When thinking about going solar, it can be helpful to understand the expected lifespan of your solar panels, and how long they’ll produce enough energy to power your home. This allows you to compare the life of solar panels to the initial upfront cost of installing that solar power system on your roof, and make sure you’re getting a good return on your investment.
The short answer to “How long do solar panels last?” is: You can expect solar panels to power your home for an average of 25 to 30 years. The long answer is a bit more complex, as panels can keep generating electricity well past that timeline, depending on factors such as weather, and how well you service and maintain your solar power system.
In this article, we’re going to look at how long solar panels last, why the expected lifespan of a solar panel is a complex answer, and how you can extend the life of your solar system.
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Can We Accurately Estimate Solar Panel Lifespan?
Since most homeowners are looking for solar pv (photovoltaic) power to help reduce their electricity costs, it makes sense that you want to predict the life of your solar panels. If you can determine the life expectancy of solar panels accurately, you can calculate the long-term value they offer.
The problem with discussing solar panel lifespan is that solar panels don’t just produce the same amount of power for 20 years, and then suddenly stop producing electricity completely. Instead, they slowly degrade over time, producing less and less power as they get older. Homeowners then have to determine when it's worth replacing those older panels with new panels to get back to maximum energy generation.
The industry uses 25 years as the average solar panel lifespan because data shows that’s the amount of time in which most people still receive enough production from their panels to meet their home’s energy consumption needs. So if you’re wondering how long do solar panels last, a safe answer is around 25 years.
Equipment Warranty and Performance Warranty
The average 25-year lifespan of a solar panel aligns with the typical warranty terms that many solar panel manufacturers offer. There are two types of solar panel warranties, and warranty terms can provide you with additional information about the expected life of a solar panel.
The first is an equipment warranty, which guarantees the panel against manufacturing defects. For example, an equipment warranty might guarantee that the panels won’t fail for 10 or 12 years.
The second is a performance warranty, which guarantees that your panels will produce at least a minimum amount of electricity over a specific period of time. For example, a performance warranty might guarantee that your panels will produce at least 90% of their maximum production for the first 10 years, and then at least 80% of their maximum production for the next 15 years, for a total performance warranty period of 25 years.
Higher efficiency panels may also come with a better performance warranty, guaranteeing that they maintain that increased efficiency over time.
Factors That Determine Solar Panel Lifespan
The principal factors that play a role in your expected solar panel lifespan include the equipment you choose, the location you live in, the maintenance you perform, and more.
1. Solar Panel Age
If you already have a solar power system, you might be wondering how much longer your panels can provide optimum service to match your consumption. We recommend that you start with the typical 25-year timeframe and base your calculations around that baseline.
It's important to note that, with regular care and attention, your system can continue serving you well beyond the 25-year mark. However, when your solar panels near their 25th birthday, you should begin to prepare for replacements as the life expectancy of solar panels comes to an end.
Higher-quality panels typically have a longer lifespan, as they lose energy-generating potential at a slower rate. One big advantage of investing in higher-quality solar panels for your initial solar installation is that they can be expected to provide sufficient energy generation for a few additional years.
2. Weather Conditions
Different weather elements have varying effects on your panels, including:
- Wind - While wind rarely has a direct impact on solar panel efficiency, high wind speeds can cause the system to vibrate. If these vibrations continue for an extended period of time and with any frequency, the components holding the panels in place can loosen, which may cause other types of damage over time.
- Rain - If not installed at a steep enough angle, rain can accumulate on the panels and corrode them. Over time, the corrosion will reduce solar panel effectiveness, lowering the amount of electricity they can supply.
- Heat - When exposed to a lot of heat, the seals around your solar panel can become brittle, and may begin letting in water. If there is penetrating moisture, the panels can quickly lose their ability to convert rays from the sun into electricity. Another effect of exposure to high levels of heat is discoloration, which can also negatively affect solar panel efficiency over time.
- Snow - Just like heat, snow can also cause solar panel frames to crack, warp, and otherwise distort from the freezing temperatures. If this happens, you’ll likely experience reduced electricity output from your solar panels.
3. Maintenance and Service History
To retain solar panel efficiency over time, it is essential to perform regular checks and service on your system, as overall maintenance and repair history can impact the expected lifetime of solar panels. Catching any issues early can help extend the life of your solar power system, and is a superb reason to consider investing in regular solar panel monitoring and service.
We recommend that you hire a trusted company like Palmetto to perform any necessary solar panel maintenance. In addition to increasing your solar panel system's life expectancy, regular professional service may be required to keep your warranty intact.
Lastly, Palmetto’s trained solar experts service your equipment with the tools and knowledge needed to get the job done right the first time, which prevents you from having to undertake risky repairs yourself, or potentially damage your system and reduce its expected lifespan.
4. Geography
Your location can influence solar panel effectiveness and longevity of your solar power system. Since weather conditions vary by geography, if you live in an area where summers tend to get very hot or winters tend to get freezing cold, solar panel degradation may occur faster.
For example, in areas that experience a lot of snow and ice, the weight of heavy snowfall can cause the frame to separate from the panel, thus exposing the solar cells and other internal components and shaving a few years off your system's lifespan.
Large temperature changes can also lead to seasonal contraction and expansion, which can cause solar panels to develop microcracks over time that speed up their degradation rate.
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What is Solar Panel Degradation Rate?
When it comes to answering how long do solar panels last on average, it is important to consider solar panel degradation, also known as the solar panel degradation rate. The solar panel degradation rate measures the slow and continuous damage that your panels will experience during their lifespan, due to the factors such as age, weather, and service history.
Solar power system degradation occurs in all panels, regardless of type. As they age, solar panels produce less electricity from the same amount of sunlight. This occurs as the result of a variety of factors, including a panel’s natural reduction in chemical potency over time.
Typically, higher-quality, high efficiency panels have a lower degradation rate, while lower-quality panels have a higher degradation rate. The lower the solar panel degradation rate, the more energy that panel will produce over its lifetime.
Ordinarily, degradation takes away anywhere between 0.3% to 1.0% of a panel’s efficiency annually, depending on the age of your panels. Research by the National Renewable Energy Laboratory (NREL) found that, “solar panels have a median degradation rate of about 0.5% per year.”
For instance, assume that your solar panels have an initial output of 10,000 kWh annually. If they degrade at a rate of 0.4% each year, you can calculate their output at the end of the first year as follows:
- Initial output = 10,000 kWh
- Lost output = 10,000 kWh × 0.004 = 40 kWh
- Remaining output = Initial output − lost output
- Remaining output: 10,000 kWh − 40 kWh = 9,960 KWh after 1 year
Then during the second year, your solar panels lose .4% again, but they have a lower initial output, so you can calculate their output at the end of the second year as follows:
- Initial output = 9,960 kWh
- Lost output = 9,960 kWh × 0.004 = 39.8 kWh
- Remaining output = Initial output – lost output
- Remaining output: 9,960 kWh – 39.8 kWh = 9,920 KWh after 2 years
The math is a little more complicated than just taking your solar panel degradation rate and multiplying it by the number of years, but here’s a general idea of how much production is left after 25 years, based on typical degradation rates:
To be clear, those figures are just an estimate, as your actual degradation rate may increase or decrease over time depending on external factors like weather and your solar panel service plan.
Other Solar Power Components That Wear Out
While your solar panels typically last for 25 years or more, that doesn’t mean your system will be trouble-free for that entire time.
If you are wondering, “Do solar panels wear out?” then keep in mind that other components in your solar power system also wear out and require regular service, maintenance, and replacement, including inverters, wiring, racking, and add-ons like solar battery storage.
1. Solar Inverters
While solar panel inverters may not be as visible as solar panels, they are just as crucial to the entire system’s performance. When solar panels absorb sunlight, they channel the energy to the inverter, which converts the DC current from the panels into AC electricity that your home can actually use.
If your solar panels don’t produce enough electricity to meet your needs, the inverter draws power from the grid to supply that excess energy demand. Moreover, inverters can also feed surplus power from your system to the electricity grid if you’re eligible for net metering.
It’s important to note that your average inverter lasts about 10-12 years, so you’ll likely have to replace it at least once during the average lifespan of solar panels. Thus, it’s crucial to take care of inverters to ensure they are in prime working condition and don’t require more frequent replacement during the life of your system.
For more information about inverters, check out our Solar Inverter Guide.
2. Wiring
As your solar panels absorb sunlight, they rely on a network of wires to transmit the energy to the inverter, which then uses wires to transmit electricity to your home. If there is any damage to any of the wiring, especially between the panel and the inverter, you’ll see less solar energy can be converted into electricity, and the lifespan of your system may be reduced.
3. Physical Supports (Racking)
To remain firmly in position on your roof, solar panels are held in place using various physical supports, called racking. Just like your solar panels, these supports are also exposed to the elements, including snow, rain, and extreme temperatures, so they can weaken with age. If it’s windy, extra pressure is applied to your panel racking, which can result in damage to other components.
4. Solar Batteries
Solar batteries help you make the most of your system's potential, as they can store surplus electricity for later use. However, because of the way that solar batteries store excess electricity, the average solar battery lifespan is around ten years, and they'll need to be replaced sooner than your panels in most cases.
For more information about energy storage, check out our Solar Battery Guide.
How Can I Improve the Life Expectancy of Solar Panels?
While there are many ways your solar panel system can experience reduced efficiency over time, you do have control over that impact. Since most degradation and damage happen slowly over time, adopting good maintenance habits can help you identify and address such issues early, preventing additional damage. The earlier you can account for any loss in panel efficiency, the greater chance you have of preventing long-term concerns.
Your solar panel system may produce reliable amounts of electricity well beyond the 25-year mark with good care, so if you want to enjoy longer-than-average energy generation, you should follow these solar panel care tips:
1. Clean Your Solar Panels
If anything covers the solar panel, it will affect its ability to absorb sunlight, reducing generation capacity. The types of debris you might find on your panels include pollen, bird droppings, leaves, and dust, and depending on the substance, it has the potential to damage the panel glass or other electrical components.
As such, you should thoroughly clean your solar panels every year, and consider cleaning them more frequently if you live in an especially dirty area. This helps with increased efficiency, and maximizes your solar power production capability.
Professional cleaning is recommended, and for more information, check out What Homeowners Should Know About Solar Panel Cleaning.
2. Sign Up for Professional Solar Service
To ensure your solar panels retain their optimal production, you should enlist professionals to monitor your system’s performance, and provide any necessary service if they detect an issue. Trained solar service technicians from trusted solar companies can perform necessary repairs on your existing equipment, or replace the damaged parts if needed, to get you back up and running as quickly as possible.
If you want to rest assured that your system is in safe hands, check out Palmetto Protect. Available to all homeowners with a solar power system, Palmetto Protect offers real-time energy monitoring, fast and reliable support, and comprehensive energy recommendations, with a variety of service levels to match your specific needs.
When To Consider Replacing Solar Panels
If your solar panels are a couple decades old, you might be thinking about replacing them with new panels. One of the easiest ways to tell if it's time to invest in new equipment is to monitor the amount of power your system produces.
If you have access to the Palmetto App, you can view production stats, and compare your current monthly production with historical averages. For example, if your system was generating 500 kWh of clean energy every month when it was first installed, but you've noticed those numbers drop, and now it only produces 400 to 450 kWh per month even when the weather is great, it might be time to consider a replacement.
If you don't have access to the Palmetto App, many inverters also provide a way to view energy production, so you can compare those numbers with historical averages over time.
Another sign that it's time to consider a system upgrade is if you notice that your utility bills are increasing every month. There is some seasonality to solar electricity production, so your utility bills are always going to fluctuate some, but if you notice large increases in the amount you owe the utility company, compared to similar times in previous years, that can indicate your solar panels are degrading and it's time to consider a replacement.
In short: If your solar panels are still producing enough electricity to power your home, and none of the panels are broken or damaged, you don't need to replace your panels. But, if you're drawing a lot of extra power from the grid, or your system hasn't been maintained and some of the equipment is broken, it's probably time to contact a solar installer and talk about an upgrade.
Key Takeaways
If you want to know how long do solar panels last, most solar panels have an average lifespan of 25 years or more, which means the savings you'll enjoy from solar power are undoubtedly worth the investment.
As solar panels age, they don’t necessarily “die” or stop working, they just degrade and produce less energy over time, until eventually they don’t generate enough electricity to power your home.
While solar panels can last for 25+ years, other parts of your solar power system, like inverters or battery storage, have a shorter lifespan, so it’s important to monitor the performance of your entire system and get that equipment serviced and maintained as well.
You can help extend the life of your solar power system with proper service and maintenance. A service like Palmetto Protect is an easy way to have solar experts monitor your system, catch issues before they become larger problems, and get any problems fixed quickly, safely, and professionally.
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Cory O'BrienSenior Director - Growth MarketingCory brings over 8 years of solar expertise to Palmetto, and enjoys sharing that knowledge with others looking to improve their carbon footprint. A dog lover residing in Asheville, NC with his wife, Cory graduated from UCSB. If you run into him, ask him about the company he founded to rate and review beer!
