First Solar Series 6 Plus 465W vs Solaria PowerXT 430R
The Solaria PowerXT 430R wins this comparison by a decisive margin. It leads in efficiency (21.3% vs 19.2%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Solaria PowerXT 430R is the stronger choice.
Key Differences
- • First Solar Series 6 Plus 465W is rated at 465W while Solaria PowerXT 430R is rated at 430W, a 35W difference.
- • Solaria PowerXT 430R achieves 21.3% efficiency vs 19.2% for the other, a 2.1 percentage point gap.
- • Solaria PowerXT 430R comes with a 25-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 Solaria PowerXT 430R uses Shingled Mono PERC cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Solaria PowerXT 430R achieves 21.3% module efficiency compared to First Solar Series 6 Plus 465W's 19.2%, meaning Solaria PowerXT 430R converts 2.1 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 Solaria PowerXT 430R produces 212.9 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 430W for the Solaria PowerXT 430R, 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 Solaria PowerXT 430R 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 Solaria PowerXT 430R. 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 Solaria PowerXT 430R offers 25-year product and 25-year performance coverage. The Solaria PowerXT 430R provides 15 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 0.4%/year for Solaria PowerXT 430R), after 25 years the First Solar Series 6 Plus 465W should retain approximately 86.5% of original output versus 88.9% for the Solaria PowerXT 430R. This 2.4 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The First Solar Series 6 Plus 465W measures 2009×1232×49mm and weighs 34.5 kg, while the Solaria PowerXT 430R measures 1879×1075×40mm at 22 kg. 2.48 m² of panel area for the First Solar Series 6 Plus 465W versus 2.02 m² for the Solaria PowerXT 430R. The Solaria PowerXT 430R is 12.5 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 250 kg. The more compact Solaria PowerXT 430R may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | First Solar Series 6 Plus 465W | Solaria PowerXT 430R |
|---|---|---|
| Power | 465W | 430W |
| Efficiency | 19.2% | 21.3% |
| Power Density | 17.5 W/sq ft | 19.8 W/sq ft |
| Cell Type | CdTe (Cadmium Telluride) | Shingled Mono PERC |
| Bifacial | No | No |
| Weight | 34.5 kg | 22 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 | 25 years |
| Performance Warranty | 30 years | 25 years |
| Degradation (Year 1) | 1.5% | 1.5% |
| Annual Degradation | 0.5% | 0.4% |
| Country | United States | USA |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Solaria PowerXT 430RThe Solaria PowerXT 430R achieves 21.3% efficiency versus 19.2% — a 2.1 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 1.1 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: Solaria PowerXT 430RSolaria PowerXT 430R leads with a 25-year product warranty versus 10 years. Solaria PowerXT 430R degrades more slowly at 0.4% per year versus 0.5%. After 25 years, expect 86.5% vs 88.9% of original output for First Solar Series 6 Plus 465W and Solaria PowerXT 430R 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 Solaria PowerXT 430R uses Shingled Mono PERC: 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
Solaria PowerXT 430R
The Solaria PowerXT 430R is a US-manufactured shingled-cell solar panel that eliminates traditional busbars and cell gaps to maximize active cell area and deliver a sleek, uniform all-black appearance. Shingled cell technology overlaps cell strips like roof shingles, reducing inactive area by approximately 50% compared to traditional half-cut designs. This results in more power from the same panel area and improved shade tolerance due to the shingled cell interconnection pattern. Made in Fremont, California, the PowerXT qualifies for domestic content bonus ITC credits.
Pros
- + Shingled cell technology — more power per square foot than traditional panels
- + Sleek all-black appearance with no visible busbars or cell gaps
- + Made in USA (Fremont, CA) — qualifies for domestic content ITC bonus
- + Enhanced shade tolerance from shingled interconnection pattern
- + 25-year product and performance warranties
- + No hot spots — shingled design eliminates busbar-related failures
Cons
- - Premium pricing for US-manufactured shingled technology
- - 430W is competitive but not class-leading for this panel size
- - Shingled cell technology has less field history than traditional designs
- - Limited to Solaria-authorized installer network
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 Solaria PowerXT 430R 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 25+ years
- ✓ You want maximum output retention over the system's 25-30 year lifespan
- ✓ US homeowners who prioritize American-made panels with a premium all-black aesthetic and want domestic content ITC bonus eligibility.
Our Recommendation
The Solaria PowerXT 430R is the decisive winner in this solar panel comparison, outperforming the First Solar Series 6 Plus 465W in 2 of 5 dimensions. Unless you have a specific requirement that the First Solar Series 6 Plus 465W uniquely addresses, the Solaria PowerXT 430R is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, First Solar Series 6 Plus 465W or Solaria PowerXT 430R?
The Solaria PowerXT 430R wins this comparison by a decisive margin. It leads in efficiency (21.3% vs 19.2%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Solaria PowerXT 430R is the stronger choice.
Which panel is more efficient, First Solar Series 6 Plus 465W or Solaria PowerXT 430R?
The Solaria PowerXT 430R 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 35W per panel under standard test conditions.
Which has a better warranty, First Solar Series 6 Plus 465W or Solaria PowerXT 430R?
The First Solar Series 6 Plus 465W comes with a 10-year product warranty and 30-year performance guarantee. The Solaria PowerXT 430R offers 25-year product and 25-year performance warranties. Solaria PowerXT 430R provides 15 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 Solaria PowerXT 430R 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 Solaria PowerXT 430R 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 Solaria PowerXT 430R 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