How long will solar panels on a home last? The panels are not the only component involved in a home solar system and there are a few factors that affect the life of the components. The longevity of other components and the quality of the installation also needs to be considered.
1. Solar Panels made today maintain at least 80% of their original power output or even higher for 20-25 years. Solar panels manufactured in the 1970’s are still working today but not at their original output levels as there is an annual degree of degradation. Panels are getting more efficient over time, allowing more power over less space and currently minimizing degradation to 0.5% annually in the best panels.
2. The Inverter turns the DC electricity from the solar panels into AC electricity used by everyone connected to a utility company. Central Inverters (1 used for the whole system), are warrantied from 10-15 years though you can purchase extended warranties up to 20 years. In the field, good central inverters do last 15-20 years before needing replacing. Micro Inverters (1 attached to each panel), are warrantied for 25 years from the get go. Micro inverters have not been around for 25 years, but to date, they have been performing very well and brought streamlined installing, panel level monitoring and lower voltage to solar installations. One inverter manufacturer combines its central inverter with a voltage regulator for each panel. This produces similar results as a micro inverter system though some argue it creates more possible failure points. It also comes with a 25 year warranty.
3. The Roof Support System, Wiring & Electric Components are not easily visible once installed but must all be rated for use with solar power. There are many quality manufacturers of all these components and all perform for the full life of the system when installed properly.
4. The Quality of Work Done by your installation crew is probably the most important piece. They must know and perform best practices for roofing and electrical work. Their work must comply with current national and state codes. Your local building department must pass the design before a permit can be issued and then inspect the finished project before you can use it. Your utility company will also have its own version of what must be inspected and/or approved. This process, while time consuming, goes a long way towards protecting the consumer and having a solar system ready to work properly for 20+ years. A quality solar vendor also adds on workmanship warranties of 10 years or more in addition to manufacturer’s warranties.
So it can be safely said, no matter which technology options you choose, you can expect a good 20 years out of your solar power system. They are practically maintenance free and you will never need an energy delivery. Now that panel level monitoring is available to the consumer and the installer, finding and solving any issues can be done quickly. I always loved turning on a solar power system for my clients. When people actually see their utility meter going backwards, it starts to sink in and smiles start to grow.