In most cases, solar panels are warrantied to last 25 years. However, they can last a lot longer than that. There are first-generation solar panels still in service after 40 years that still produce 75% of their original output. Additionally, solar panels are reliable, it is unlikely that they’d need to be repaired or replaced before their 25-year warranty was up.
Solar panels vs. Efficiency
Solar panels lose between 0.5% to 1% of their efficiency every year. Because of that rate of loss, at the end of the 25 year warranty period, the panels will still output between 75 to 87.5% of the original amount of power they made when they were new. In fact, a National Renewable Energy Laboratories (NREL) study found that 80% of all solar panels outlast their 25 year warranty period.
That same NREL study also shows that 78% of the systems tested in the study showed less than a 1% degradation rate per year. Are solar panels that still put out 75% or more of their original output still useful? Yes! If your panels are still putting out most of the energy they were originally designed to produce, those panels are still useful.
How to maintain your solar system?
All you need to do to maintain maximum output from your solar system is to occasionally dust off the panels. You should also keep trees trimmed and clear of your system so the shade doesn’t reduce your systems’ power output. Solar panels are very reliable and they don’t need any maintenance beyond keeping them clean.