JA Solar DeepBlue 3.0 400W vs Canadian Solar CS6R 420W
The Canadian Solar CS6R 420W wins this comparison by a narrow margin. It leads in efficiency (21% vs 20.9%) and matches or exceeds on warranty (12 vs 12 years). For most residential installations, the Canadian Solar CS6R 420W is the stronger choice.
Key Differences
- • JA Solar DeepBlue 3.0 400W is rated at 400W while Canadian Solar CS6R 420W is rated at 420W, a 20W difference.
- • Canadian Solar CS6R 420W achieves 21% efficiency vs 20.9% for the other, a 0.1 percentage point gap.
- • Both carry matching 12-year product warranties.
- • Canadian Solar CS6R 420W has a superior temperature coefficient of -0.34%/°C vs -0.35%/°C, retaining more power in hot climates.
Specifications Breakdown
Module Efficiency
The Canadian Solar CS6R 420W achieves 21% module efficiency compared to JA Solar DeepBlue 3.0 400W's 20.9%, meaning Canadian Solar CS6R 420W converts 0.1 percentage points more sunlight into electricity per square meter. In practical terms, the JA Solar DeepBlue 3.0 400W produces 204.8 watts per square meter of panel area while the Canadian Solar CS6R 420W produces 215.1 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 Canadian Solar CS6R 420W delivers 420W per panel versus 400W for the JA Solar DeepBlue 3.0 400W, a 20W difference per module. To build an 8 kW residential system, you would need 20 JA Solar DeepBlue 3.0 400W panels or 20 Canadian Solar CS6R 420W 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 Canadian Solar CS6R 420W has a temperature coefficient of -0.34%/°C versus -0.35%/°C for the JA Solar DeepBlue 3.0 400W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Canadian Solar CS6R 420W retains 93.2% of its rated power while the other retains 93.0%. 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 JA Solar DeepBlue 3.0 400W is backed by a 12-year product warranty and 25-year performance guarantee, while the Canadian Solar CS6R 420W offers 12-year product and 25-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (2% first year then 0.5%/year for JA Solar DeepBlue 3.0 400W; 1.5% first year then 0.5%/year for Canadian Solar CS6R 420W), after 25 years the JA Solar DeepBlue 3.0 400W should retain approximately 86.0% of original output versus 86.5% for the Canadian Solar CS6R 420W. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The JA Solar DeepBlue 3.0 400W measures 1722×1134×30mm and weighs 20.5 kg, while the Canadian Solar CS6R 420W measures 1722×1134×30mm at 21 kg. 1.95 m² of panel area for the JA Solar DeepBlue 3.0 400W versus 1.95 m² for the Canadian Solar CS6R 420W. Their weights are closely matched, so neither panel imposes a significantly different structural load on the mounting system. Similar footprints mean both panels fit comparably on standard residential rooftop configurations.
Specification Comparison
| Specification | JA Solar DeepBlue 3.0 400W | Canadian Solar CS6R 420W |
|---|---|---|
| Power | 400W | 420W |
| Efficiency | 20.9% | 21% |
| Power Density | 19.0 W/sq ft | 20.0 W/sq ft |
| Cell Type | PERC Mono | PERC Mono |
| Bifacial | No | No |
| Weight | 20.5 kg | 21 kg |
| Temp Coefficient | -0.35%/°C | -0.34%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 12 years | 12 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 2% | 1.5% |
| Annual Degradation | 0.5% | 0.5% |
| Country | China | China |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Canadian Solar CS6R 420WThe Canadian Solar CS6R 420W achieves 21% efficiency versus 20.9% — a 0.1 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.6 kW more total system capacity, or 3 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: Canadian Solar CS6R 420WThe Canadian Solar CS6R 420W has a better temperature coefficient of -0.34%/°C versus -0.35%/°C. On a 45°C summer day (20°C above STC), the winner retains 93.2% of rated power versus 93.0%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: TieBoth panels offer identical 12-year product warranties and 0.5% annual degradation. Neither has a durability advantage.
4. Power Output
Winner: Canadian Solar CS6R 420WThe Canadian Solar CS6R 420W delivers 420W versus 400W per panel — 20W more. For an 8 kW system, you need 20 panels with the higher-wattage option versus 20 panels, saving 0 panels and the associated racking and labor costs.
5. Cell Technology
Winner: TieBoth panels use PERC Mono cell technology. No technology advantage for either product.
JA Solar DeepBlue 3.0 400W
The DeepBlue 3.0 is an affordable 400W PERC panel ideal for budget-conscious residential solar installations.
Pros
- + Very affordable
- + Lightweight design
- + Easy installation
- + Proven technology
Cons
- - Lower efficiency
- - Higher degradation rate
- - Shorter warranty
Canadian Solar CS6R 420W
The CS6R is Canadian Solar's residential PERC workhorse delivering 420W in a compact, roof-friendly form factor.
Pros
- + Compact residential size
- + Affordable pricing
- + Proven track record
- + Easy installation
Cons
- - Older PERC technology
- - Standard performance
- - Higher degradation
Choose JA Solar DeepBlue 3.0 400W If...
- ✓ Budget installations where cost per watt is the primary concern.
Choose Canadian Solar CS6R 420W If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ 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
- ✓ Budget residential installations from a bankable Tier 1 brand.
Our Recommendation
Both the JA Solar DeepBlue 3.0 400W and Canadian Solar CS6R 420W are excellent solar panel options, and the margin between them is narrow. The Canadian Solar CS6R 420W wins 3 of 5 comparison dimensions by a slim margin. Your decision may come down to local pricing, installer availability, and which specific performance metrics matter most for your project. Either product is a solid investment.
Frequently Asked Questions
Which is better, JA Solar DeepBlue 3.0 400W or Canadian Solar CS6R 420W?
The Canadian Solar CS6R 420W wins this comparison by a narrow margin. It leads in efficiency (21% vs 20.9%) and matches or exceeds on warranty (12 vs 12 years). For most residential installations, the Canadian Solar CS6R 420W is the stronger choice.
Which panel is more efficient, JA Solar DeepBlue 3.0 400W or Canadian Solar CS6R 420W?
The Canadian Solar CS6R 420W at 21% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.1 percentage points translates to approximately 20W per panel under standard test conditions.
Which has a better warranty, JA Solar DeepBlue 3.0 400W or Canadian Solar CS6R 420W?
The JA Solar DeepBlue 3.0 400W comes with a 12-year product warranty and 25-year performance guarantee. The Canadian Solar CS6R 420W offers 12-year product and 25-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The JA Solar DeepBlue 3.0 400W has a temperature coefficient of -0.35%/°C and the Canadian Solar CS6R 420W is -0.34%/°C. Canadian Solar CS6R 420W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many JA Solar DeepBlue 3.0 400W vs Canadian Solar CS6R 420W panels do I need for an 8 kW system?
For an 8 kW system: you need 20 JA Solar DeepBlue 3.0 400W panels (400W each) or 20 Canadian Solar CS6R 420W panels (420W each). The Canadian Solar CS6R 420W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026