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How Long Do Solar Panels Last?

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Author Image Written by Tamara Jude + 1 other Reviewer Icon Reviewed by Sarah Wilder Updated 03/25/2024

Solar panels can last decades when well-maintained, but like any fixture or appliance, they degrade over time. Most solar panels come with a warranty of 25–30 years, though they can continue working for longer. Our guide explains the factors that impact solar panels’ life span and provides tips for helping them last longer.

What Is the Life Span of Solar Panels?

High-quality solar panels can theoretically last up to 50 years, but most manufacturers warranty them for 25–30 years. That doesn’t mean your panels will stop working once they hit the 25-year mark, but they will drop in efficiency and energy production.

Solar panel efficiency indicates how effectively your panels convert the sunlight they absorb into energy. Over time, that efficiency declines and affects your energy production. This gradual decline in performance is called the degradation rate.

While properly cared for panels can last up to 50 years, the accepted industry estimation of how long solar panels last is 25–30 years. The U.S. Department of Energy cites an estimated operational lifespan of 30–35 years for solar panels but notes that some may last much longer.

What Is Solar Panel Degradation Rate?

The solar panel degradation rate measures how much your solar panels’ power output diminishes over time. The National Renewable Energy Laboratory (NREL) has been tracking degradation rates for the last several years as part of its Photovoltaic (PV) Lifetime Project.

NREL’s findings indicate that solar panels have an average degradation rate of 0.5% per year. So if your solar panels have been operational for five years, your power generation will be 2.5% lower than your initial output. If we apply this to 20-year-old panels, production drops to 90% of the original output. 

Some solar panel manufacturers include a power guarantee or warranty to back their panels’ output. This means your panels are guaranteed to perform at the rate outlined in your contract, or the manufacturer will replace or upgrade them. These policies vary among solar providers but may guarantee power production up to 90% or higher. For example, SunPower includes a power production guarantee of 92% after 25 years.

Which Solar Panels Have the Longest Life Span?

Your solar panels’ quality has a big impact on how long they last. Bloomberg New Energy Finance Corporation (BNEF) developed a tiered rating system to grade solar panel quality. Panels are divided into Tier One, Tier Two, and Tier Three.

Tier One panels are produced by manufacturers with at least five years of experience, stable finances, and a solid brand reputation within the solar industry. These panels offer the highest power production, efficiency, and return on investment. They’re also the most expensive panel options. BNEF does not provide detailed criteria for Tier Two and Tier Three panels.

Among these Tier One solar panels, monocrystalline (mono) and polycrystalline (poly) are the most popular types of solar panels for home installations. Monocrystalline panels offer the best efficiency and power production, and they typically have a lower degradation rate.

For more information about choosing the right solar panels for your home, check out this video with heating expert Richard Trethewey and Mark Trout, Group CEO of Sunworks (formerly Chief Technology Officer of Vivint Solar):

Factors That Affect Solar Panel Life Expectancy

We’ve detailed several factors that can impact not just your panels’ longevity, but your whole system’s efficiency.

Though solar panels work best in sunny conditions, prolonged exposure to extreme heat reduces their efficiency. Extreme heat and cold cycles can cause stresses on the panels and internal components, potentially accelerating degradation. Strong winds or hailstorms can physically damage the panels, while high humidity levels can create a corrosive environment.
Solar panels must be installed correctly in a racking system to keep them in place. Poor installation could cause the panels to slip, crack, or fall from the mounting system. Regular maintenance is also important. Periodic cleaning and inspections can help remove debris and identify any potential issues early on, preventing further damage and extending the panels’ lifespan.
Working with a reputable solar installer is essential to ensuring your panels will last as long as possible. Some installers offer workmanship warranties that cover issues due to faulty installation. If any problems arise, they will repair or replace your panels and fix any faulty mounting systems.
Investing in high-quality solar panels improves your system’s performance and protects against severe degradation. While all solar panels lose efficiency over time, high-quality panels have a lower degradation rate because they’re designed and built better. They use better solar cell technology, more durable materials, and improved designs to generate the best power output.
Manufacturers typically include better warranty coverage with these types of panels. The industry standard is 12–15 years for the manufacturer’s warranty, which protects your system’s components in case of defects. Production warranties, or power production guarantees, are rarely less than 20 years. We recommend looking for companies that offer 25-year warranties to ensure your panels are covered longer.

How Can I Make Solar Panels Last Longer?

Though you can’t prevent panel degradation completely, you can take preventive steps to slow the process. We’ll share a few tips for keeping your panels in the best condition. 

Invest in Reliable Solar Equipment and Installers

Going solar can be expensive, and many homeowners choose cheap solar panels to save money when installing a system. The trade-off is lower power production, which impacts your total energy savings. We recommend investing in high-quality panelsthey’ll be more expensive up-front, but they’ll last longer and produce more savings over time.

We also recommend taking advantage of solar incentives to reduce your solar panel installation costs. These incentives, such as the federal solar tax credit, provide tax breaks and rebates to make going solar more affordable. Incentives are offered at the federal and state levels and through local cities, municipalities, and utility companies. This is an excellent way to invest in better equipment without overspending. California, Massachusetts, and New York currently top the list of states with the best solar incentives.

Along with reliable equipment, you’ll need to find a trusted company to handle your installation. Look for experienced solar companies and installers with positive reviews and a solid reputation. Each solar company will have varying solar panel and battery storage options. We recommend comparing several companies and considering their reputation, pricing, experience, product selection, and customer reviews. 

Keep Up With Routine Maintenance and Servicing

Solar panels require little to no daily maintenance. Rainfall keeps the panels’ surface clean most of the time. However, heavier debris, such as snow or broken tree branches, can sometimes accumulate. This debris will block your panels’ ability to absorb sunlight, so it’s important to clear it off. Many solar panel installers include cleaning in their comprehensive warranty coverage or as a separate service.

Routine solar panel maintenance will help keep your solar panels working efficiently. Visually inspect your panels for any signs of physical damage, cracks, or corrosion on a regular basis. Note that your solar panels aren’t the only component of your solar system. Solar panel systems include numerous parts that keep your system running, such as solar batteries and inverters. These individual parts will also have warranty coverage, but it varies among manufacturers. 

Many solar installers include regular system checks as part of their warranty coverage. In addition, some solar companies provide smart apps that track your system’s performance, health, and energy production. Consider having a qualified technician inspect your system every 2–5 years, depending on your warranty and any specific concerns you might have.

When Should I Replace Solar Panels?

In most cases, solar panels continue to function even as they degrade in efficiency. However, they’ll eventually reach a point when they can’t produce enough power to sustain your home or provide energy savings. Here are a few reasons and situations when you might consider replacing your solar panels:

  • Significant decrease in energy production: If your panels are significantly underperforming compared to their initial output or industry standards for their age, replacement might be necessary. A big change in your energy bill is one warning sign.
  • Reaching the end of their lifespan: As panels approach 25–30 years old, their efficiency will naturally decline, and replacement might become more cost-effective considering the potential decrease in energy savings.
  • Physical damage: Visible cracks, delamination, or other physical damage to the panels can compromise their efficiency and safety. Repairing individual panels might not always be feasible or cost-effective, necessitating replacement.
  • Technological advancements: If your panels are significantly older and newer, more efficient models are available at a reasonable cost, upgrading could be a good long-term investment.
  • App alert or professional recommendation: You may receive alerts about your panel’s health through your solar provider’s dedicated app. An alert could be a sign of panel damage or an issue with the system itself. We recommend reaching out to your solar installer to have your panels tested and possibly replaced if this occurs.

If your solar panels fail while still under warranty, your installer will repair or replace them. However, if panel failure occurs outside your warranty period, you’ll be financially responsible for the replacement. 

Our Conclusion

Investing in solar panels offers many long-term benefits. Though all panels degrade over time, you can extend their life span with routine maintenance and care. You should also consider investing in high-quality solar panels from a reputable company. Taking these steps should ensure your panels last 25 years or longer.

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FAQ About How Long Solar Panels Last

What is the average life span of solar panels?

The average life span of solar panels varies depending on the type of panel and other factors. Most solar panels have a life span of at least 25–35 years, but it’s possible for them to last much longer.

What is the payback period for solar panels?

The payback period for solar panels is the time it takes for the cost savings generated from solar energy production to offset the initial installation cost of the system. The payback period for solar panels typically falls between six and 10 years. The exact length of time varies depending on the system cost, energy consumption, electricity rates, financial incentives, and location.

Do solar panels become less efficient over time?

Yes, all solar panels become less efficient over time. High-quality solar panels typically degrade at a lower rate than cheaper, less efficient models. Loss of efficiency can be accelerated by other factors, including panel damage, extreme weather conditions, and faulty parts or installations. 

What happens to solar panels after 25 years?

After 25 years, solar panels will be less efficient and produce less power. This doesn’t mean your solar panels will stop working, but they may be less effective at powering your home and lowering your energy savings. When panels degrade to the point where they no longer produce power, they’re ready to be recycled.

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