Understanding Solar Panel Degradation: Causes, Impact, and Long-Term Performance
People who buy solar panels expect them to save money over time and work well. Every solar system, nevertheless, loses a little bit of its efficiency with time. Understanding this natural process, which is called “what is degradation in solar panels,” can help homeowners make better choices on solar panels, choose better brands, and protect their investment.
This tutorial explains what is degradation in solar panels is, why it happens, how it impacts your long-term solar output, and what you can do to stop it. The goal is to make everything simple, correct, and truly useful so that every Australian homeowner may make choices that are clear and sure.
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What Exactly Is Solar Panel Degradation?
If you think of what is degradation in solar panels, it will make more sense. Solar panels, like any other outdoor gear, face up to the sun, wind, heat, rain, dust, and swings in temperature every day. These persistent environmental conditions make it harder for the panel to turn sunlight into power over time.
Simply said, solar panel degradation means that each year your panels will make a little less electricity.
Most panels lose 0.5% to 0.8% of their power per year. This indicates that after 25 years, your solar panels should still be able to provide 80% to 90% of their original power.
Why Does Degradation Happen in Solar Panels?
Understanding degradation in solar panels becomes easier when you know what causes it. Here are the major reasons:
- UV Exposure
Solar panels sit under the sun all day. UV rays slowly break down materials inside the panel, causing a drop in efficiency.
- Heat Stress
High temperatures are one of the leading contributors to what is degradation in solar panels. Panels perform best around 25°C. Hot summer days can push temperatures beyond 60°C, causing slight material expansion and performance loss.
- Thermal Cycling
Repeated heating during the day and cooling at night causes metals within the panel to expand and contract. Over time, this creates small cracks, called micro-cracks, which reduce electricity generation.
- Moisture & Humidity
Moisture can seep into older or low-quality panels. This leads to corrosion, cell damage and reduced efficiency.
- Weather Conditions & Storm Damage
Hail, storms, high winds, or falling debris can physically damage panels or scratch the glass surface, affecting output.
- Degradation of Backsheet & EVA
Inside every panel, the EVA layer and backsheet protect the solar cells. Over time, these layers age and discolor, blocking sunlight and impacting performance.
How Much Do Solar Panels Degrade Each Year?
When learning what is degradation in solar panels, it’s important to know actual numbers.
Panel Type | Annual Degradation Rate | Performance After 25 Years |
Monocrystalline | 0.3% – 0.6% | 85–92% |
Polycrystalline | 0.5% – 0.8% | 80–88% |
Tier-1 Brands | 0.25% – 0.5% | 88–93% |
Low-quality Panels | 1% – 1.5% | 60–75% |
Better manufacturing = longer lifespan + lower degradation.
Types of Solar Panel Degradation
- LID – Light-Induced Degradation
This happens in the first few hours of sunlight exposure. Some new panels may lose 1–3% efficiency initially. Good manufacturers reduce this using advanced cell technology.
- PID – Potential-Induced Degradation
Occurs when voltage differences between components cause leakage currents. PID can cause severe performance loss, but Tier-1 panels are built to resist it.
- Thermal Degradation
Long exposure to heat accelerates the breakdown of solar materials.
- Mechanical Degradation
Hailstorms, wind pressure, snow, birds, or impact damage can create cracks or broken cells.
How Does Degradation Impact Your Power Bills?
If you’re researching what is degradation in solar panels, the next question is: “Will it affect my savings?”
The answer: Not significantly, especially if you choose quality panels.
Example:
- A 6.6kW system generates around 26 kWh/day initially.
- At 0.5% degradation, the loss after 10 years is only 5%, meaning you still produce around 24.7 kWh/day.
The financial impact is very small—especially compared to how much money solar saves over 25 years.
How to Reduce Solar Panel Degradation
Choose Tier-1 Solar Brands
TOP QUALITY = LOWER DEGRADATION
Brands with strong manufacturing offer slower degradation rates and stronger warranties.
Get a Professional Installation
Improper wiring, poor mounting, or low-quality workmanship can increase degradation.
Always choose Clean Energy Council (CEC) accredited installers.
Regular Cleaning
Dust and dirt reduce sunlight hitting the panel. Clean them every 6–12 months.
Shade Management
Trimming trees and removing shade helps maintain efficiency.
Install Solar Optimisers or Micro-Inverters
These devices reduce the impact of shaded cells and minimise degradation on system performance.
Weather-Resistant Components
Panels with stronger glass, aluminium frames, and PID-resistant cells degrade slower.
Warranty & Degradation: What to Look For
When researching what is degradation in solar panels, warranties matter.
Solar panels come with:
Performance Warranty (Usually 25 years)
This guarantees the panel will still perform at 80–90% of original output after 25 years.
Product Warranty (10–25 years)
Covers manufacturing defects.
A longer warranty = better quality and slower degradation.
Do All Solar Panels Degrade at the Same Rate?
No—degradation varies by brand, material quality, environment, and installation.
- Hot climates → Faster degradation
- Coastal areas → Higher corrosion risk
- Dusty regions → Lower long-term output
This is why it’s important to know what is degradation in solar panels before buying a system.
Should You Worry About Solar Panel Degradation?
Not really.
Solar panels are made to last for 25 to 30 years and still work well. The rate of breakdown is modest and easy to guess.
Your system will keep saving you money for years to come if you choose high-quality panels and a professional installer like Electrical Masters.
Feel free to contact Electrical Masters for free quotation.
Final Thoughts
Understanding what is degradation in solar panels will help you feel good about your solar investment. Degradation is normal and can’t be stopped, but it is very little in high-quality systems and installations that are properly taken care of.
Your panels will continue work well and save you money long after the warranty ends, especially if you use reliable installers like Electrical Masters and take care of your system.
Frequently Asked Questions (FAQs)
Most high-quality panels degrade at 0.25%–0.8% per year.
You can’t stop it completely, but you can reduce it through maintenance, good installation, and choosing better brands.
Yes. High temperatures accelerate material ageing.
Usually after 25–30 years, or when performance drops significantly.
Cleaning doesn’t reduce degradation, but it improves daily efficiency and maintains performance.
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