How Long Do Solar Panels Last?
Residential solar panels are remarkably durable, with systems capable of lasting up to 50 years under the right conditions. However, the industry-standard lifespan for most panels ranges between 25 and 30 years. That said, reaching the 25-year mark does not mean your panels will suddenly stop working.
Instead, it means that their efficiency will have declined gradually over time. Even after 25 years, many solar panels still operate at around 80% of their original energy-producing capacity. In some cases—particularly with higher-quality brands—panels can continue to produce electricity for decades beyond this point, just at a reduced efficiency rate.
Panel Degradation: What to Expect
Panel degradation is the gradual decline in solar panel performance over the years. On average, most solar panels degrade at a rate of about 0.5% to 1% per year. If a panel starts with a 100% production rate, it might still operate at roughly 87.5% of its original capacity after 25 years if the degradation rate is 0.5%.
Several factors influence the degradation rate, including:
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Panel quality – Higher-quality materials and manufacturing lead to slower degradation.
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Local weather – Extreme heat, cold, salt air near the coast, or frequent snow accumulation can speed up wear.
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Installation practices – Poorly installed panels may degrade faster.
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Maintenance – Neglecting routine care can compromise long-term performance.
Choosing a trusted installer is key to maximizing the lifespan of your investment.
Routine Maintenance Matters
Regular maintenance plays a vital role in maximizing your solar system’s long-term efficiency. It’s recommended to clean your solar panels at least once a year, ideally in spring or early summer when pollen and debris tend to accumulate. Even a thin layer of dirt, dust, bird droppings, or leaves can result in up to 7% energy loss.
Professional solar panel cleaning services are equipped to safely and effectively remove buildup without damaging your system.
Beyond cleaning, schedule a professional inspection every three to five years. During an inspection, a certified technician will:
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Evaluate electrical connections
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Check inverter performance
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Inspect roof penetrations
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Ensure structural stability
These routine assessments can identify minor issues—like loose wires or small leaks—before they escalate into major problems.
What Do Warranties Cover?
Understanding your solar panel warranties is crucial. Most systems come with two main types:
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Product Warranty (10–25 years) – Covers manufacturing defects and physical damage unrelated to wear and tear.
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Performance Warranty (usually 25 years) – Guarantees the panel will produce a specific percentage (often around 80%) of its original capacity by the end of the warranty period.
If your system underperforms within the warranty terms, you may be eligible for replacement panels or compensation.
When Should You Replace Panels?
While solar panels can operate well beyond their 25-year life expectancy, replacement may be worth considering if:
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Efficiency drops below your household’s needs
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You’re undertaking a major roof renovation or replacement
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You want to upgrade to newer, more efficient technology
Final Thoughts
Solar panels are a long-term investment designed to deliver reliable performance for decades. By understanding panel lifespan, degradation rates, and warranty coverage, you can make informed decisions that protect your investment. Partnering with experienced professionals ensures your system delivers clean, cost-effective energy year after year.
About Define Solar
Define Solar, serving NJ and PA, specializes in professional solar installations with an unmatched commitment to communication, quality, and detail. With years of experience and a proven track record, the company delivers reliable, world-class service tailored to each client’s needs.
