First Solar Series 6 Plus 465W vs Waaree WS-440
The Waaree WS-440 wins this comparison by a clear margin. It leads in efficiency (21.8% vs 19.2%) and matches or exceeds on warranty (12 vs 10 years). For most residential installations, the Waaree WS-440 is the stronger choice.
Key Differences
- • First Solar Series 6 Plus 465W is rated at 465W while Waaree WS-440 is rated at 440W, a 25W difference.
- • Waaree WS-440 achieves 21.8% efficiency vs 19.2% for the other, a 2.6 percentage point gap.
- • Waaree WS-440 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 -0.3%/°C, retaining more power in hot climates.
- • First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride) cells while Waaree WS-440 uses TOPCon N-type cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Waaree WS-440 achieves 21.8% module efficiency compared to First Solar Series 6 Plus 465W's 19.2%, meaning Waaree WS-440 converts 2.6 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 Waaree WS-440 produces 225.3 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 Waaree WS-440, a 25W difference per module. To build an 8 kW residential system, you would need 18 First Solar Series 6 Plus 465W panels or 19 Waaree WS-440 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 -0.3%/°C for the Waaree WS-440. 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 94.0%. 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 First Solar Series 6 Plus 465W is backed by a 10-year product warranty and 30-year performance guarantee, while the Waaree WS-440 offers 12-year product and 25-year performance coverage. The Waaree WS-440 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% first year then 0.4%/year for Waaree WS-440), after 25 years the First Solar Series 6 Plus 465W should retain approximately 86.5% of original output versus 89.4% for the Waaree WS-440. This 2.9 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 Waaree WS-440 measures 1722×1134×30mm at 21.5 kg. 2.48 m² of panel area for the First Solar Series 6 Plus 465W versus 1.95 m² for the Waaree WS-440. The Waaree WS-440 is 13.0 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 260 kg. The more compact Waaree WS-440 may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | First Solar Series 6 Plus 465W | Waaree WS-440 |
|---|---|---|
| Power | 465W | 440W |
| Efficiency | 19.2% | 21.8% |
| Power Density | 17.5 W/sq ft | 20.9 W/sq ft |
| Cell Type | CdTe (Cadmium Telluride) | TOPCon N-type |
| Bifacial | No | No |
| Weight | 34.5 kg | 21.5 kg |
| Temp Coefficient | -0.28%/°C | -0.3%/°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% |
| Annual Degradation | 0.5% | 0.4% |
| Country | United States | India |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Waaree WS-440The Waaree WS-440 achieves 21.8% efficiency versus 19.2% — a 2.6 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: First Solar Series 6 Plus 465WThe First Solar Series 6 Plus 465W has a better temperature coefficient of -0.28%/°C versus -0.3%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.4% of rated power versus 94.0%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: Waaree WS-440Waaree WS-440 leads with a 12-year product warranty versus 10 years. Waaree WS-440 degrades more slowly at 0.4% per year versus 0.5%. After 25 years, expect 86.5% vs 89.4% of original output for First Solar Series 6 Plus 465W and Waaree WS-440 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: Waaree WS-440The First Solar Series 6 Plus 465W uses CdTe (Cadmium Telluride): CdTe (Cadmium Telluride). The Waaree WS-440 uses TOPCon N-type: TOPCon (Tunnel Oxide Passivated Contact) adds a thin tunnel oxide layer to reduce recombination losses, achieving higher efficiency than PERC while being manufacturable on existing production lines. TOPCon N-type 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
Waaree WS-440
The Waaree WS-440 is a 440W residential-format TOPCon N-type panel in the standard 108-cell configuration, manufactured at Waaree's state-of-the-art facilities in Gujarat, India. At 21.8% efficiency, it competes directly with Chinese TOPCon panels while offering Indian supply chain diversification. The standard 1722 x 1134mm form factor ensures compatibility with all major racking systems. Waaree's rapidly expanding US distribution makes this one of the most accessible Indian-made panels in the North American market.
Pros
- + Indian-manufactured — non-Chinese supply chain alternative
- + 21.8% efficiency competitive with Chinese TOPCon leaders
- + Standard 108-cell residential format — universal racking compatibility
- + -0.30%/°C temp coefficient for hot climate performance
- + Highly competitive pricing — among the lowest-cost TOPCon panels
- + Waaree's expanding US distribution improves availability
Cons
- - 12-year product warranty shorter than 25-year leaders
- - Indian manufacturing quality perception still developing vs established brands
- - US installer familiarity and support network still growing
- - No bifacial option in this residential format
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 Waaree WS-440 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
- ✓ You want maximum output retention over the system's 25-30 year lifespan
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Cost-conscious residential installers seeking high-efficiency TOPCon panels from a non-Chinese manufacturer at a competitive price point.
Our Recommendation
We recommend the Waaree WS-440 for most buyers in this comparison. It wins 3 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 Waaree WS-440 delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, First Solar Series 6 Plus 465W or Waaree WS-440?
The Waaree WS-440 wins this comparison by a clear margin. It leads in efficiency (21.8% vs 19.2%) and matches or exceeds on warranty (12 vs 10 years). For most residential installations, the Waaree WS-440 is the stronger choice.
Which panel is more efficient, First Solar Series 6 Plus 465W or Waaree WS-440?
The Waaree WS-440 at 21.8% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 2.6 percentage points translates to approximately 25W per panel under standard test conditions.
Which has a better warranty, First Solar Series 6 Plus 465W or Waaree WS-440?
The First Solar Series 6 Plus 465W comes with a 10-year product warranty and 30-year performance guarantee. The Waaree WS-440 offers 12-year product and 25-year performance warranties. Waaree WS-440 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 Waaree WS-440 is -0.3%/°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 Waaree WS-440 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 Waaree WS-440 panels (440W each). The First Solar Series 6 Plus 465W requires fewer panels, saving on racking hardware and installation labor.
Related Resources
Last updated: February 2026