How long do solar panels last

April 22, 2019 | 3min read

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 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 last but lose 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 solar panel longevity affects the ROI of going solar

If your 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. 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 system so it lasts

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.

Inverters are another story. They are often warrantied for 10 years. If you aren’t a Freedom Forever customer, you’ll want to monitor your system for signs of trouble as your inverter ages. If you are a Freedom Forever customer, you don’t need to monitor your system, we’ll do it for you. Our guarantee is different. We guarantee your system’s power output for 25 years. If anything breaks, we notify you and fix it.

Freedom Forever’s 25-year production guarantee means worry-free power

Freedom Forever 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 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 you lost. We monitor your system for you. Freedom Forever is the only solar power company that guarantees the amount of power their systems produce for 25 years.*

* Based on the terms and conditions of your agreement

Ready to go solar? Call us at 800-685-1850 or click below to get started.


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

Web 22 Apr 2019