How long do solar panels last?

However, solar panels degrade slightly each year and output diminishes by between 0.3 – 1.0% per year. When determining how long solar panels will last, an understanding of the degradation rate and performance ratio will tell you how much electricity they will produce at 25-year mark.

Solar panel lifespan

• Solar panels last more than 25 years
• Solar panels degrade slightly each year
• Good panels perform better year on year
• Inverters typically last 10 years

Solar panel warranties and longevity

Most solar panels come with a 25-year performance warranty that guarantees your modules will produce a percentage of their rated output after 25 years. While this warranty can be seen as inferior because it is hard to enforce, the performance ratio figure provides an insight into the anticipated degradation of the panel.

Solar panel degradation

The best solar panels degrade at just 0.3 – 0.4% each year, meaning that after their 25-year warranted lifespan, they operate at up to 90% efficiency when compared to their first year. Inferior modules degrade more quickly at rates up to 1% each year; after 25 years, these panels will produce just 78% of the electricity that they did when first installed.

How long will your solar power system last?

Solar panels may have a lifespan greater than 25 years, but this does not necessarily mean your system will last that long. Why? There are many factors that influence the operation and performance of a solar power system.

Factors that influence the longevity of a solar system

• Solar panel quality
• Inverter quality
• Install practices
• Company selected to install your system

Inverter failure is a common problem with solar systems in their early years, this is particularly the case for cheap systems. Even if you buy a good inverter, it will typically need to be replaced around the 10-year mark.

If you buy inferior solar panels, you risk that they do not perform to their rated output, or worse, not function at all. Cheap solar modules are more susceptible to hot spots that lead to malfunction. Product warranties vary between panels, the top brands provide 20 – 25 years protection but the industry norm is down around 10 – 15 years. However, the risk is that if you select a panel from a manufacturer you haven’t heard of, they may not be in business long enough to honour your replacement claim!

System issues may also arise if the install company you select is not well-versed in the best install practices, this can all sorts of problems including: system failure and safety risks.

The best way to mitigate factors that may impact on your solar system’s lifespan is to select a reputable solar company to supply components and install your system.

Approved solar modules

One way to select a panel that should see it last at least 25 years is to ensure it is approved by the Clean Energy Council. The CEC approves solar modules for supply and install in Australia. If your modules are not approved, you are not permitted to receive the federal solar rebate.

Tips to increase panel efficiency and longevity

There are two ways you can maximise the output of your solar panels and enhance their longevity:

• 1. Use a smart monitor
• 2. Clean your panels

Smart monitor

The first is to monitor the output and performance of your system with a smart monitor. If you don’t buy a smart monitor, your installer may keep a record of your system’s performance for you. A smart monitoring device can alert you to issues with your solar system’s performance.

Clean your solar panels

The cleaner your panels are the better they will operate. It is unlikely you will need to clean your solar panels but doing so will improve the efficiency marginally. It's more important to remove any debris from the modules as this will reduce the risk of potential hot spot issues developing.