Trina Solar Vertex S 420W vs First Solar Series 6 Plus 465W
The Trina Solar Vertex S 420W wins this comparison by a clear margin. It leads in efficiency (21.3% vs 19.2%) and matches or exceeds on warranty (15 vs 10 years). For most residential installations, the Trina Solar Vertex S 420W is the stronger choice.
Key Differences
- • Trina Solar Vertex S 420W is rated at 420W while First Solar Series 6 Plus 465W is rated at 465W, a 45W difference.
- • Trina Solar Vertex S 420W achieves 21.3% efficiency vs 19.2% for the other, a 2.1 percentage point gap.
- • Trina Solar Vertex S 420W comes with a 15-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.
- • Trina Solar Vertex S 420W uses PERC Mono cells while First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride) cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Trina Solar Vertex S 420W achieves 21.3% module efficiency compared to First Solar Series 6 Plus 465W's 19.2%, meaning Trina Solar Vertex S 420W converts 2.1 percentage points more sunlight into electricity per square meter. In practical terms, the Trina Solar Vertex S 420W produces 210.2 watts per square meter of panel area while the First Solar Series 6 Plus 465W produces 187.9 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 420W for the Trina Solar Vertex S 420W, a 45W difference per module. To build an 8 kW residential system, you would need 20 Trina Solar Vertex S 420W panels or 18 First Solar Series 6 Plus 465W 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 First Solar Series 6 Plus 465W has a temperature coefficient of -0.28%/°C versus -0.34%/°C for the Trina Solar Vertex S 420W. 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 Trina Solar Vertex S 420W is backed by a 15-year product warranty and 25-year performance guarantee, while the First Solar Series 6 Plus 465W offers 10-year product and 30-year performance coverage. The Trina Solar Vertex S 420W provides 5 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 Trina Solar Vertex S 420W; 1.5% first year then 0.5%/year for First Solar Series 6 Plus 465W), after 25 years the Trina Solar Vertex S 420W should retain approximately 86.5% of original output versus 86.5% for the First Solar Series 6 Plus 465W. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The Trina Solar Vertex S 420W measures 1762×1134×30mm and weighs 21.8 kg, while the First Solar Series 6 Plus 465W measures 2009×1232×49mm at 34.5 kg. 2.00 m² of panel area for the Trina Solar Vertex S 420W versus 2.48 m² for the First Solar Series 6 Plus 465W. The Trina Solar Vertex S 420W is 12.7 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 254 kg. The more compact Trina Solar Vertex S 420W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | Trina Solar Vertex S 420W | First Solar Series 6 Plus 465W |
|---|---|---|
| Power | 420W | 465W |
| Efficiency | 21.3% | 19.2% |
| Power Density | 19.5 W/sq ft | 17.5 W/sq ft |
| Cell Type | PERC Mono | CdTe (Cadmium Telluride) |
| Bifacial | No | No |
| Weight | 21.8 kg | 34.5 kg |
| Temp Coefficient | -0.34%/°C | -0.28%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 4000 Pa |
| Product Warranty | 15 years | 10 years |
| Performance Warranty | 25 years | 30 years |
| Degradation (Year 1) | 1.5% | 1.5% |
| Annual Degradation | 0.5% | 0.5% |
| Country | China | United States |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Trina Solar Vertex S 420WThe Trina Solar Vertex S 420W achieves 21.3% efficiency versus 19.2% — a 2.1 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: 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: Trina Solar Vertex S 420WTrina Solar Vertex S 420W leads with a 15-year product warranty versus 10 years. After 25 years, expect 86.5% vs 86.5% of original output for Trina Solar Vertex S 420W and First Solar Series 6 Plus 465W respectively.
4. Power Output
Winner: First Solar Series 6 Plus 465WThe First Solar Series 6 Plus 465W delivers 465W versus 420W 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: First Solar Series 6 Plus 465WThe Trina Solar Vertex S 420W uses PERC Mono: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. The First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride): CdTe (Cadmium Telluride). CdTe (Cadmium Telluride) represents a newer generation technology with a longer performance runway as manufacturing matures.
Trina Solar Vertex S 420W
The Vertex S (DE09R.08) is a proven PERC residential panel offering 420W with 144 half-cut cells in a compact form factor with reliable Trina Solar quality.
Pros
- + Proven PERC reliability
- + Competitive pricing
- + 144 half-cut cells for shade tolerance
- + Widely available
Cons
- - Lower efficiency than N-type
- - Higher degradation
- - PERC technology limitations
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
Choose Trina Solar Vertex S 420W 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 15+ years
- ✓ Cost-effective residential installations with proven technology.
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.
Our Recommendation
We recommend the Trina Solar Vertex S 420W for most buyers in this comparison. It wins 2 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The First Solar Series 6 Plus 465W remains a good product, but the Trina Solar Vertex S 420W delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, Trina Solar Vertex S 420W or First Solar Series 6 Plus 465W?
The Trina Solar Vertex S 420W wins this comparison by a clear margin. It leads in efficiency (21.3% vs 19.2%) and matches or exceeds on warranty (15 vs 10 years). For most residential installations, the Trina Solar Vertex S 420W is the stronger choice.
Which panel is more efficient, Trina Solar Vertex S 420W or First Solar Series 6 Plus 465W?
The Trina Solar Vertex S 420W at 21.3% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 2.1 percentage points translates to approximately 45W per panel under standard test conditions.
Which has a better warranty, Trina Solar Vertex S 420W or First Solar Series 6 Plus 465W?
The Trina Solar Vertex S 420W comes with a 15-year product warranty and 25-year performance guarantee. The First Solar Series 6 Plus 465W offers 10-year product and 30-year performance warranties. Trina Solar Vertex S 420W provides 5 additional years of product coverage.
Which panel performs better in hot weather?
The Trina Solar Vertex S 420W has a temperature coefficient of -0.34%/°C and the First Solar Series 6 Plus 465W is -0.28%/°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 Trina Solar Vertex S 420W vs First Solar Series 6 Plus 465W panels do I need for an 8 kW system?
For an 8 kW system: you need 20 Trina Solar Vertex S 420W panels (420W each) or 18 First Solar Series 6 Plus 465W panels (465W 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