For Australian homeowners, solar panel degradation is a normal, gradual process, typically seeing a 0.25% to 0.9% loss in power output per year from 2026 onwards. While this means your system won’t produce as much power in year 25 as it did on day one, quality panels are still expected to retain 85-90% of their original output after 25 years. Understanding these rates and your warranty rights is crucial for long-term solar investment.
Solar panels are designed to be durable, often lasting 25-30 years or more. However, the harsh Australian climate, with its intense UV exposure and high temperatures, can contribute to this natural decline in efficiency.
What is Solar Panel Degradation and Why Does It Happen?
Solar panel degradation refers to the slow, permanent reduction in a panel’s ability to produce electricity over time. It’s not a sign of failure but an expected part of the panel’s lifecycle.
The primary causes of degradation include:
- UV Exposure: Australia’s high ultraviolet radiation levels slowly break down protective materials on the panel surface.
- High Temperatures: Repeated expansion and contraction from hot weather stress internal cells and electrical connections.
- Extreme Weather: Hail, wind, and storms can cause micro-cracks or damage seals, leading to moisture ingress.
- Natural Ageing: All materials within the panel, including silicon cells, encapsulant, and solder joints, slowly change.
- Light-Induced Degradation (LID): A common, initial drop in output (often 1-2%) occurs in the first few days of sunlight, then stabilises.
Expected Degradation Rates in 2026
Modern solar panels have significantly improved degradation rates compared to older models. In 2026, what you can expect largely depends on the quality and technology of your chosen panels:
- Standard Quality Panels: Typically degrade at 0.4% to 0.6% per year after an initial 1-2% first-year drop.
- Premium N-Type Panels: Brands like SunPower Maxeon, REC Alpha Pure-R, Jinko Tiger Neo, and AIKO Neostar boast lower rates, often around 0.25% to 0.40% annually.
- Budget Panels: May see degradation closer to 0.9% per year.
A 2026 UNSW study analysing nearly 11,000 PV systems worldwide found the average system loses about 0.9% of output per year, a figure higher than manufacturer claims for premium panels due to a “long tail” of underperforming systems.
“Most quality panels installed in Australia lose about 0.3% to 0.6% of their output each year… retaining 85–90% of their original power after 25 years.”
Choosing N-type panels over older P-type PERC panels can offer lower degradation rates, particularly in hotter climates. For more on this, read our guide: N-Type vs. P-Type Solar Panels in Australia 2026: Unlock $1,000+ Extra Savings Annually.
Understanding Solar Panel Warranties in Australia
Your solar system comes with multiple warranties, each covering different aspects of your investment. It’s crucial to distinguish between them:
1. Product Warranty (Materials & Workmanship)
This covers manufacturing defects, physical faults like cracked glass, faulty junction boxes, or delamination.
- Duration: Historically 10-12 years, but in 2026, quality residential panels commonly offer 15-25 years, with premium brands extending to 40 years.
2. Performance Warranty (Output Guarantee)
This guarantees a minimum power output over a specified period, accounting for natural degradation. Most reputable manufacturers guarantee at least 80-90% of original output after 25 years.
- Duration: Typically 25-30 years.
- Example: A panel might guarantee 98% output in the first year, then a linear degradation not exceeding 0.35-0.4% per year, resulting in 87.4% output after 25-30 years.
3. Workmanship Warranty (Installation Quality)
Provided by your installer, this covers the quality of the installation itself, including wiring, mounting, and roof penetrations.
- Duration: A minimum of 5 years is required under the New Energy Tech Consumer Code (NETCC). Leading Australian installers often provide 10-20 years.
Comparing Top Panel Warranties (2026)
Here’s a comparison of typical warranties for popular Tier 1 solar panels in Australia in 2026:
| Brand / Model | Product Warranty (Years) | Performance Warranty (Years) | Output at Year 25/30 (%) | Annual Degradation Rate |
|---|---|---|---|---|
| SunPower Maxeon 7 | 40 | 40 | 88.3% @ 40 years | 0.25% |
| REC Alpha Pure-R | 25 | 25 | 92% @ 25 years | 0.25% |
| Jinko Tiger Neo | 25 | 30 | 87.4% @ 30 years | 0.35-0.40% |
| Trina Vertex S+ | 25 | 30 | 87.4% @ 30 years | 0.40% |
| LONGi Hi-MO 6 | 25 | 30 | 87.4% @ 30 years | 0.40% |
Note: Specific warranty terms can vary by model and region. Always check the exact warranty documents provided with your quote.
Your Rights Under Australian Consumer Law (ACL)
Crucially, Australian Consumer Law (ACL) provides automatic consumer guarantees that apply to all solar products and installation services, regardless of any manufacturer or installer warranties.
Under the ACL, products must be:
- Of acceptable quality.
- Fit for purpose.
- Match their description.
These rights cannot be excluded or overridden by a manufacturer’s warranty. If your system fails to meet these guarantees, you are entitled to a remedy (repair, replacement, or refund).
The ACCC indicates that for products with a 25-year performance warranty, a reasonable consumer would expect at least 20 years of functional service, potentially extending your rights beyond the written warranty period.
How to Claim Your Solar Panel Warranty in 2026
Making a warranty claim can seem daunting, but a structured approach can simplify the process:
Step 1: Identify the Issue and Gather Evidence
Accurately determine what’s wrong. Is it a visible defect (e.g., cracked glass), a sudden drop in overall system output, or consistent underperformance over time? Take photos and note specific dates. Check your solar monitoring data for anomalies.
Step 2: Assemble Your Paperwork
This is vital for a smooth claim. Collect:
- Original Purchase Invoice: Proof of purchase and system details.
- Installation Agreement: Details of your installer and workmanship warranty.
- Product & Performance Warranty Certificates: Specific terms from the manufacturer.
- Panel Model & Serial Numbers: Crucial for identifying the exact panels.
- System Monitoring Data: Evidence of underperformance.
Step 3: Contact the Responsible Party
Your first point of contact should generally be the solar installer who sold and installed your system. Under ACL, if you paid one business for both products and installation, that business is responsible for providing a remedy. They should manage the claim with the manufacturer on your behalf.
If the issue is clearly a manufacturing defect (e.g., delamination), the manufacturer’s product warranty applies. If it’s related to power output, the performance warranty is relevant. For installation-related issues (e.g., faulty wiring, roof leaks), the installer’s workmanship warranty applies.
Step 4: Submit a Formal Written Claim
Always put your claim in writing, clearly stating the problem, when it was observed, and what remedy you are seeking (repair, replacement, or refund). Include all supporting documentation. Request a claim reference number and keep records of all communication.
Step 5: What if Your Installer is No Longer Trading?
If your original installer has gone out of business, the situation becomes more complex, but you still have options:
- Contact the Manufacturer Directly: Many manufacturers (especially Tier 1 brands with an Australian presence, like Jinko Solar) will process claims directly.
- Engage an Independent CEC-Accredited Installer: They can assess the system, identify the fault, and provide a report as evidence for your claim.
- Home Building Compensation Insurance: In some states (NSW, QLD, SA, VIC), certain solar installations may be covered. Check your state’s rules.
Step 6: Escalation and Dispute Resolution
If your claim is denied or stalls, you can escalate:
- State/Territory Fair Trading or Consumer Affairs Office: These bodies can provide advice and assist with mediation.
- Clean Energy Council (CEC): If your installer is a New Energy Tech Consumer Code (NETCC) approved seller, you can lodge a complaint.
- Solar Accreditation Australia (SAA): If the installer is SAA accredited, you can lodge a complaint there.
For significant claims, seeking independent legal advice may be necessary. For broader support, consider our guide: Navigating Australia’s Energy Bill Relief and Support in 2026: A Comprehensive Guide.
Cost of Solar Panels in Australia 2026
Understanding degradation and warranties is part of making a sound investment. As of 2026, the average cost for a residential solar system in Australia, after the federal Small-scale Technology Certificates (STC) rebate, is approximately $0.88–$0.95 per watt installed.
| System Size | Average Cost (Standard) | Average Cost (Premium) |
|---|---|---|
| 6.6 kW | $5,000 – $6,000 AUD | $6,500 – $10,500 AUD |
| 10 kW | $8,000 – $10,000 AUD | $10,500 – $12,000 AUD |
Source: Industry price indexes as at July-October 2026.
The federal STC rebate for a 6.6kW system is approximately $2,115 AUD in 2026, but this amount decreases every January and the scheme ends in 2030. State-specific rebates, such as the Victorian Solar Homes Program, can further reduce costs for eligible residents. For more details on available incentives, see: Your 2026 Guide: Claim Up To $15,000 in Energy Rebates Across Australia.
Bottom Line
Solar panel degradation is an inherent and expected aspect of your system’s long-term performance, typically resulting in a minor annual output reduction of 0.25% to 0.9%. By 2026, choosing reputable Tier 1 manufacturers with strong 25-40 year product and performance warranties (guaranteeing 87-92% output after 25 years) is paramount. Always prioritise installers offering robust workmanship warranties (10+ years) and a clear, local claims process. Should an issue arise, meticulously document the fault and contact your installer first, leveraging your rights under Australian Consumer Law, which provides protection even beyond stated warranty periods. Investing in quality components and a reliable installer ensures your solar system delivers significant savings for decades, despite natural degradation.