How Long Do Solar Panels Last? (7).jpg

In most cases, solar panels are warrantied to last 25 years. However, they typically last a lot longer than that. There are first-generation solar panels still in service after 40 years that continue to produce 75% of their original output. Additionally, solar panels are reliable. It is unlikely that they will need to be repaired or replaced before their 25-year warranty is up.

Solar panels last, but do lose some efficiency with time.

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 does solar panel longevity affect the ROI of going solar?

If your solar panels last longer than they are warrantied for, that boosts your ROI. Online calculators often use the common 25-year warranty period that solar panels come with as the basis for how long your system will last, and therefore, as a basis for how long you will own it and earn ROI. But if your panels last for longer than 25 years, all that extra time means extra time that you are earning ROI on your investment in solar energy. The best way to make sure you get maximum ROI on your system is to properly maintain the system. Thankfully, there’s not much you need to do.

How to maintain your solar panel system so it lasts.

All you need to do to maintain maximum output from your solar panel 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.

Inverters are another story. They are often warrantied for 10 years. If you aren’t an Expert Solar Advisors customer, you’ll want to monitor your system for signs of trouble as your inverter ages. If you are an Expert Solar Advisors customer, you don’t need to monitor your system — our team will do it for you. The guarantee with our team is different. We guarantee your system’s power output for 25 years. If anything breaks, we notify you and fix it at our cost.

Expert Solar Advisors’ 25-year production guarantee means worry-free power!

Expert Solar Advisors guarantees more than just that your solar panels will last for 25 years. We guarantee that they will produce a certain amount of power for 25 years, which is based on the terms and conditions of your agreement. If your solar panel system ever stops producing power, or it produces less power than our agreement promises, we will fix the problem and reimburse you for any energy savings that you lost. We monitor your system for you. Expert Solar Advisors is the only solar power company that guarantees the amount of power their systems produce for 25 years.* Go solar with confidence.


Dirk Jordan and Sarah Kurz. (2019) Photovoltaic Degradation Rates – An Analytical Review National Renewable Energy Labs.

* This is based on the terms and conditions of your agreement

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