Maxeon Maxeon 6 AC 440W vs First Solar Series 6 Plus 465W
The Maxeon Maxeon 6 AC 440W wins this comparison by a decisive margin. It leads in efficiency (22.5% vs 19.2%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Maxeon Maxeon 6 AC 440W is the stronger choice.
Key Differences
- • Maxeon Maxeon 6 AC 440W is rated at 440W while First Solar Series 6 Plus 465W is rated at 465W, a 25W difference.
- • Maxeon Maxeon 6 AC 440W achieves 22.5% efficiency vs 19.2% for the other, a 3.3 percentage point gap.
- • Maxeon Maxeon 6 AC 440W comes with a 25-year product warranty vs 10 years for the other.
- • Maxeon Maxeon 6 AC 440W has a superior temperature coefficient of -0.27%/°C vs -0.28%/°C, retaining more power in hot climates.
- • Maxeon Maxeon 6 AC 440W uses IBC (Interdigitated Back Contact) cells while First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride) cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Maxeon Maxeon 6 AC 440W achieves 22.5% module efficiency compared to First Solar Series 6 Plus 465W's 19.2%, meaning Maxeon Maxeon 6 AC 440W converts 3.3 percentage points more sunlight into electricity per square meter. In practical terms, the Maxeon Maxeon 6 AC 440W produces 203.5 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 440W for the Maxeon Maxeon 6 AC 440W, a 25W difference per module. To build an 8 kW residential system, you would need 19 Maxeon Maxeon 6 AC 440W panels or 18 First Solar Series 6 Plus 465W 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 Maxeon Maxeon 6 AC 440W has a temperature coefficient of -0.27%/°C versus -0.28%/°C for the First Solar Series 6 Plus 465W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Maxeon Maxeon 6 AC 440W retains 94.6% of its rated power while the other retains 94.4%. While the numerical gap is modest, it still accumulates over decades of summer production, especially in southern latitudes with prolonged peak heat hours.
Warranty Coverage
The Maxeon Maxeon 6 AC 440W is backed by a 25-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 Maxeon Maxeon 6 AC 440W provides 15 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (0.25% first year then 0.25%/year for Maxeon Maxeon 6 AC 440W; 1.5% first year then 0.5%/year for First Solar Series 6 Plus 465W), after 25 years the Maxeon Maxeon 6 AC 440W should retain approximately 93.8% of original output versus 86.5% for the First Solar Series 6 Plus 465W. This 7.3 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The Maxeon Maxeon 6 AC 440W measures 2067×1046×30mm and weighs 22 kg, while the First Solar Series 6 Plus 465W measures 2009×1232×49mm at 34.5 kg. 2.16 m² of panel area for the Maxeon Maxeon 6 AC 440W versus 2.48 m² for the First Solar Series 6 Plus 465W. The Maxeon Maxeon 6 AC 440W 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 Maxeon Maxeon 6 AC 440W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | Maxeon Maxeon 6 AC 440W | First Solar Series 6 Plus 465W |
|---|---|---|
| Power | 440W | 465W |
| Efficiency | 22.5% | 19.2% |
| Power Density | 18.9 W/sq ft | 17.5 W/sq ft |
| Cell Type | IBC (Interdigitated Back Contact) | CdTe (Cadmium Telluride) |
| Bifacial | Yes | No |
| Weight | 22 kg | 34.5 kg |
| Temp Coefficient | -0.27%/°C | -0.28%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 3600 Pa | 4000 Pa |
| Product Warranty | 25 years | 10 years |
| Performance Warranty | 25 years | 30 years |
| Degradation (Year 1) | 0.25% | 1.5% |
| Annual Degradation | 0.25% | 0.5% |
| Country | Malaysia | United States |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Maxeon Maxeon 6 AC 440WThe Maxeon Maxeon 6 AC 440W achieves 22.5% efficiency versus 19.2% — a 3.3 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.8 kW more total system capacity, or 4 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: Maxeon Maxeon 6 AC 440WThe Maxeon Maxeon 6 AC 440W has a better temperature coefficient of -0.27%/°C versus -0.28%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.6% of rated power versus 94.4%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: Maxeon Maxeon 6 AC 440WMaxeon Maxeon 6 AC 440W leads with a 25-year product warranty versus 10 years. Maxeon Maxeon 6 AC 440W degrades more slowly at 0.25% per year versus 0.5%. After 25 years, expect 93.8% vs 86.5% of original output for Maxeon Maxeon 6 AC 440W 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 440W per panel — 25W 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: Maxeon Maxeon 6 AC 440WThe Maxeon Maxeon 6 AC 440W uses IBC (Interdigitated Back Contact): IBC (Interdigitated Back Contact) moves all electrical contacts to the rear of the cell, maximizing front-side light capture for the highest possible efficiency. The First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride): CdTe (Cadmium Telluride). IBC (Interdigitated Back Contact) represents a newer generation technology with a longer performance runway as manufacturing matures.
Maxeon Maxeon 6 AC 440W
The Maxeon 6 AC 440W is designed for commercial applications, delivering 440W with IBC technology in a commercial form factor with integrated microinverter option.
Pros
- + IBC technology for commercial use
- + Strong 22.5% efficiency
- + Low degradation
- + Excellent shade tolerance
Cons
- - Commercial pricing
- - Larger form factor
- - Limited residential application
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 Maxeon Maxeon 6 AC 440W 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 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
- ✓ Commercial rooftop installations seeking premium IBC performance.
Choose First Solar Series 6 Plus 465W If...
- ✓ You want fewer panels to reach your target system size, reducing racking and labor costs
- ✓ Large commercial and utility projects wanting proven US thin-film technology.
Our Recommendation
The Maxeon Maxeon 6 AC 440W is the decisive winner in this solar panel comparison, outperforming the First Solar Series 6 Plus 465W in 4 of 5 dimensions. Unless you have a specific requirement that the First Solar Series 6 Plus 465W uniquely addresses, the Maxeon Maxeon 6 AC 440W is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, Maxeon Maxeon 6 AC 440W or First Solar Series 6 Plus 465W?
The Maxeon Maxeon 6 AC 440W wins this comparison by a decisive margin. It leads in efficiency (22.5% vs 19.2%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Maxeon Maxeon 6 AC 440W is the stronger choice.
Which panel is more efficient, Maxeon Maxeon 6 AC 440W or First Solar Series 6 Plus 465W?
The Maxeon Maxeon 6 AC 440W at 22.5% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 3.3 percentage points translates to approximately 25W per panel under standard test conditions.
Which has a better warranty, Maxeon Maxeon 6 AC 440W or First Solar Series 6 Plus 465W?
The Maxeon Maxeon 6 AC 440W comes with a 25-year product warranty and 25-year performance guarantee. The First Solar Series 6 Plus 465W offers 10-year product and 30-year performance warranties. Maxeon Maxeon 6 AC 440W provides 15 additional years of product coverage.
Which panel performs better in hot weather?
The Maxeon Maxeon 6 AC 440W has a temperature coefficient of -0.27%/°C and the First Solar Series 6 Plus 465W is -0.28%/°C. Maxeon Maxeon 6 AC 440W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many Maxeon Maxeon 6 AC 440W vs First Solar Series 6 Plus 465W panels do I need for an 8 kW system?
For an 8 kW system: you need 19 Maxeon Maxeon 6 AC 440W panels (440W 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