First Solar Series 6 Plus 465W vs Tongwei THN-PE14M10 450W
The Tongwei THN-PE14M10 450W wins this comparison by a clear margin. It leads in efficiency (21.5% vs 19.2%) and matches or exceeds on warranty (12 vs 10 years). For most residential installations, the Tongwei THN-PE14M10 450W is the stronger choice.
Key Differences
- • First Solar Series 6 Plus 465W is rated at 465W while Tongwei THN-PE14M10 450W is rated at 450W, a 15W difference.
- • Tongwei THN-PE14M10 450W achieves 21.5% efficiency vs 19.2% for the other, a 2.3 percentage point gap.
- • Tongwei THN-PE14M10 450W 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 Tongwei THN-PE14M10 450W uses PERC Mono cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Tongwei THN-PE14M10 450W achieves 21.5% module efficiency compared to First Solar Series 6 Plus 465W's 19.2%, meaning Tongwei THN-PE14M10 450W converts 2.3 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 Tongwei THN-PE14M10 450W produces 225.2 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 450W for the Tongwei THN-PE14M10 450W, a 15W difference per module. To build an 8 kW residential system, you would need 18 First Solar Series 6 Plus 465W panels or 18 Tongwei THN-PE14M10 450W 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 First Solar Series 6 Plus 465W has a temperature coefficient of -0.28%/°C versus -0.34%/°C for the Tongwei THN-PE14M10 450W. 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 Tongwei THN-PE14M10 450W offers 12-year product and 25-year performance coverage. The Tongwei THN-PE14M10 450W 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 Tongwei THN-PE14M10 450W), after 25 years the First Solar Series 6 Plus 465W should retain approximately 86.5% of original output versus 86.5% for the Tongwei THN-PE14M10 450W. 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 Tongwei THN-PE14M10 450W measures 1762×1134×30mm at 23 kg. 2.48 m² of panel area for the First Solar Series 6 Plus 465W versus 2.00 m² for the Tongwei THN-PE14M10 450W. The Tongwei THN-PE14M10 450W is 11.5 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 230 kg. The more compact Tongwei THN-PE14M10 450W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | First Solar Series 6 Plus 465W | Tongwei THN-PE14M10 450W |
|---|---|---|
| Power | 465W | 450W |
| Efficiency | 19.2% | 21.5% |
| Power Density | 17.5 W/sq ft | 20.9 W/sq ft |
| Cell Type | CdTe (Cadmium Telluride) | PERC Mono |
| Bifacial | No | No |
| Weight | 34.5 kg | 23 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: Tongwei THN-PE14M10 450WThe Tongwei THN-PE14M10 450W achieves 21.5% efficiency versus 19.2% — a 2.3 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.5 kW more total system capacity, or 3 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: Tongwei THN-PE14M10 450WTongwei THN-PE14M10 450W 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 Tongwei THN-PE14M10 450W respectively.
4. Power Output
Winner: First Solar Series 6 Plus 465WThe First Solar Series 6 Plus 465W delivers 465W versus 450W per panel — 15W more. For an 8 kW system, you need 18 panels with the higher-wattage option versus 18 panels, saving 0 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 Tongwei THN-PE14M10 450W 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
Tongwei THN-PE14M10 450W
Tongwei's THN-PE14M10 delivers 450W using proven PERC technology at a very competitive price point.
Pros
- + Very competitive pricing
- + Good output for size
- + Strong cell technology
- + Growing brand
Cons
- - Less known outside China
- - Standard warranty
- - Limited US distribution
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 Tongwei THN-PE14M10 450W 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
- ✓ Value-focused projects seeking affordable panels from a major cell producer.
Our Recommendation
We recommend the Tongwei THN-PE14M10 450W 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 Tongwei THN-PE14M10 450W delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, First Solar Series 6 Plus 465W or Tongwei THN-PE14M10 450W?
The Tongwei THN-PE14M10 450W wins this comparison by a clear margin. It leads in efficiency (21.5% vs 19.2%) and matches or exceeds on warranty (12 vs 10 years). For most residential installations, the Tongwei THN-PE14M10 450W is the stronger choice.
Which panel is more efficient, First Solar Series 6 Plus 465W or Tongwei THN-PE14M10 450W?
The Tongwei THN-PE14M10 450W 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 2.3 percentage points translates to approximately 15W per panel under standard test conditions.
Which has a better warranty, First Solar Series 6 Plus 465W or Tongwei THN-PE14M10 450W?
The First Solar Series 6 Plus 465W comes with a 10-year product warranty and 30-year performance guarantee. The Tongwei THN-PE14M10 450W offers 12-year product and 25-year performance warranties. Tongwei THN-PE14M10 450W 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 Tongwei THN-PE14M10 450W 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 Tongwei THN-PE14M10 450W 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 18 Tongwei THN-PE14M10 450W panels (450W 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