Solar panel warranties typically last 25 years. But when a panel warranty expires at 25 years, the panel doesn’t stop working. It doesn’t suddenly become useless. The warranty ends, but the solar panel’s life goes on.

This guide covers what really happens to solar panels after 25 years of service: degradation rates, why panels still produce power long after the warranty, what your options are when a panel ages, and where solar panel recycling fits into the bigger picture.

Do Solar Panels Stop Working After 25 Years?

No. A 25-year warranty is a manufacturer guarantee, not an expiration date. It says the company will replace or repair panels that fail within 25 years. It doesn’t mean the panels self-destruct on year 26.

Real-world data from installations from the 1980s and 1990s shows that panels still produce electricity after 30, 40, and even 50 years. The oldest functioning solar panels are now over 60 years old. What changes is output. Solar panels degrade at roughly 0.5 to 0.8 percent per year, meaning after 25 years a panel is producing about 80 to 87 percent of its original output.

Solar Panel Output After 25 Years

A 300-watt panel degrading at 0.5 percent yearly produces about 254 watts after 25 years. In a 25-panel residential system (7.5 kW initially), you’d have a 6.4 kW system after 25 years. You’ll pay about 13 to 20 percent more on electricity bills than when the system was new, but the system still offsets most of your electricity use.

Factors That Affect Long-Term Degradation

Panel quality matters. Monocrystalline panels degrade slower than polycrystalline. Climate plays a role: hot, dry climates with relentless UV exposure and coastal areas with salt spray accelerate degradation. Installation quality also affects longevity. Panels with proper ventilation (air gap behind panels) degrade slower. Inverters age faster than panels and typically need replacement around year 12 to 15.

Real Examples of Panels Still Operating After 25 Years

The Smithsonian’s rooftop in Washington, D.C. has solar panels installed in 1975. They’re still generating power, at 50 to 60 percent of original capacity. A California utility installed panels in 1985 and monitored them for 30 years: average output was 78 percent of the initial rating, with none having failed completely.

What Happens When Your Warranty Expires

When your 25-year warranty ends, your panels are still yours and still generating power. If a panel fails after 25 years, you can replace it: parts plus labor typically cost $400 to $600 per panel, cheaper than it was 25 years ago because panel prices have dropped 90 percent.

Some homeowners upgrade the entire system at 25 years. New panels are more efficient, take up less space, and include improved technology. If your old system had 25 panels, a new system might have 18 newer panels producing the same power. Others keep the aging system running until panels fail one by one, then replace failures as needed.

Solar Panel Long-Term Output Calculator

Estimate Your Panel’s Long-Term Output

Solar Panel Recycling Programs and End of Life

When panels do reach end of life (typically 30 to 40+ years), recycling is the responsible path. Modern solar panel recycling separates glass (70 to 80% of a panel by weight), silicon (15 to 20%), aluminum frames, and metal contacts. Modern recycling recovers 95%+ of materials by weight. The Solar Energy Industries Association (SEIA) maintains a recycling directory. Costs for recycling a panel typically range from $20 to $50 per panel.

Case Study: A 28-Year-Old Solar Array Still in Service

Background

A homeowner in Sacramento, California installed a 3.6 kW solar array in 1996 as part of a state pilot program. The system consisted of 24 monocrystalline panels rated at 150 watts each. The homeowner continued monitoring and operating the system through 2024.

Results After 28 Years

In 2024, the system was still producing electricity and passing annual inspection. Output testing showed average panel output of approximately 128 watts per panel, representing about 85 percent of original rated capacity (0.54% annual degradation). The system was generating roughly 5,000 kWh annually, down from an initial 6,200 kWh. The homeowner’s inverter was replaced in 2011 (year 15) at a cost of $2,200. No panels had needed replacement in 28 years.

Decision at 28 Years

The homeowner was considering a system upgrade, not because the old system failed, but because replacing the 24 older panels with 18 modern 400-watt panels would increase output from 5,000 kWh to approximately 8,500 kWh annually, covering their increased electricity needs after adding an EV charger. The old panels will be recycled through California’s e-waste program.

Expert Insights From Our Solar Panel Installers

One of our senior solar panel installers with over 19 years of experience shared their perspective: “The 25-year warranty has become a psychological barrier for some homeowners. They think of solar panels like appliances with a set lifespan. But solar panels are much more like a quality roof or a foundation. They degrade slowly and predictably. The thing that actually fails first is usually the inverter, not the panels. I’ve walked through houses with 20-year-old systems that are running just fine. The panels look a bit faded but they’re still making power. My honest advice: plan for a system refresh around year 20 to 25 if you want peak performance, but don’t expect your panels to die on their 25th birthday. They won’t.”

Do solar panels still work after 25 years?

Yes. Solar panels continue to generate electricity well beyond 25 years. The warranty expiration doesn’t mean the panels stop working. After 25 years of operation at standard 0.5% annual degradation, panels typically produce 80 to 87 percent of their original rated output. Many panels from the 1980s and 1990s are still operational today.

How much output do solar panels lose after 25 years?

At the industry-standard 0.5% annual degradation rate, panels lose about 13 percent of output over 25 years. Premium panels from top manufacturers may retain 87 to 92 percent of original output. Budget panels with 0.8% annual degradation retain about 82 percent. Use the calculator above to estimate output for your specific panels.

Should I replace my solar panels at 25 years?

Not necessarily. If your panels are still producing meaningful power and your electricity needs are met, continuing to operate them is financially sensible. Consider upgrading if your output has dropped significantly, you need more power (EV charging, heat pumps), or you want to take advantage of much higher efficiency available in modern panels.

What happens to old solar panels?

Old solar panels can be recycled through certified e-waste programs or solar panel recycling facilities. Recycling recovers glass, silicon, aluminum, and metal contacts. Some states have mandatory solar recycling programs. Contact the SEIA or your panel manufacturer for recycling resources. Avoid landfilling, especially thin-film panels that may contain regulated materials.

Summing Up

The 25-year warranty is a floor, not a ceiling. Solar panels continue to generate electricity for decades beyond their warranty period, gradually losing a small fraction of output each year through a well-understood process called degradation. After 25 years, most panels produce 80 to 87 percent of their original capacity. After 40 years, expect 70 to 75 percent.

Your options at the 25-year mark are to keep running the system as-is (it still works and saves money), replace failed components individually, or upgrade to a new system for a bump back to 100 percent output and improved efficiency. Whichever path you choose, recycling your old panels through a certified facility keeps valuable materials out of landfills.

For a professional assessment of your aging solar system or a quote for a system upgrade, call us free on (855) 427-0058 or get a free quote here.