How Long Do Solar Panels Last?

How Long Do Solar Panels Last

One of the obvious questions that crop up when thinking about going solar is “how long do solar panels last on average?”. And, this is an essential aspect to understand the value you are getting for the money spent.

Though the lifespan of the solar panel is a vital factor, equally important is the effect of degradation rate on energy generation. The technology used and the quality of the solar cells also play a huge role in their efficiency levels, rate of degradation, and longevity.

Now, coming back to our original question about the average lifespan of a solar panel, the simple answer is “about 25 years”.

Let us delve into the topic a little bit deeper and understand more about it.

What is the average life of a solar panel?

With the technological advances made in the last decade, the lifespan of a solar panel has improved considerably. Today’s solar panels are expected to last for 20-25 years. Some of them last longer, up to 30 years.

However, the lifespan of solar cells doesn’t imply that the cells will continue to work for the said period at the same efficiency level and will stop working one fine day. 

After the installation of solar panels, its efficiency level will continue to decline at a steady rate over the years. Again, the technology used in the manufacture of cells is a crucial factor that determines its rate of decline. When the efficiency levels drop significantly beyond a certain limit, they are no longer considered feasible for use. 

Solar cells will continue to generate electricity for decades unless they are physically damaged by exposure to elements or from debris. The longevity of a solar panel can be attributed to its lack of moving parts, making it impossible for it to malfunction on its own. 

What is the rate of degradation of solar panels?

The solar panel degradation rate varies from brand to brand based on the technology used in its production. The premium high-quality panels using state-of-the-art technology have a lower degradation rate than lower quality ones with outdated technology. 

The lower the degradation rate, the more energy it generates over its lifetime. 

Quality Annual degradation rate Lifetime degradation rate Percentage of original output by the end of the lifetime
Premium 0.3% 6.96% 93.04%
Average 0.5% 11.33% 88.67%
Low 0.8% 17.53% 82.47%

(Lifetime is taken as 25 years for calculation)

The annual rate of degradation indicates the rate of decline of efficiency of the solar panels in a year. This means the panels will generate that much less energy over years, provided other factors remain the same.

How often do you have to replace solar panels?

The degradation rate is an indication of the declining efficiency of solar panels in producing electricity. However, solar panels do not come with an expiry date. 

If exposed to extreme weather conditions, the solar panels may be damaged by sudden expansion and contraction of their various parts. Hailstorms and falling debris can also cause serious damage to them. Rainwater can cause damage if the waterproofing seal is broken by any means.

Most solar panels come with a warranty that covers the damage caused by weather. Unless the solar panels suffer serious damages not covered by warranty, they need not be replaced during their given lifespan. 

How do I know if my solar panels are going bad?

The best indicator of the efficiency of your solar panels is your electricity bill. As long as your energy usage remains the same, you know that the panels are nearing their end and ready for replacement when the electricity bills start climbing up.

The increase in the bill amount is an indication that the solar cells are generating less energy and to bridge the gap, you are drawing more and more energy from the grid

Some solar power systems come equipped with monitors displaying the energy generation. This will make the task much simpler.

What happens to solar panels after 25 years?

Solar panels will continue to generate electricity even after their given lifespan but with declining efficiency levels. A well-maintained solar power system can continue functioning for a few more years.

At some point, it would no longer be productive enough to keep going. As long as your solar panel is generating electricity to meet your energy needs and the panel remains free of physical damage, there is no need to replace them.

However, if your solar system is not able to produce sufficient electricity for your use or the cells are damaged and/or broken, it is time to think about replacing them. 

Due to the hazardous materials used in the manufacture of solar panels and the way they are made for increased longevity, they are inherently difficult to recycle. The adhesives and sealants used in cells make it hard to break them apart.

Almost three-fourths of the solar panel is glass, which is recyclable. With no set guidelines on the disposal of discarded solar panels in most states, many manufacturers are taking on the responsibility.

Is it possible to extend the lifespan of solar panels?

Maintaining solar panels is easy and cheap as they do not have any moving parts leading to wear and tear. Moreover, as they are designed as an outdoor installation, solar panels are built to withstand severe weather conditions like torrential rain, heavy snowfall, high winds, and furious hailstorms. 

Most reputed brands of solar panels come equipped with a comprehensive warranty covering damage from natural causes. Inspecting them periodically to look for issues and getting them addressed immediately can help in extending their lifespan.

Besides keeping the surface of the solar panel clean, routine inspection and prompt repair are all that they require to function at their best.

Here are some pointers to help solar panels function efficiently and increase their longevity.

  • Make sure the solar panels purchased come with robust warranties. Besides equipment warranty that covers manufacturing defects and environmental damages, many panel manufacturers offer production warranties that ensure minimum energy production. While the equipment warranty comes in the range of 10 to 15 years, a production warranty is usually offered for 25 years.
  • Using a reputable installer for the original installation of solar panels goes a long way in getting the best out of it. The connections and insulations need to be done perfectly to avoid damage to the system as a whole.
  • Again, reputable installers provide periodical maintenance checks to ensure the smooth functioning of the system. Routine maintenance checks can warn you about issues like physical damage, disconnections, parts coming loose, and even degradation of panels.
  • Routine washing down is vital to keep the solar panels in top order. If the dust, dirt, and debris are left on the panel surface for long, it may result in scratches and cracks, thus reducing its efficiency and longevity. This may even lead to the panels breaking up.
  • Ensure there are no tree branches right above the solar panels. Not only do they obstruct the sunlight and bring down energy production, but the falling branches can also outright break the panels.
  • Snow left on a panel for long can freeze and induce cracks in them. Too much snow piling up on a solar panel can cause damage from the pressure exerted by its weight.

What about the rest of the components of the solar installation?

Besides the panel, the solar system comprises parts like a mounting system, inverter, and solar batteries. 

Racking system: Made from aluminum or other metals, they are fixed to roofs with nuts and bolts. As they are fully exposed to elements, they may require replacement earlier than solar panels.

Inverter: It may require replacement in 10-12 years. This means, one replacement around the half-lifetime of a solar panel. 

Solar battery: An optional addition to the solar system, batteries usually come with 10-year warranties. Their performance starts declining over the years and their ability to store energy will come down, forcing you to replace them. Again, like inverters, batteries may require replacement once around the half-lifetime of a solar panel.

Bottom line

As most people go solar to save money on energy bills, it is pertinent that the panels are made to last as long as possible. For the environmentally-conscious homeowner, the lack of a proper disposal mechanism for decommissioned solar panels is another incentive to make them work longer. 

The solar panel does not “go bad” overnight. Their functioning and efficiency decline over the years that make replacement necessary at some point in time. With proper care during installation and periodic maintenance, the lifespan of a solar panel can go well beyond its given lifespan.

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