Solar panel failure rates: Is solar reliable?

A common concern for many homeowners installing solar is their solar panel failure rate. Going solar is a financial investment, and knowing that your panels will continue to work reliably well for many years is important. This article will examine solar panel reliability and possible reasons why a solar panel could perform below expectations.

A 2017 report from the National Renewable Energy Laboratory (NREL) at the U.S. Department of Energy examined 54,500 PV systems installed between 2005 and 2015 to identify the number of "failed panels" or panels needing replacement. NREL found a median failure rate of just 5 out of 10,000 panels annually, which comes out to a 0.05% failure rate on all photovoltaics.

The study also compared solar panel failure rates between 1980 and 2000 to the data above (2000-2015) and found that panels installed between 1980 and 2000 failed at twice the rate of more modern installations. This is further reason to be optimistic about the reliability of your solar panels – not only are failure rates extremely low at 0.05%, but they are improving over time as technology advances and installations become more resilient and high-quality.

This number is an average for all solar installations and does obscure some important insights. Solar panels in harsher climates – hot and humid climates, for example – exhibit higher failure rates, balanced out by panels installed in colder climates. Additionally, some panel manufacturers are known to have produced defective batches of panels, hidden in the numbers by the vast majority of high-quality, reliable solar panels. This is all to say that solar panels are very reliable, but there can be oddball cases, as with any consumer product, where internal or external factors cause unexpected failure.

There are many possible sources of solar panel failure, and researchers and manufacturers are still working to determine how and why panels fail. Here are a few known reasons why your solar panels may need to be replaced.

Weather

In rare cases, extreme weather events can cause panel failure and damage. The likelihood is very low, but intense hail or hurricane-strength winds can potentially cause damage to your solar panels. In addition to wind and hail, panels in hot and humid climates exhibit slightly higher failure rates. These failures are rare and only occur in the most severe types of weather, as strong enough weather events can damage any outdoor technology equipment.

Manufacturing defects

If a faulty production run of solar panels hits the market, those panels are at high risk of failure. Generally, defective solar panels never make it to the market, and high-quality solar companies like LG, SunPower, and Panasonic (among many others) pride themselves on quality panels. Broken/chipped solar cells and scratched glass, among other physical blemishes, are some of the more common defects in solar panels.

To further protect you from failed solar panels, most manufacturers offer solar warranties with their products to safeguard against unforeseeable issues with your solar panels. Solar contracts come in two varieties: performance and equipment guarantees. Performance guarantees aim to ensure your panels are producing power above a certain guaranteed level, while equipment guarantees protect against total failure of PV modules.

The industry standard for equipment guarantees is ten years, but the best solar panels offer up to 25 years of equipment warranty coverage. That coverage will pay for replacing a failed panel for reasons of manufacturing defects or durability issues, essentially covering any way your solar panels might physically fail. So, even in the rare case of a panel failure, odds are your panel manufacturer will be compelled to replace the faulty panel free of charge.

Find quotes for reliable solar panels

If you are considering going solar, it's important to compare all of your options. Using the EnergySage Solar Marketplace, you can solicit quotes from verified installers and compare them. When viewing your quotes, you can see equipment and warranty information and even reach out to installers to understand how they will provide you with a reliable solar system.