price point for residential installations.
Pros
- + Competitive pricing
- + Proven PERC technology
- + Compact design
- + Good value
Cons
- - Standard PERC efficiency
- - Shorter warranty period
- - Limited US presence
Choose First Solar Series 6 Plus 465W If...
- ✓ 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
- ✓ Large commercial and utility projects wanting proven US thin-film technology.
Choose Seraphim S4 Series 430W If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ Long-term warranty protection is a top priority and you plan to stay in your home for 12+ years
- ✓ Budget residential installations seeking competitive PERC pricing.
Our Recommendation
Both the First Solar Series 6 Plus 465W and Seraphim S4 Series 430W are excellent solar panel options, and the margin between them is narrow. The Seraphim S4 Series 430W wins 2 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, First Solar Series 6 Plus 465W or Seraphim S4 Series 430W?
The Seraphim S4 Series 430W wins this comparison by a narrow margin. It leads in efficiency (21.2% vs 19.2%) and matches or exceeds on warranty (12 vs 10 years). For most residential installations, the Seraphim S4 Series 430W is the stronger choice.
Which panel is more efficient, First Solar Series 6 Plus 465W or Seraphim S4 Series 430W?
The Seraphim S4 Series 430W 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 2.0 percentage points translates to approximately 35W per panel under standard test conditions.
Which has a better warranty, First Solar Series 6 Plus 465W or Seraphim S4 Series 430W?
The First Solar Series 6 Plus 465W comes with a 10-year product warranty and 30-year performance guarantee. The Seraphim S4 Series 430W offers 12-year product and 25-year performance warranties. Seraphim S4 Series 430W provides 2 additional years of product coverage.
Which panel performs better in hot weather?
The First Solar Series 6 Plus 465W has a temperature coefficient of -0.28%/°C and the Seraphim S4 Series 430W is -0.34%/°C. First Solar Series 6 Plus 465W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many First Solar Series 6 Plus 465W vs Seraphim S4 Series 430W panels do I need for an 8 kW system?
For an 8 kW system: you need 18 First Solar Series 6 Plus 465W panels (465W each) or 19 Seraphim S4 Series 430W panels (430W each). The First Solar Series 6 Plus 465W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026