LONGi vs Panasonic Solar Panels
A side-by-side 2026 comparison of efficiency, price per watt, warranty, and hot-weather performance for LONGi (Mid-Range, 4.3/5) and Panasonic (Premium, 4.5/5).
LONGi (Mid-Range, 4.3/5) and Panasonic (Premium, 4.5/5) are both proven residential solar panels. LONGi is the more efficient panel, while LONGi costs less per watt.
- Most efficient: LONGi, up to 22.8% (vs 22.2%).
- Lower price per watt: LONGi, from $0.42/W.
- Longer product warranty: Panasonic, 25 years.
- Better in hot climates: tie on temperature performance.
- Best for: LONGi on small or shaded roofs; LONGi on a tight budget.
How do LONGi and Panasonic compare on specs?
The table below puts every key 2026 metric side by side and marks the winner on each row. LONGi leads on efficiency; LONGi leads on price.
| Specification | LONGi | Panasonic |
|---|---|---|
| Tier | Mid-Range | Premium |
| Overall rating | 4.3/5 | 4.5/5✓ |
| Max efficiencyHigher is better | 22.8%✓ | 22.2% |
| Max wattageHigher is better | 580 W✓ | 410 W |
| Price per wattLower is better | $0.42–$0.85✓ | $0.95–$1.55 |
| Product warrantyLonger is better | 15 yr | 25 yr✓ |
| Temperature coefficientCloser to 0 is better | -0.26%/°C | -0.26%/°C |
| Annual degradationLower is better | 0.35% | 0.25%✓ |
| Country | China | Japan |
| Founded | 2000 | 1918 |
| Models available | 4 | 3 |
Which is more efficient, LONGi or Panasonic?
LONGi is more efficient, converting up to 22.8% of sunlight into electricity versus 22.2% for Panasonic. Higher efficiency produces more watts per square foot, so it matters most on small or partially shaded roofs. On a large, unshaded roof the difference is minor — you can add a panel or two to match output.
Which is cheaper, LONGi or Panasonic?
LONGi is the lower-cost option, starting near $0.42 per watt before installation. LONGi ranges $0.42–$0.85/W and Panasonic ranges $0.95–$1.55/W. On a typical 6 kW system that price gap works out to a few hundred to a few thousand dollars before incentives like the 30% federal tax credit.
Which performs better in hot weather?
Both panels have similar temperature coefficients, so they lose output at about the same rate in heat. In hot-sun states like Arizona, Texas, and Florida, a better temperature coefficient can mean a few extra percent of summer production.
Which LONGi or Panasonic panel should you choose?
- Small or shaded roof: LONGi — higher efficiency fits more power in less space.
- Tight budget / large roof: LONGi — lower price per watt wins when space isn't the constraint.
- Hot climate: either brand — better heat performance protects summer output.
- Longest protection: Panasonic — 25-year product warranty.
LONGi
Full review →Pros
- World leader in monocrystalline silicon technology
- Vertically integrated supply chain ensures quality control
- Hi-MO series offers excellent power output and efficiency
- Massive R&D investment drives continuous innovation
Cons
- Primarily focused on large-format commercial/utility modules
- US residential presence still growing compared to established brands
- Some geopolitical supply chain concerns
Panasonic
Full review →Pros
- Exceptional temperature coefficient for hot climates
- HJT cell technology delivers superior real-world performance
- Trusted global brand with decades of manufacturing experience
- Strong warranty coverage and reliability track record
Cons
- Premium pricing compared to many Chinese manufacturers
- Smaller product lineup than some competitors
- Panel availability can fluctuate in certain markets
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Get Free Solar QuotesLONGi vs Panasonic FAQ
LONGi is more efficient (up to 22.8% vs 22.2%), and LONGi costs less per watt (from $0.42/W). LONGi holds a 4.3/5 rating versus 4.5/5 for Panasonic. The better panel depends on whether you prioritize efficiency, price, or warranty.
LONGi is the lower-cost option, starting around $0.42 per watt. LONGi ranges $0.42–$0.85/W and Panasonic ranges $0.95–$1.55/W before installation.
LONGi reaches the higher efficiency at 22.8%, compared with 22.2% for the other. Higher efficiency lets you fit more power on a smaller roof.
Panasonic offers the longer product warranty at 25 years. Lower annual degradation also matters: LONGi degrades about 0.35% per year and Panasonic about 0.25%.
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