Solar panels don’t suddenly stop working after 25 years. That number comes from the standard manufacturer warranty period, not a hard expiration date. Most panels are still producing electricity at that point, typically at 80 to 85% of their original capacity. What actually happens at the 25-year mark depends on whether you choose to keep them running, replace them, sell them, or decommission the system entirely.
Why 25 Years Is the Standard Benchmark
The 25-year figure comes from performance warranties, not engineering limits. Most manufacturers guarantee that panels will retain at least 80% of their rated power output after 25 years. Canadian Solar, for example, warrants 84.95% output at year 25. That means a panel originally rated at 400 watts would still produce roughly 320 to 340 watts after a quarter century of daily use.
The degradation is gradual. Panels lose about 0.5 to 0.7% of their output per year on average, so you won’t notice a sharp decline at any single point. Many panels continue operating well beyond 25 years, just at progressively lower output. Some field studies have documented panels still functioning after 30 or even 40 years.
How Panels Physically Break Down
The slow loss of power comes from several physical processes happening inside and on the surface of the panel. The silicon cells themselves develop microcracks over years of thermal cycling, as the panel heats up during the day and cools at night. The encapsulant layer that seals the cells can yellow or delaminate, reducing the amount of light reaching the cells. Electrical connections between cells can corrode, and junction boxes on the back of the panel can fail.
Climate plays a significant role in how fast this happens. Hot, humid environments accelerate delamination and junction box failures. Thin-film panels (less common in residential installations) are particularly vulnerable to glass breakage and corrosion of the light-absorbing layer. Panels in moderate, dry climates tend to age more gracefully and can exceed their warranty performance targets.
The Rest of the System Ages Differently
Your panels are only one part of the system. Inverters, which convert the panels’ DC electricity into usable AC power, have shorter lifespans and will likely need replacement before the panels themselves wear out. Standard string inverters last 10 to 15 years, meaning you’ll probably replace yours at least once during a 25-year panel life. Microinverters, the small units mounted behind each panel, tend to last 20 to 25 years and may not need replacement at all.
Mounting hardware, wiring, and racking are generally durable, but roof-mounted systems create another consideration: your roof. If you need a roof replacement during the panels’ lifetime, you’ll have to remove and reinstall the array, which adds cost.
Keeping Panels Past Their Warranty
If your panels are still producing useful power at 25 years, there’s no requirement to remove them. Many homeowners simply keep them running. The warranty expiration means you’re no longer covered for performance drops, but the panels don’t become unsafe or nonfunctional. You’re just accepting whatever output they deliver.
The decision to keep or replace comes down to math. If newer panels are significantly more efficient, the energy gains from upgrading might justify the cost, especially if your electricity rates have risen. But if your 25-year-old panels still cover most of your electricity needs, the financially sound move is often to leave them in place and only replace the inverter when needed.
What Removal and Disposal Cost
If you do decide to take the system down, expect to pay $200 to $500 per panel for removal. For a typical 20-panel residential system, that’s $4,000 to $10,000 before accounting for additional costs like removing mounting hardware, inverters, or batteries, which can add another $200 to $1,000. Labor rates vary by region, generally running $75 to $150 per hour.
These costs are worth planning for in advance. Some utility-scale solar projects set aside decommissioning funds from the start, and residential homeowners benefit from the same forward thinking, particularly if the panels are approaching the end of their useful output.
Recycling Is Growing but Still Limited
Solar panels contain recoverable materials like silicon, silver, copper, aluminum, and glass. In theory, up to 90% of a panel’s materials can be reclaimed. In practice, only about 10% of decommissioned panels in the U.S. have been recycled to date, according to data compiled by the National Renewable Energy Laboratory. The rest end up in landfills.
The gap exists because recycling solar panels is still more expensive than landfilling them in most cases, and the volume of panels reaching end-of-life has been relatively small so far. That’s changing fast. The first major wave of residential solar installations from the early 2000s is approaching the 25-year mark, and the waste volume is projected to grow dramatically in the coming decade.
Specialized recycling facilities do exist. Companies like First Solar operate closed-loop recycling for their thin-film panels, and a handful of third-party recyclers handle crystalline silicon panels. But the infrastructure hasn’t scaled to match what’s coming.
Hazardous Materials in Old Panels
Solar panels contain small amounts of lead and cadmium, both of which are toxic at high concentrations. The EPA classifies panel waste as potentially hazardous under federal resource conservation law if these metals leach out at concentrations above certain thresholds. Whether a specific panel qualifies as hazardous waste depends on testing, not a blanket rule.
This matters for disposal. Panels that fail toxicity testing must be handled as hazardous waste, which is more expensive and more regulated than standard landfill disposal. The EPA announced a rulemaking effort in late 2023 to add solar panels to “universal waste” regulations, a classification that would simplify recycling requirements and make it easier for recyclers to handle panels without full hazardous waste permits. That rule is still in development.
The Second-Hand Market
Panels that still produce power at reduced capacity have value to certain buyers. An emerging secondary market channels decommissioned panels into off-grid applications like powering sheds, workshops, boats, or RV setups where peak efficiency isn’t critical. Some panels are exported for rural electrification in developing countries, where even 80% output from a used panel is far better than no electricity at all.
Selling used panels isn’t as straightforward as listing them online, though. Buyers need to know the panel’s remaining output, and there’s no standardized testing or certification for secondhand panels yet. Still, if your panels are in decent physical shape at 25 years, selling or donating them is a more practical and environmentally sound option than sending them to a landfill.