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When you buy solar panels, you are buying something that will sit on your roof for decades. That is both the appeal and the risk. The panels themselves have no moving parts, which is why they last as long as they do. But they do degrade, slowly losing output year after year as UV exposure, heat cycling, and moisture take their toll.
The question is not really "how long do they last?" because technically they keep producing some power for a very long time. The real question is: how much output do they lose, how fast, and at what point does replacement make more sense than keeping them?
This guide covers the real-world lifespan of solar panels and inverters in Australian conditions, what the warranties actually guarantee, and how to tell when your system is past its useful life.
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How solar panels degrade over time
All solar panels lose a small amount of output each year. This is called degradation, and it is a normal, expected process. The rate depends on the panel quality, the technology used, and the conditions they are exposed to.
Modern Tier 1 panels degrade at roughly 0.4% to 0.5% per year after an initial first-year drop of about 1% to 2%. This means a panel rated at 400W will produce around 350W after 25 years, still generating useful power but noticeably less than when new.
| Year | Expected output (400W panel) | % of original |
|---|---|---|
| Year 1 | 392W | 98% |
| Year 5 | 384W | 96% |
| Year 10 | 374W | 93.5% |
| Year 15 | 364W | 91% |
| Year 20 | 354W | 88.5% |
| Year 25 | 344W | 86% |
| Year 30 | 334W | 83.5% |
These figures are based on typical degradation rates for monocrystalline PERC panels, the most common technology installed in Australia today. Older polycrystalline panels degrade slightly faster, at around 0.5% to 0.7% per year.
Newer N-type panels (TOPCon and heterojunction) have lower degradation rates, some as low as 0.25% to 0.35% per year. These panels carry stronger performance warranties and are expected to retain more output over their lifetime.
How Australian conditions affect panel life
Australia's climate is both a blessing and a challenge for solar. The abundant sunshine means higher energy production, but the intense UV radiation and extreme heat put panels under more stress than they would face in milder climates like Germany or the UK.
UV degradation
Australia receives some of the highest UV levels on Earth. Prolonged UV exposure causes the encapsulant (the material surrounding the cells) to yellow and become less transparent, reducing light transmission to the cells.
Thermal cycling
Panels heat up during the day and cool at night. This daily expansion and contraction stresses solder joints and cell connections. In regions with large day-night temperature swings, this effect is more pronounced.
Moisture and humidity
Coastal and tropical areas expose panels to salt spray, high humidity, and driving rain. Over time, moisture can penetrate panel seals and cause corrosion of internal connections, a process called potential-induced degradation (PID).
Hail and storms
Australian panels must meet IEC standards for hail resistance (25mm ice balls at 23m/s). Quality panels handle standard hail well, but extreme hail events can crack cells or glass, particularly on lower-quality panels.
Lifespan of each component
A solar system is more than just panels. Each component has its own lifespan, and understanding this helps you plan for maintenance and replacements over time.
| Component | Expected lifespan | Replacement cost |
|---|---|---|
| Solar panels | 25-30+ years | $800-$2,000/kW |
| String inverter | 5-12 years | $1,500-$3,500 |
| Microinverters | 15-25 years | $200-$350 each |
| Battery (lithium) | 10-15 years | $5,000-$16,000 |
| Mounting system | 25-30+ years | $500-$2,000 |
| Wiring and connectors | 20-25 years | $200-$800 |
The inverter is almost always the first component to fail or need replacement. If you have a string inverter, plan to replace it at least once during the life of your panels. This is a good opportunity to upgrade to a hybrid inverter that supports battery storage. See our upgrading guide for more on this.
When panels do eventually reach end of life, they should be recycled responsibly rather than sent to landfill. Australia is building out solar panel recycling infrastructure, and some states now require it.
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Solar panel warranties explained
Solar panel warranties come in two types, and understanding the difference matters when something goes wrong.
verifiedProduct warranty (12 to 25 years)
Covers manufacturing defects such as delamination, junction box failure, frame corrosion, and cell cracking. If your panel fails due to a defect within this period, the manufacturer must repair or replace it. Premium panels like SunPower, REC, and Q CELLS offer 25-year product warranties. Budget panels typically offer 10 to 15 years.
speedPerformance warranty (25 to 30 years)
Guarantees minimum power output over time. A typical performance warranty guarantees at least 80% to 87.4% of rated output at 25 years. If your panels drop below this threshold due to abnormal degradation (not dirt or shading), the manufacturer must compensate. Premium panels with N-type cells now offer up to 92% output at 30 years.
There is a third warranty that is equally important but often overlooked: your installer's workmanship warranty. This covers the installation itself, including wiring, mounting, and roof penetrations. It typically runs 5 to 10 years. The catch is that if your installer goes bust, this warranty goes with them. Over 200 Australian solar companies have collapsed since 2011, leaving roughly 650,000 households without workmanship coverage. You can check your installer's status on our collapsed companies tracker.
When to consider replacing your panels
Most solar panels do not need replacing for 25 years or more. But there are situations where replacement, rather than repair, makes sense.
Output has dropped below 70% to 75% of the original rating, confirmed by professional testing.
Visible physical damage: cracked glass, delamination (cloudy patches where the layers are separating), or brown/yellow discolouration across multiple panels.
The cost of repairing individual panels exceeds the value of the remaining output over their expected life.
You are upgrading your system significantly (new inverter, battery, more capacity) and the old panels are the bottleneck.
The panels use outdated technology and replacement with modern panels would significantly increase output from the same roof space.
In most cases, the inverter will need replacing long before the panels. If your system is 10 to 15 years old and performing well, the smarter investment is usually an inverter upgrade or battery addition rather than panel replacement. Our upgrading guide walks through the decision in detail.
Frequently asked questions
How long do solar panels last in Australia?
Most quality solar panels last 25 to 30 years and continue producing power beyond that, just at reduced output. The harsh Australian sun and heat can accelerate degradation slightly compared to cooler climates, but modern panels are designed to handle it. Tier 1 panels typically degrade at 0.4% to 0.5% per year.
What is the difference between a product warranty and a performance warranty?
A product warranty covers manufacturing defects, typically for 12 to 25 years. A performance warranty guarantees minimum output levels over time, usually 80% to 87.4% of rated output at 25 years. If your panels drop below the guaranteed output, the manufacturer must repair, replace, or compensate.
Do solar panels stop working after 25 years?
No. The 25-year mark is when warranties typically expire, not when panels stop working. Most panels continue generating electricity well beyond 25 years, though at reduced output. Studies of panels installed in the 1990s show many still producing at 80% or more of their original capacity.
What causes solar panels to degrade?
UV exposure, thermal cycling (heating and cooling each day), moisture ingress, and potential-induced degradation (PID) are the main causes. Australian conditions, with intense UV and high temperatures, put panels under more stress than cooler climates, making panel quality and installation quality particularly important.
When should I replace my solar panels?
Consider replacing panels when output drops below 70% to 75% of their original rating, when physical damage is visible (cracks, delamination, discolouration), or when the cost of repairs exceeds the value of the remaining output. For most systems, the inverter will need replacing long before the panels.
How long do solar inverters last?
String inverters typically last 5 to 12 years, while microinverters can last 15 to 25 years. The inverter is almost always the first major component to need replacement. Budget for an inverter replacement at least once during the life of your panels.
The next step
If you have any questions about the information in this guide, feel free to get in touch:
Email: hello@whysolar.com.au
Tel: +61 455 221 921
If you're considering solar panels or batteries for your home, Jay and the team can help you get quotes from trusted, pre-vetted local installers:
Written by
JaySolar Evangelist
Passionate about making solar simple and accessible for every Australian household. Jay breaks down complex energy topics into practical advice so homeowners can make confident decisions about solar, batteries, and energy independence.
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