Installing a solar power system for your home is a significant investment. When deciding whether it’s worthwhile, homeowners often want to know how much power their panels will generate and how long they’ll continue operating efficiently. All solar panels degrade over time, meaning they gradually produce less power than when they were brand new.
While solar degradation is something to consider, it’s not nearly as concerning as many people assume. It was a larger issue in the past, but advancements in technology mean modern solar panels degrade far less than those produced even a decade ago. Let’s examine average degradation rates for different types of solar panels and the factors that influence long-term performance.
Average Solar Degradation Rates
Once solar panels are installed and exposed to sunlight, they experience a small amount of early degradation. This light-induced degradation typically results in panels losing about 1% to 2% of their capacity during the first year. After that initial period, degradation slows and stabilizes at an average rate of 0.25% to 0.8% per year.
Monocrystalline, or N-type, solar panels generally degrade at lower rates—usually no more than 0.25% to 0.5% per year. These panels are also less susceptible to light-induced degradation, often losing only 1% to 1.5% of capacity in the first year. Polycrystalline, or P-type, panels tend to degrade more quickly, though typically no more than 2% in the first year and under 1% per year afterward. Higher degradation rates are one reason P-type panels are becoming less common.
Most manufacturers warranty their solar panels for 20 to 25 years. These warranties usually guarantee that panels will maintain at least 80% of their original capacity throughout the warranty period. Some manufacturers also specify that first-year degradation will not exceed 3%.
For example, a 6-kilowatt solar system that degrades by 1% in the first year and 0.5% annually thereafter would still operate at nearly 90% of its original capacity after 20 years.
Factors That Impact Solar Degradation Rates
Homeowners typically have many options when choosing solar panels, making manufacturer and model selection an important decision. While lower-cost panels can reduce upfront expenses, they often degrade faster and may come with less comprehensive warranties. Premium panels usually maintain higher performance levels over time and generate more power for longer. They also tend to operate more efficiently, producing more electricity per square foot.
Climate is another factor that affects solar panel degradation. A common misconception is that cold climates reduce panel efficiency and lifespan, but the opposite is often true. Cold temperatures generally have little to no negative impact on solar performance, while extreme heat does. High temperatures reduce efficiency, and prolonged exposure to extreme heat or humidity can accelerate degradation.
This means solar panels in Texas may degrade slightly faster than in cooler regions, though not enough to be a major concern. Even in this climate, a properly installed and well-maintained solar system can still operate at more than 80% of its original capacity after 25 years.
Installation quality also plays a role in long-term performance. Improper installation can cause issues such as voltage spikes or current leakage, which increase degradation rates. For this reason, it’s essential to work with an experienced, local solar provider.
At GVEC Solar & Battery Services, we’ve provided expert solar services throughout South Central Texas since 2013. Our experienced team specializes in solar system design and installation and can help you select the ideal setup for your home. We also offer repair and maintenance services to ensure your system continues producing power efficiently for years to come. Contact us today to schedule a consultation or service appointment.
