A solar system comes with an individual equipment warranty for a certain period of time which includes solar panels, inverter, battery and even installation. Say Solar panels, usually, come with a performance warranty of a maximum of 25 years which covers panels' power output for a certain period of years. For instance, a panel may still produce 90% of its rated output after 10 years and 80% after 25 years, according to a power output warranty given by manufacturer. It may also be stated as a linear warranty in one figure, for example, 85% after 25 years. Additionally, the warranty period for inverters and batteries may vary depending on the manufacturer. The other important warranty that needs to consider is the workmanship warranty by your CEC-approved solar installer.