The purchase of a solar panel system for your home is an investment in energy production. Warranties help to ensure that your investment is a sound one. Your solar electric system produces energy to offset what you would have paid your utility company for that same energy. Losses in energy production due to equipment failures or degraded performance reduce the return on your investment. There are three kinds of warranties relevant to your solar system: product warranties, production warranties and installation warranties.
The product warranties guarantee the physical integrity of the modules and other system components. For example, if one of your modules has a soldered connection fail causing it to stop producing energy, it would be replaced under the product warranty.
Inverters, which convert the electricity from DC to AC, have product warranties from 10 to 25 years. String inverters may need to be replaced after 10 to 15 years. Some manufacturers offer the option of purchasing extended warranties for your inverters.
Most solar modules have a 10-year product warranty. Some high-end modules feature product warranties of 25 years or more.
The energy production warranty generally guarantees that a functioning module will produce at least 80% of its originally rated capacity for 25 years. While the details vary from manufacturer to manufacturer, this type of warranty provides you some assurance that your system will continue to produce power over its lifetime. In practice, identifying whether your system is experiencing a drop in performance that violates this warranty is difficult without the troubleshooting help of an installer. Despite that, production warranties are still a proxy for the expected performance degradation for your solar modules over time. Most solar modules have a 25-year energy production warranty. Some high-end modules feature warranties of 30 years.
This warranty covers the workmanship of the installer and includes such things as the roof penetrations they make to attach your system to the building and the electrical wiring work. The length of installation warranties will vary from installer to installer but generally range from three to 10 years. Some installers will offer warranties as long as 20 years.
Warranties for products, production, and installation have lengthened as solar products and practices have improved. This should give you piece of mind that the investment in solar is a smart one.