Good solar panels installed on an Australian roof will keep working for about 25 to 30 years, and often longer. But they will not be making the same power at year 25 that they made on day one, and your inverter will almost certainly need replacing before then.
Most confusion about panel lifespan comes from mixing up three different things. Sorting them out is the whole point of this guide.
The three lifespans people mix up
When a salesperson says “25 year warranty”, ask which one they mean. There are three separate numbers.
1. The performance warranty. This is a promise about output. The manufacturer guarantees your panel will still produce at least a set percentage of its rated power after a set number of years. On panels sold in Australia today this usually runs 25 or 30 years. It does not mean the panel dies at year 25. It means the promise stops there.
2. The product warranty. This covers the panel itself against manufacturing faults, such as delamination, a failed junction box, a corroded frame or a cracked backsheet. This is the shorter number, commonly 10 to 15 years, though some premium brands now offer 25 years or more. This is the warranty you are far more likely to actually use.
3. The physical service life. This is how long the panel keeps making useful power before it is not worth keeping on the roof. There is no warranty on this. It is usually longer than both warranties, but it depends heavily on the panel, the install and the climate.
Performance warranty vs product warranty
| Performance warranty | Product warranty | |
|---|---|---|
| What it covers | Output dropping below a guaranteed level | Faults in the panel itself |
| Typical length in Australia | 25 to 30 years | 10 to 15 years, up to 25 on premium panels |
| What triggers a claim | Measured output below the warranted curve | Panel is defective or physically fails |
| How easy is it to claim | Hard, you need testing to prove low output | Easier, the fault is usually visible |
| Labour and removal costs | Usually not covered | Usually not covered, read the fine print |
| Not covered by either | Hail, storm, lightning, install error, animal damage | Hail, storm, lightning, install error, animal damage |
Two practical points. First, neither warranty is worth much if the manufacturer stops trading in Australia, which is why brand stability matters more than a big number on a brochure. Second, a written warranty is not your only protection. The ACCC explains that consumer guarantees under Australian Consumer Law are automatic and cannot be taken away, and they apply on top of whatever the warranty document says. Goods must be of acceptable quality and last a reasonable time given what they are.
What solar panel degradation actually is
Solar panels lose a small amount of output every year. This is normal and expected. It happens because sunlight, heat and moisture slowly break down the materials in the cell and the layers around it.
Panels lose a bit more in their first year than in later years. Manufacturers allow for this separately. According to SolarQuotes’ panel degradation guide, the first year allowance is around 2% for older P-type panels and about 1% to 1.5% for the N-type panels that now dominate the market.
After that first year, the warranted rate settles down. SolarQuotes lists the current warranted annual rates as roughly:
- 0.25% a year on premium panels such as REC Alpha Pure and SunPower Maxeon
- 0.35% a year on Aiko Neostar panels
- 0.4% a year on mainstream brands including Jinko, Trina, JA Solar, Canadian Solar and Winaico
- 0.55% a year on some lower tier products
So when people say modern panels degrade at “0.3% to 0.7% a year”, that is the honest range. Anything warranted above 0.5% is a signal to look harder at the rest of the quote. If you want help judging panel specs, our guide to the best solar panels in Australia covers efficiency, temperature coefficient and bankability.
What your system really produces at year 10, 15, 20 and 25
The table below works the arithmetic through for four different rates. The first two use published warranty terms. The third uses the median field degradation rate for crystalline silicon panels reported by the US National Renewable Energy Laboratory, which is about 0.5% a year. The fourth uses the typical measured rate from a 2026 UNSW study of nearly 11,000 photovoltaic samples, which found systems declining by around 0.9% a year in the real world.
These are our calculations applied to those published rates, not measurements of any one system.
| Year | Premium warranty (1% then 0.25%) | Mainstream warranty (1% then 0.4%) | NREL median field rate (0.5%) | UNSW measured rate (0.9%) |
|---|---|---|---|---|
| 1 | 99.0% | 99.0% | 99.5% | 99.1% |
| 10 | 96.8% | 95.5% | 95.1% | 91.4% |
| 15 | 95.6% | 93.6% | 92.8% | 87.3% |
| 20 | 94.4% | 91.7% | 90.5% | 83.5% |
| 25 | 93.2% | 89.9% | 88.2% | 79.8% |
Put that in kilowatt hours. If your system made 9,000 kWh in its first year, a mainstream panel degrading at its warranted rate would still make about 8,100 kWh in year 25. At the real-world rate from the UNSW data, it would be closer to 7,200 kWh. Check your monitoring app for your own first year figure and scale from there.
The warranted rate is not the rate you get
That last column is the uncomfortable one. The UNSW research on the “long tail” problem found that at least one in five systems degrade at least 1.5 times faster than typical, and roughly one in twelve degrade twice as fast. The worst performers could lose about 45% of their output by year 25, giving a useful life closer to 11 years than 25.
The researchers point to interconnected faults, manufacturing defects that show up early, and small flaws that cause sudden large losses years later. The practical lesson is simple. Warranted degradation is a floor the manufacturer will defend, not a forecast of what your roof will do.
The inverter is the part that usually fails first
Panels have no moving parts and sit there quietly for decades. The inverter is an electronic box full of capacitors and cooling fans, running hot, every day, for hours. It is the component most likely to give out first.
Plan on replacing a string inverter somewhere between year 10 and year 15. Most string inverters sold here come with a 5 or 10 year warranty, and many brands sell a paid extension out to 15 or 20 years. Microinverters and some premium string brands carry longer standard terms, closer to 20 or 25 years, which narrows the gap with the panels.
Budgeting for the replacement
Australian retailer 1KOMMA5 puts inverter replacement at around $3,000 including installation for a typical residential unit, and notes a 3kW and a 5kW inverter cost about the same. Treat that as a real line item in your long term solar maths, not a surprise.
A few things make that bill easier to handle:
- Set money aside from year one. Roughly $250 a year over 12 years covers it.
- Pay for the warranty extension if it is cheap. Registering online for a free extension takes ten minutes and some brands offer it.
- Fit the inverter somewhere cool and shaded. A north or west facing wall in full sun cooks it. A garage wall or the shaded south side is much kinder.
- Ask about compatibility before you buy. If you plan to add a battery later, a hybrid inverter now can save you a second replacement.
- Keep the paperwork. Warranty claims need the serial number, install date and the original invoice.
What shortens system life in Australia specifically
Australian conditions are harder on solar than almost anywhere else. These are the main causes.
Heat. Panels are rated at 25 degrees. A rooftop panel here can sit at 60 to 70 degrees on a summer afternoon. High heat cuts output on the day and speeds up long term breakdown of the encapsulant and backsheet. Panels laid flat against a hot roof with no air gap run hotter and age faster than panels on a properly spaced rail.
Humidity. Moisture getting into the laminate is a major cause of corrosion and delamination. This is a bigger problem in tropical Queensland and the Northern Territory than in Melbourne or Adelaide.
Coastal salt. Salt spray attacks aluminium frames, mounting rails and fixings. If you are within a few kilometres of the ocean, ask specifically for panels tested to IEC 61701 for salt mist corrosion resistance and for marine grade mounting hardware. The Clean Energy Council’s approved modules list shows which models carry that extra certification, alongside IEC 62716 for ammonia resistance and IEC TS 62804 for potential induced degradation.
Hail. Every panel on the approved list must pass IEC 61215, which includes firing 25mm ice balls at the module at 23 metres per second, about 83 km/h. Australian hailstorms regularly beat that. Hail damage is not a warranty matter, it is a home insurance matter, so check that your policy names the solar system.
Cheap mounting hardware. Racking and fixings are the least glamorous part of a quote and the easiest place to shave a few hundred dollars. Poor quality rails corrode, fasteners work loose in wind, and roof penetrations leak. The panels usually outlive the frame they are bolted to.
Poor installation. This is the big one. The Clean Energy Regulator inspects a sample of new systems every year. Its inspections update reports that 18.7% of systems inspected in 2024 were rated substandard, down from 22.6% in 2023 and 24.6% in 2022. The trend is improving, but roughly one in five inspected installs still had something wrong with it. Loose DC connectors, badly routed cable and unsealed roof penetrations are the kind of faults that turn a 30 year system into a 12 year one. Choosing carefully matters, so read our guide on how to choose a solar installer and check the installer’s credentials on the New Energy Tech Consumer Code approved seller directory for the retailer, and check the individual installer’s accreditation with Solar Accreditation Australia, which took over installer accreditation in 2024, before you sign.
Getting the most years out of your system
Nothing here is complicated. Keep the panels reasonably clean, especially if you are under trees or near a dusty road. Check your monitoring app monthly so a dead string or a failing inverter does not go unnoticed for a year. Book an electrical inspection every few years to catch loose connections and corroding fixings early. Our maintenance and longevity guide covers the routine in more detail.
At quote stage, ask each installer for the panel’s warranted first year loss, its annual degradation rate, its product warranty length and the inverter warranty length in writing. Comparing those four numbers side by side tells you more about lifetime value than the headline price does. Our guide on how to compare solar quotes has a full checklist, and you can browse installers by state in our directory.
Frequently asked questions
Do solar panels stop working after 25 years?
No. Year 25 is the end of the performance warranty, not the end of the panel. Most panels keep producing useful power well past that, just at a lower level. Systems installed in Australia in the early 2010s are still running.
What is a good degradation rate to look for?
At 0.4% a year or less after the first year, you are in mainstream quality territory. Premium panels are warranted at 0.25%. Anything above 0.5% is worth questioning.
Will I have to replace my solar panels and inverter at the same time?
Almost certainly not. The inverter typically needs replacing at year 10 to 15, while the panels carry on. Budget them as two separate events, with the inverter first.
Does a 30 year performance warranty mean better panels?
Not on its own. A long performance warranty is cheap for a manufacturer to offer because output claims are hard to prove. The product warranty length is the more revealing number, because that is the one the manufacturer actually has to pay out on.
Is it worth cleaning panels to make them last longer?
Cleaning helps output, not lifespan, in most cases. The exception is bird droppings and thick grime left in one spot, which can create hot spots that damage cells over time. Clear those off rather than scrubbing the whole array every month.
What happens if the panel manufacturer leaves Australia?
Your written warranty becomes very hard to enforce. Your rights under Australian Consumer Law still apply against the retailer or importer who sold you the system, which is another reason to buy from a business likely to still be trading in ten years.
Related reading
- what happens to old solar panels
- how to clean solar panels safely
- string inverters, microinverters and MPPT
About this research
This is independent desk research by Solar Cobber. We did not visit sites, request quotes or accept payment for inclusion. Figures are dated and sourced, and pricing and policy details change, so confirm current terms directly before you sign anything.