First Solar Panel Review: Pros, Cons & Performance
Last updated: February 1, 2026
First Solar solar panel review for 2026. Efficiency, warranty, real-world performance, and whether First Solar panels are worth the investment.
Your installer quoted First Solar panels and you want to know if they're any good. Or maybe you've been comparing spec sheets late at night and First Solar keeps showing up. Either way, you need an honest assessment — not marketing copy. Here's what the data actually says about First Solar's performance, durability, and value.
First Solar manufactures 2 solar panel models using CdTe (Cadmium Telluride) cell technology. Their flagship Series 7 545W achieves 19.8% efficiency at 545W, backed by a 10-year product warranty and 30-year performance guarantee. Panels are manufactured in United States. With an average temperature coefficient of -0.28%/°C and annual degradation rates between 0.5% and 0.5%, here's what you need to know before buying First Solar panels.
Key Takeaways
- • First Solar offers 2 models using CdTe (Cadmium Telluride) technology
- • Top efficiency: 19.8% (Series 7 545W)
- • Product warranty: up to 10 years; performance warranty: up to 30 years
- • Annual degradation: 0.5%–0.5% (lower is better; industry avg ~0.5%)
- • Temperature coefficient: avg -0.28%/°C (excellent for hot climates)
- • Manufactured in United States
First Solar Solar Panel Models
| Model | Power | Efficiency | Cell Type | Warranty | Degradation |
|---|---|---|---|---|---|
| Series 7 545W | 545W | 19.8% | CdTe (Cadmium Telluride) | 10/30 yr | 0.5%/yr |
| Series 6 Plus 465W | 465W | 19.2% | CdTe (Cadmium Telluride) | 10/30 yr | 0.5%/yr |
Sorted by efficiency. Click any model for full specifications.
Performance Summary
Frequently Asked Questions
Are First Solar solar panels good quality?
First Solar panels range from 19.2% to 19.8% efficiency, delivering competitive performance for their price segment. Their 10-year product warranty and 0.5% annual degradation rate on their best models indicate confidence in long-term reliability. First Solar is a focused manufacturer with a targeted product lineup.
How long do First Solar solar panels last?
First Solar panels carry performance warranties of up to 30 years, guaranteeing approximately 84.0% output at warranty end. Most solar panels continue producing useful energy for 30–40 years. With 0.5% annual degradation, the best First Solar models will retain strong output well beyond their warranty period.
Which First Solar solar panel is the best?
The Series 7 545W is First Solar's top performer at 19.8% efficiency and 545W output. It uses CdTe (Cadmium Telluride) cells with a -0.28%/°C temperature coefficient. Best for: Utility-scale projects valuing US manufacturing and hot-climate performance.
Do First Solar panels work well in hot weather?
With an average temperature coefficient of -0.28%/°C across their lineup, First Solar panels perform excellently in heat, losing less power per degree than most competitors. For every degree above 25°C (77°F), expect approximately 0.28% power reduction.
Where are First Solar panels manufactured?
First Solar solar panels are manufactured in United States. US-manufactured panels may qualify for additional domestic content incentives under the Inflation Reduction Act.
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Last updated: February 2026