How soon will your solar panels need replacement?

The lifespan of solar panels explained


Every South African knows that sinking feeling you get when all of a sudden the power goes off. Your plans are ruined and you are instantly in a rubbish mood.

With both planned and unexpected power cuts happening on a regular basis, we are forced to look at alternative sources of electricity.

The use of solar energy is growing in popularity. Considering that solar panels are not cheap, is it even worthwhile to consider them? For how long will you reap the benefits?

How Long Do Solar Panels Last

How long do solar panels last?

Solar power, being a form of renewable energy, converts sunlight into electricity. 


The benefits of switching to solar include:

  • Having electricity when loadshedding strikes.
  • Over time, you will be spending less on electricity.
  • As a form of renewable energy, you can keep using solar power without depleting the Earth’s natural resources. It’s impossible to run out of solar power.
  • Solar power does not require much maintenance. At most you will have to check that your panels are clean once in a while, as they will function best when clean. A good occasional rainstorm is often sufficient to keep them free of dust and debris.
  • All you need to generate power is sunshine, which we have in abundance in South Africa.


Benefits aside, there is still the matter of installing your solar panels. There is no getting away from the fact that you will have to dig deep into your pockets to do so.

Installing solar panels is expensive, so you will want to be sure that it is a worthy investment. The good news is that solar panels last a fairly long time.

The general consensus in the industry is that solar panels last 25 to 30 years. Your solar panels will not simply stop working after reaching a certain age.

Solar panels lose their efficiency at a very slow rate. A study that was conducted in 2012 found that panels that were made after 2000 degraded at a rate of on average 0.5% per year.

This information was gathered from almost 2 000 solar power systems worldwide and in a variety of climates.


In 2019 when Chris Goodall, author and expert on new energy technologies, recorded the performance of his own solar panels. 

“I have recorded the monthly output from the solar panels on our roof for the 15 years since they were installed. 

The records show a very slight decline in the electricity produced of about 0.05% each year. This translates into a fall of just over three quarters of one percent from when the panels were new. 


A panel producing 100 kilowatt hours in 2005 would typically generate 99.2 kilowatt hours in 2020, if the year sees an average amount of solar radiation.” 

Twenty-five to 30 years is the timespan in which the panels are considered to function at their best, but, they will still be able to generate electricity after this time has passed.

In fact, in 2010 it was reported that the world’s oldest solar panel was still working at the age of 60. 

The long lifespan of solar panels is attributed to the fact that panels don’t have any moving parts. Not much can go wrong while they are just sitting there. 

Also, the solar industry is working hard to keep improving their product in order to make it more accessible to consumers.

This means that if you invest in solar panels in your 30s or later, you are likely sorted for the remainder of your life. 

Not a bad deal, considering that we are not seeing any light at the end of the loadshedding-tunnel yet.


9 reasons why solar panels degrade

  1. Light-induced degradation happens when the panels are first exposed to sunlight. This is considered an adjustment phase, and happens within the first 1 000 hours of usage.This initial degradation results in an efficiency loss of one to three percent, after which it will stabilise.
  2. Tiny little cracks can appear in your solar panels because of thermal cycling. In warm weather solar panels will expand, and then contract again when it’s cold, leading to cracks.
  3. Ironically, UV rays from the sun can contribute to degradation. Before you purchase, check that your panels come with UV blockers that will slow down the process.
  4. Strong winds can cause damage, but this should generally not be a problem in solar panels of good quality. It does become problematic in countries that experience wind-related natural disasters like typhoons.
  5. Hot and humid weather is not the solar panel’s friend. Ensure that you buy panels of a high quality, or risk them falling apart in these weather conditions.
  6. Natural wear and tear in the inner workings of the solar panel occurs because of ageing.
  7. Once again not a major problem in our African climate, but it can happen that water finds its way into the joints and seals of your solar panels. Should the mercury then drop to below freezing point, this water freezes and subsequently expands, causing some damage to the panels.
  8. Voltage leaks occur when different components of a system are at different voltages. This will reduce the amount of electricity generated by your solar panels. 
  9. The quality of the materials used to manufacture the panels also play a role. 


Do not fall into the trap of thinking that it’s worthwhile purchasing solar panels that are significantly cheaper than the others on the market. 

This is likely to catch up with you when they don’t remain as efficient as they should.

It is interesting to note that many of the above factors are related to nature. 

Therefore there isn’t much that you can do about it. On the flipside, it is possible to store solar panels for an extended period of time and they will remain as good as the day you bought them. 

The degradation period only starts when they are put to use.


Tips to improve the efficiency of your solar panels

The degradation of solar panels is hardly a train smash, considering that they last a long time with only slight degradation.


You can get even more from your solar panels by taking the following steps to increase their efficiency:

  • Planning Just like you can still get sunburnt on a cloudy day, your solar panels can still function on these days, even if the output will be slightly less. It’s not the same story with shade. So plan wisely, and have your solar panels installed in the sunniest spots possible.
  • Orientation This will also be part of your initial planning. It simply means that your panels need to be positioned in such a way that it will receive optimal sunlight.
  • Solar tracking A solar tracking kit cleverly rotates your solar panels so that they always face the sun. This becomes a bit tricky with a large array of panels.
  • Quality Once again, it’s a general rule of thumb that you will pay more for quality. Be careful who you buy from and do your research. Linked to this is paying for installation. A reputable company will know the correct way to install your panels. Shoddy work will decrease the output of your solar panels.
  • Reflection Ask your chosen solar panel company whether anti-reflective coating is used on their solar panels. Ideally as much as possible sunlight must be absorbed, not reflected. For this reason glass makes an effective component in the makeup of solar panels. It only reflects a small portion of light that hits it, and absorbs the rest.
  • Composition Different kinds of solar panels exist on the market. Polycrystalline panels will not cost you as much, but the way they are produced makes them slightly less efficient.

Polycrystalline panels usually have a square cut and a bluish colour.

Monocrystalline panels consist of pure silicon which results in the best performance. These panels are recognised by a rounded edge and a dark colour.

Are solar panels worth the money?

Going solar is pricey, but you can manage how much it will cost you. There is no need to go completely solar all in one go.

You can opt to only use solar energy for parts of your home, or even just solar heating for your pool. You can also choose to add a bit more solar power to your home annually, or as it suits you.

The proven longevity of solar panels allows you the peace of mind you need to invest in this upgrade to your lifestyle.

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