Solar 101
The Facts of Light: How Long Do Solar Panels Last?
Most solar panels last 25 years or more with very little maintenance. Learn about degradation, inverter life, warranties and what happens when you sell.
Most solar panels last 25 years or more with very little maintenance. Learn about degradation, inverter life, warranties and what happens when you sell.
"The Facts of Light" is our series answering the questions we hear most about solar. This one is a favourite: how long do solar panels last? The short answer is a long time, and longer than most things we own.
We live in a throwaway society. Phones and laptops, remarkably sophisticated pieces of equipment, are often replaced after a few years. Even cars usually need regular repairs after ten years. Solar panels are different. A panel has no digital processor, no pumps, no fans and no spinning parts. It sits in one place and absorbs sunlight, which is exactly the job it was built for.
A typical panel consists of silicon solar cells protected by tempered glass and an aluminum frame. With so few components that can wear out, panels need very little maintenance beyond occasional inspection.
Early solar installations from decades ago are still producing electricity. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) has published studies on how solar panels perform over time, and found that panels degrade slowly, and that newer technology tends to hold up even better. You can read more in the NREL photovoltaics research pages. Most manufacturers warrant their panels for 25 years, which is a good guide to the expected useful life, and many panels keep running after that.
Full disclosure: panels will not produce quite as much on day 10,000 as they did on day one. This is called degradation. Industry studies commonly put the average rate at roughly half a percent per year, caused by long-term exposure to moisture, heat cycling and sunlight. Over 30 years that adds up to a modest decline, with panels still producing a large majority of their original output. Few products can say the same after three decades outdoors.
Your system also contains an inverter, which converts the DC electricity from the panels into AC electricity your home can use. Inverters have more electronics than panels, so they are the component most likely to need replacement during the system's life, typically once, sometimes after 10 to 15 years or longer depending on the model. We install SolarEdge inverters, which include built-in monitoring so you can see how the system is performing.
Because panels may well outlast your time in a home, it matters that warranties are clear. Manufacturer warranties generally attach to the equipment, which can help when you sell, but terms differ, so confirm the details. At Terawatt Solar, our panels carry a 25-year warranty and our installation work is backed by an 8-year workmanship warranty.
Most durable things are resilient because they are simple and made from quality materials. Crystalline silicon covered by glass is exactly that. It is the same basic technology used on spacecraft, partly because there is no practical alternative in orbit, and partly because it endures harsh conditions. On an Ontario roof, panels are tested to handle wind, snow load and temperature swings.
To see how this applies to your home, explore our residential solar service or request a free site assessment.
Most panels are designed and warrantied to produce for 25 years or more, and many keep producing well beyond that, gradually losing a small amount of output each year.
String inverters commonly need replacement once during the life of the system, often after 10 to 15 years. Check the warranty on your specific model.
Manufacturer product and performance warranties typically stay with the system, but terms vary, so confirm the details in your agreement before you sell.
