How long do solar panels actually last?

Updated

Solar panels offer homeowners a great way to reduce their carbon footprint. Luckily, the lifespan of solar panels will allow you to produce energy for many years, providing a great return on investment.

You can count on most photovoltaic solar panels to last 25 years before they begin to noticeably degrade. Most solar panel companies will provide a standard 25-year warranty for the expected life expectancy of the solar panels. After 25 years, your solar panels won’t necessarily need to be replaced; however, their ability to absorb sunlight will be reduced.

In this blog, we’ll explain how long solar panels last, review solar panel degradation rates, and ways to make sure your solar panels last as long as possible. 

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    What is 'solar panel degradation rate'?

    Over time, solar panels lose their ability to absorb sunlight and convert it into solar energy due to factors such as hotter weather and the natural reduction in chemical potency within the panel. This is what is referred to as the “degradation rate”. 

    The lower the degradation rate, the better the panel. When a solar panel has a lower degradation rate, it will produce more energy over its lifetime.

    Degradation rates vary from one brand to another; higher-quality panels have a lower degradation rate versus lower-quality panels. This is important to keep in mind when doing a solar panel comparison since it might make more sense in the long run to spend more money on higher quality panels. 

    According to a National Renewable Energy Laboratory (NREL) study, premium modern solar panel manufacturers such as Panasonic and LG offer panels with degradation rates as low as 0.30% per year. 

    The worst degradation rate is .80% a year, but as a benchmark, you can expect an average degradation rate of .50% a year for any panel.

    Panel type Degradation rate Reduction over 25 years Amount of original output after 25 years
    Tier 1 0.30% 6.96% 93.04%
    Tier 2 0.50% 11.33% 88.67%
    Tier 3 0.80% 17.53% 82.47%

    For most Tier 1 solar panels, the degradation rate is .30% meaning that each year, the panels performance is reduced by .30%. Over 25 years, that adds up to a total of 6.96% meaning your panels will operate at 93.04% of their original capacity in 2045. 

    If you invest in Tier 2 solar panels, your panels will degrade .50% each year and at the end of a 25-year warranty, they will operate at about 88.67% of their original capacity.

    Unless your solar panels break, have manufacturing defects, or are damaged beyond repair, you can still expect excellent performance from Tier 2 solar panels after 25 years. 

    Do solar panels go bad?

    There is technically no expiration date on solar panels. However, over time, they naturally tend to become less efficient at producing energy. 

    Some panels can also break due to physical damage from extreme weather conditions. For example, when there is extreme cold, reoccurring hail storms or physical damage caused by falling debris, solar panels can develop microcracks that will eventually break the entire panel. 

    Quickly occurring extreme contrasts in temperature can also weaken solar panels because the materials that make them, like solar cells and metals, will contract and expand. Solar panels are also subject to water damage which could occur due to the seal that protects the panels from water degrading. 

    The good news is, a standard 25-year warranty should cover all weather damage to solar panels. Each solar panel manufacturer offers different warranty guarantees, so be sure to read the fine print to make sure your panels are covered under any condition.  

    However, an NREL study has shown that for solar panels replaced since 2000, only about 5 panels out of 10,000 fail annually. 

    When to consider replacing your solar panels

    If after the 25-year period you notice that your energy bill is creeping back up, it might be because your solar energy system is not functioning efficiently. In the event this happens, you might need to invest in new solar panels. 

    Many solar companies offer apps or physical trackers that monitor your solar electricity generation monthly or even daily. Having a grasp of the typical amount of the energy output of your panels will help you notice if something is off. 

    For example, if your solar panels generate 35 kWh of clean electricity per week and you notice that over the years this reduces to 32 kWh, then 30 kWh - and there is no visible debris or increase of shade cover over your roof - this can indicate that your panels are beginning to degrade. 

    When your panels are no longer producing the amount of electricity your home needs, it becomes time to replace them. 

    Find out how much solar panels cost in your area

    What other solar system components might need replacing?

    The hardware that makes up a solar system, including the racking, solar batteries, and inverter, have a higher chance of breaking than the actual solar panels do. 

    Replacing the racking

    Because the racking system is drilled into the roof to hold the panels, it is more exposed to the elements, including sun, rain, snow, and extreme temperatures.

    Replacing the inverter

    You can expect to replace your inverter every 10-15 years. Normally, the solar inverter will need replacing during your solar system’s lifetime because it is working extremely hard as the tool that converts DC electricity into AC electricity for your home to use. 

    Replacing your solar battery

    Solar batteries, like the Tesla Powerwall, are an optional addition to your solar system and are used to store excess solar power. 

    Solar batteries typically have 10-year warranties, which is around the time their performance begins to degrade. So after 10 years, you might need to replace them to maintain peak performance. If you purchase a battery, check with your battery manufacturer for their specific warranty. 

    One way to keep your solar system operating at its peak is to sync up your roof maintenance with solar panel maintenance and replacement. Depending on roof shingle types, a typical roof needs to be replaced about every 25 years, which is the perfect time to potentially replace your solar panels.

    Can you extend the lifespan of a solar panel?

    Solar panels are generally pretty easy to maintain because they are built to withstand weather events like snow, hail and wind. Because solar panels do not require moving parts, they also have a less likely chance of “breaking down” or needing to be repaired. 

    Even though solar panels can be fine if you just leave them alone, you can extend their lifetime by routine care and quality maintenance. To maintain and extend the life of your PV system, you can follow these simple steps:

    • Work with a reputable solar installer that provides routine maintenance checks. Maintenance checks can alert you to any quality degradation in the panels, any issues with the racking attached to the roof and whether or not the inverter is hooked up property. Assuring that the system is working smoothly will help solar panels function at their best.
    • Keep your panels clean by washing them with water if they are dirty. If left on the panel for too long, dust or sand can cause microcracks and scratches on the solar panel. If left unchecked, these cracks can multiply and break the panel. 
    • Remove any debris like fallen tree branches and snow loads. Fallen branches or hail can cause even more damage than dust or sand because they put more pressure on the panel. Falling branches can break panels outright, but small branches left on panels can also cause scratches and apply a lot of weight to panels if they pile up.
    • If snow is left on the panels, it can freeze and cause the panels to get microcracks from extreme cold. It is best to remove any and all debris from panels to remove excess pressure and reduce the likelihood of microcracks. 

    Following these steps will reduce any strain on the solar panels, making them work less hard, to ensure that your panels last as many years as possible. 

    Maintenance will also alert you to any early issues that can be covered in your warranty. If you notice anything off about your solar panels, make sure you contact your provider to get the replacement parts necessary to keep your system running with ease. By keeping your solar panels clean, it'll help them last longer and absorb more sun. 

    Should you replace your solar panels after 25 years?

    Solar panel systems will keep producing electricity even after the 25-year warranty period if they are well maintained. However, it is important to note that they won’t be as efficient at energy production versus when they were first installed. 

    So, you do not need to replace your panels if:

    • Your solar panels produce enough energy for your electricity needs
    • If none of your panels are broken

    But you do need to replace your panels if:

    • Your solar panels produce too little electricity to the point where they no longer adequately power your home
    • Your system was not properly maintained and has many broken panels

    Working with a reputable installer will go a long way in making sure that your solar panels are high quality and will be covered under a warranty. Ultimately, it is rare for solar panels to “go bad,” and you should have no issue relying on your solar panels for 25+ years. 

    How much can you save with solar?

    Key Takeaways 

    • Most solar panels last 25+ years with an average annual degradation rate of .50%.
    • Solar panels do not “go bad” and very rarely are they faulty or break.
    • Solar inverters and solar batteries will need replacing within the 25+ year solar panel lifespan.
    • Properly maintaining your solar panels will help ensure they last longer.
     - Author of Solar Reviews

    Andrew Sendy

    Home Solar Journalist

    Andy is deeply concerned about climate change but is also concerned about cost of living pressures on American families. He advocates for solar energy and solar battery storage only to the extent that they make financial sense for homeowners. He is not affiliated with any particular solar company in the United States.

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