One of the biggest factors that determines how long solar panels last is the quality of the product. Solar panels available on the market are classified in three tiers: Tier One, Tier Two and Tier Three. Among other criteria defined by the industry, Tier One manufacturers have been producing solar panels for five or more years, have stable finances and are highly regarded for service and quality of their products.

Not only do Tier One manufacturers have higher standards, but their solar panels often have a higher output after 25 years in comparison to Tier Two or Tier Three panels. The degradation rate for Tier One solar panels is 0.30% annually compared to 0.50% for Tier Two and 0.80% for Tier Three. The catch is that Tier One panels generally cost 10% to 30% upfront, however, it’s highly likely that cost will be recouped in time.

According to a study from National Renewable Energy Laboratory (NREL), the average degradation rate is 0.50% across all solar panels. That means you could still expect your solar output to be about 89% of its original output after 25 years.

Factors That Affect the Lifespan of Solar Panels

Some factors that affect solar panels’ lifespans—such as climate and extreme weather events—are beyond your control. Still, there are ways in which you can increase the longevity of your solar panels.

Quality

As the breakdown among solar panel Tiers shows, the quality of your panels makes a significant long-term difference to the output. For an indication of what type of output you can expect, look at the production warranty offered by the manufacturer. Companies that offer 25 or more years are willing to stand by their products for a long time—and that’s a good sign for you.

Installation

By working with an experienced installer to get your solar panels in place, you can feel confident that the racking will support the panels long-term. If improperly installed and wired, your solar panels may degrade faster. Many of the best solar companies also offer maintenance checks to make sure the system is operating properly and to catch any issues before they turn into larger problems.

Maintenance

Besides the savings potential and the environmentally friendly benefits, one of the biggest selling points of solar panels is that they are quite low-maintenance. If you want to extend your solar panels’ lifespan, however, it can help to take care of them. For example, debris that accumulates on solar panels not only blocks access to the sun, but can also cause scratches and chips on the panels that lead them to break. To avoid situations like this, it’s wise to regularly clean off your solar panels or install solar panel critter guards.