JA Solar JAM78S30 590W vs Canadian Solar TOPBiHiKu7 580W
The JA Solar JAM78S30 590W wins this comparison by a narrow margin. It leads in efficiency (22.6% vs 22.1%) and matches or exceeds on warranty (15 vs 15 years). For most residential installations, the JA Solar JAM78S30 590W is the stronger choice.
Key Differences
- • JA Solar JAM78S30 590W is rated at 590W while Canadian Solar TOPBiHiKu7 580W is rated at 580W, a 10W difference.
- • JA Solar JAM78S30 590W achieves 22.6% efficiency vs 22.1% for the other, a 0.5 percentage point gap.
- • Both carry matching 15-year product warranties.
- • JA Solar JAM78S30 590W has a superior temperature coefficient of -0.28%/°C vs -0.29%/°C, retaining more power in hot climates.
- • JA Solar JAM78S30 590W uses TOPCon N-type cells while Canadian Solar TOPBiHiKu7 580W uses TOPCon N-type Bifacial cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The JA Solar JAM78S30 590W achieves 22.6% module efficiency compared to Canadian Solar TOPBiHiKu7 580W's 22.1%, meaning JA Solar JAM78S30 590W converts 0.5 percentage points more sunlight into electricity per square meter. In practical terms, the JA Solar JAM78S30 590W produces 218.2 watts per square meter of panel area while the Canadian Solar TOPBiHiKu7 580W produces 224.5 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 JA Solar JAM78S30 590W delivers 590W per panel versus 580W for the Canadian Solar TOPBiHiKu7 580W, a 10W difference per module. To build an 8 kW residential system, you would need 14 JA Solar JAM78S30 590W panels or 14 Canadian Solar TOPBiHiKu7 580W 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 JA Solar JAM78S30 590W has a temperature coefficient of -0.28%/°C versus -0.29%/°C for the Canadian Solar TOPBiHiKu7 580W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the JA Solar JAM78S30 590W retains 94.4% of its rated power while the other retains 94.2%. 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 JAM78S30 590W is backed by a 15-year product warranty and 30-year performance guarantee, while the Canadian Solar TOPBiHiKu7 580W offers 15-year product and 30-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (1% first year then 0.4%/year for JA Solar JAM78S30 590W; 1% first year then 0.4%/year for Canadian Solar TOPBiHiKu7 580W), after 25 years the JA Solar JAM78S30 590W should retain approximately 89.4% of original output versus 89.4% for the Canadian Solar TOPBiHiKu7 580W. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The JA Solar JAM78S30 590W measures 2384×1134×35mm and weighs 31 kg, while the Canadian Solar TOPBiHiKu7 580W measures 2278×1134×35mm at 28.5 kg. 2.70 m² of panel area for the JA Solar JAM78S30 590W versus 2.58 m² for the Canadian Solar TOPBiHiKu7 580W. The Canadian Solar TOPBiHiKu7 580W is 2.5 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 50 kg. The more compact Canadian Solar TOPBiHiKu7 580W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | JA Solar JAM78S30 590W | Canadian Solar TOPBiHiKu7 580W |
|---|---|---|
| Power | 590W | 580W |
| Efficiency | 22.6% | 22.1% |
| Power Density | 20.3 W/sq ft | 20.9 W/sq ft |
| Cell Type | TOPCon N-type | TOPCon N-type Bifacial |
| Bifacial | No | Yes |
| Weight | 31 kg | 28.5 kg |
| Temp Coefficient | -0.28%/°C | -0.29%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 15 years | 15 years |
| Performance Warranty | 30 years | 30 years |
| Degradation (Year 1) | 1% | 1% |
| Annual Degradation | 0.4% | 0.4% |
| Country | China | China |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: JA Solar JAM78S30 590WThe JA Solar JAM78S30 590W achieves 22.6% efficiency versus 22.1% — a 0.5 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.3 kW more total system capacity, or 2 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: JA Solar JAM78S30 590WThe JA Solar JAM78S30 590W has a better temperature coefficient of -0.28%/°C versus -0.29%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.4% of rated power versus 94.2%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: TieBoth panels offer identical 15-year product warranties and 0.4% annual degradation. Neither has a durability advantage.
4. Power Output
Winner: JA Solar JAM78S30 590WThe JA Solar JAM78S30 590W delivers 590W versus 580W per panel — 10W more. For an 8 kW system, you need 14 panels with the higher-wattage option versus 14 panels, saving 0 panels and the associated racking and labor costs.
5. Cell Technology
Winner: TieThe JA Solar JAM78S30 590W 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. The Canadian Solar TOPBiHiKu7 580W uses TOPCon N-type Bifacial: 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. Both are equivalent-generation technologies.
JA Solar JAM78S30 590W
JA Solar's JAM78S30 is a high-wattage N-type TOPCon module achieving 22.6% efficiency for large-scale installations.
Pros
- + Very high 590W output
- + Excellent efficiency
- + Low temperature coefficient
- + Bifacial design
Cons
- - Very large and heavy
- - Requires heavy-duty mounting
- - Not for small roofs
Canadian Solar TOPBiHiKu7 580W
Canadian Solar's TOPBiHiKu7 combines N-type TOPCon and bifacial technology for 580W output with excellent rear-side energy gain.
Pros
- + Bifacial design
- + Strong N-type efficiency
- + Good for ground mounts
- + Bankable manufacturer
Cons
- - Requires elevated mounting for bifacial gain
- - Heavy panel
- - Higher cost than PERC
Choose JA Solar JAM78S30 590W 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
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Large commercial or ground-mount systems requiring maximum output.
Choose Canadian Solar TOPBiHiKu7 580W If...
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Ground-mount installations that can benefit from bifacial energy production.
Our Recommendation
Both the JA Solar JAM78S30 590W and Canadian Solar TOPBiHiKu7 580W are excellent solar panel options, and the margin between them is narrow. The JA Solar JAM78S30 590W 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 JAM78S30 590W or Canadian Solar TOPBiHiKu7 580W?
The JA Solar JAM78S30 590W wins this comparison by a narrow margin. It leads in efficiency (22.6% vs 22.1%) and matches or exceeds on warranty (15 vs 15 years). For most residential installations, the JA Solar JAM78S30 590W is the stronger choice.
Which panel is more efficient, JA Solar JAM78S30 590W or Canadian Solar TOPBiHiKu7 580W?
The JA Solar JAM78S30 590W at 22.6% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.5 percentage points translates to approximately 10W per panel under standard test conditions.
Which has a better warranty, JA Solar JAM78S30 590W or Canadian Solar TOPBiHiKu7 580W?
The JA Solar JAM78S30 590W comes with a 15-year product warranty and 30-year performance guarantee. The Canadian Solar TOPBiHiKu7 580W offers 15-year product and 30-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The JA Solar JAM78S30 590W has a temperature coefficient of -0.28%/°C and the Canadian Solar TOPBiHiKu7 580W is -0.29%/°C. JA Solar JAM78S30 590W 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 JAM78S30 590W vs Canadian Solar TOPBiHiKu7 580W panels do I need for an 8 kW system?
For an 8 kW system: you need 14 JA Solar JAM78S30 590W panels (590W each) or 14 Canadian Solar TOPBiHiKu7 580W panels (580W each). The JA Solar JAM78S30 590W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026