Like every device, solar panel systems degrade over time, which means that they generate a smaller amount of electricity over time, even though the amount of sunlight they receive doesn't change.
How long do solar panels last?
When people talk about solar panels, you'll often hear the number “25 years” tossed around like some magic guarantee. But in reality, the lifespan of a solar panel is much more complicated. Most manufacturers do offer a 25-year performance warranty, meaning your panels are expected to still produce about 80% of their original power after 25 years.
Studies such as those from the National Renewable Energy Laboratory (NREL) show that modern solar panels lose about 0.5% of their output per year on average. That means after 25 years, the panels are still working, just not quite as powerfully as when they were new.
How long does a solar inverter last?
Most people focus on the panels, but the inverter—the device that turns solar electricity into usable power for your home—usually doesn't last as long. Standard string inverters typically last about 10 to 15 years, which means you'll probably need to replace them at least once during your panel system's lifetime.
Several factors impact what affects the lifespan of solar panels, including: Quality of Materials: Panels made with premium photovoltaic cells degrade more slowly. Weather Conditions: Extreme heat, hail, heavy snow, and strong winds can accelerate wear.
To extend the useful life of solar panels and modules, it is crucial to quickly identify any potential hotspots. It may be difficult to visually inspect a large PV plant without assistance. Therefore, an automated approach is needed for solar panel diagnosis. Cleaning panel surfaces reduce soiling.
According to the NREL, the average solar panel loses about 0.5% of its generating power each year. Some panels, especially cheaper or poorly made ones, can degrade even faster—sometimes losing up to 1% per year. Over 20 years, that means you could see a 10% to 20% drop in how much electricity your system produces.