Solar panel lifespan is usually 25 to 35 years in practice, because panels rarely stop working outright. Their output slowly declines, and field studies put the typical loss at around half a percent per year.
This page belongs to the guide to flexible solar cells. It is an independent explainer and is not affiliated with any solar maker, installer or utility.
What solar panel lifespan really means
A panel does not have a switch-off date. A pv magazine series on panel life notes that there is no specific “end date” for a panel, and that the loss of production over time is what often forces equipment retirements. A panel is worn out when its output has fallen too far to be worth keeping on the roof, or when something breaks that is not worth repairing.
Expectations have moved upward. A US Department of Energy page on end-of-life management says a Berkeley Lab survey of US solar industry professionals shows the average operational lifespan of a solar panel has increased from around 20 years in 2007 to 25-35 years in 2025. The same page notes that most PV systems are still in the early years of their expected operational lifetime, so the real-world record for modern systems is still being written.
Utility-scale plant owners hold similar views. A June 2020 pv magazine report on another Berkeley Lab survey said industry participants expect utility-scale solar plants to have a useful life of 32.5 years, up from 21.5 years in 2007.
How fast solar panel output declines
The yardstick is the annual degradation rate: the share of output a panel loses each year. One reference point is a review by researchers at the US National Renewable Energy Laboratory. According to the laboratory’s publication record, nearly 2000 degradation rates, measured on individual modules or entire systems, were assembled from the literature, showing a median value of 0.5% per year.
A newer dataset points the same way, with a slightly higher figure. A 29 Jan 2024 pv magazine report on the laboratory’s fleet study covered data from 25,000 inverters across almost 2,500 commercial and utility-scale PV sites in 37 states and US territories. The researchers found a median loss in performance of 0.75% per year, and 90% of systems lost less than 2% per year. The mean age of the systems was five years, so the figure describes relatively young plants rather than finished lifetimes.
Long-running outdoor tests give a picture of a whole lifetime. A 14 Dec 2020 pv magazine report described a laboratory test in which cadmium telluride modules, after 25 years, showed long-term degradation of 0.5% a year and an efficiency of around 88% of the original panel performance.
| Study or test | What was measured | Reported rate |
|---|---|---|
| NREL literature review | Nearly 2000 rates, median | 0.5% per year |
| NREL fleet study (reported 29 Jan 2024) | Commercial and utility sites, median | 0.75% per year |
| NREL fleet study, cooler climates | Median in cooler temperature zones | 0.48% per year |
| NREL fleet study, hotter climates | Median in hotter temperature zones | 0.88% per year |
Table data: the NREL degradation review and the pv magazine report on the NREL fleet study.
Put into plain terms, a pv magazine article from 05 Aug 2025 says that at the benchmark rate of 0.5% each year a 20-year-old panel is capable of producing about 90% of its original capability. It adds that premium panels with a rate of about 0.3% per year could still produce 93% of their original output after 25 years, while a higher-degradation example at 0.80% per year could produce 82.5%.
What makes panels degrade faster
Degradation is not one process. It is several, and which one dominates depends on the panel, the climate and the installation.
Heat matters. The NREL fleet study found that systems in hotter temperature zones lost 0.88% per year against 0.48% per year in cooler ones. Severe weather adds to it: hail greater than 25 mm in diameter, winds over 90 km/h and snow deeper than 1 meter were found to lead to greater annual performance losses, for example through mechanical stresses cracking solar cells.
Heat also acts through repeated expansion and contraction. The pv magazine series on panel life explains that when it is warm, materials expand, and when the temperature lowers, they contract, which slowly causes microcracks to form in the panel over time, lowering output. In a PVEL analysis of 36 operational solar projects in India, the average annual degradation was 1.47%, but arrays in colder, mountainous regions degraded at 0.7%. The same article reports a one-time loss of 1-3% in efficiency from light-induced degradation, which occurs within the first hours in the sun.
Climate does not fix the outcome on its own. The NREL review describes a stand-alone system in the desert climate of Libya with a degradation rate of approximately 1%/year after 30 years, as set out in the review’s regional survey. That is well above the median of the whole literature, yet the system was still operating after that long.
Panels have no moving parts and need very little maintenance. Clearing snow is the one chore that can do harm, since scratching the glass surface would reduce output. Portable and camping panels are handled and folded far more than roof panels, and the guide to portable solar panels covers how that changes what to expect from them.
Warranties: what 25 years does and does not promise
Two kinds of promise come with a panel. A product warranty covers defects, and a performance warranty promises that output will not fall below a stated level over time. The 05 Aug 2025 pv magazine article reports NREL’s statement that the industry standard for manufacturing warranties is 25 years on a solar module. It also cites an NREL study of over 50,000 systems installed in the United States and 4,500 globally between 2000 and 2015 that found a median failure rate of 5 panels out of 10,000 annually, and notes that systems installed between 1980 and 2000 had a failure rate double the post-2000 group. Reliability has improved over time.
Warranty terms have been lengthening. The 2020 report on the NREL outdoor test said that one cadmium telluride maker used the results to support extending its module power output warranty from 25 years to 30 years. The same report adds that most solar companies haven’t tested their panels for the actual duration of the warranty term. A warranty is therefore a statement about what the maker will stand behind, not a measured fact about the panel.
Warranty paperwork differs by country and by maker, and the datasheet of a specific panel is the document that states its terms. Certification also matters: panels that meet the IEC 61215 standard undergo a mechanical load test for wind and snow and climate tests covering hot spots, UV exposure, humidity-freeze, damp heat and hail impact.
Inverters usually wear out before panels
The part of a solar system most likely to need replacing is not the panel. A 06 Aug 2025 pv magazine article on inverters says that while solar panels can last 25 to 30 years or more, inverters generally have a shorter life, due to more rapidly aging components. It cites EnergySage for a typical centralized residential string inverter lasting about 10-15 years, with standard warranties of 5 to 10 years, many with the option to extend to 20 years.
Microinverters, which sit behind individual panels, are reported to do better: the same article says they can often last 25 years, nearly as long as their panel counterparts, though it remains to be seen if the equipment will fulfill its 20+ year promise. A common source of failure in inverters is the electro-mechanical wear on the capacitor, and a kWh Analytics study cited there found 80% of solar array failures occur at the inverter level. When a system stops producing, the inverter is the first suspect.
The article recommends installing the unit in a cool, dry place with lots of circulating fresh air, and scheduling an inspection through a licensed solar installer every five years. Opening an inverter or touching array wiring is work for a qualified electrician or installer.
Newer cell types, repowering and end of life
Cell types with a shorter field history have less long-term data behind them. When Technology Review wrote about the thin-film gallium arsenide solar cells of Alta Devices on June 21, 2011, it noted that the company still needed to demonstrate that its high-efficiency cells would last for decades when exposed to the elements without a significant degradation of their performance, according to the 2011 report. A record efficiency says nothing by itself about how many years a cell keeps it.
When a system reaches the end of its useful life, owners sometimes act before it has failed. The Department of Energy page describes repowering, in which consumers and plant operators upgrade their solar panels before the warranty period expires or to take advantage of technological improvements. The same page says weather damage and installation errors are expected to accelerate end-of-life issues.
Disposal is a growing question. The Department of Energy page cites a projection that cumulative PV waste in the United States will be between 0.17 and 1 million tons by 2030. It adds that recycling processes for silicon and cadmium telluride modules exist, but in the United States the total cost of recycling is still generally greater than the cost of disposing of them in a landfill.
Frequently asked questions
How long do solar panels last?
The Department of Energy page, citing a Berkeley Lab survey, gives an average operational lifespan of 25-35 years in 2025, up from around 20 years in 2007, per the DOE end-of-life page. A panel that outlives its warranty usually keeps producing power, at a reduced level.
How much output do panels lose each year?
The NREL literature review found a median of 0.5% per year across nearly 2000 reported rates, per the NREL publication record. Hotter climates sit toward the upper end of the range.
Will a panel stop working after its warranty ends?
No. A warranty is a manufacturer’s commitment and not a failure date. The report on the long-running NREL test shows cadmium telluride modules still delivering around 88% of original performance after 25 years, per the 14 Dec 2020 report.
Which part of a solar system fails first?
Usually the inverter, because its components age more rapidly than the panels do. Panels themselves fail at a low rate.
Does a hot climate shorten solar panel lifespan?
On average it speeds the decline. The NREL fleet study found a clear gap between hotter and cooler temperature zones, and heat-driven expansion and contraction can slowly crack cells inside a panel.
