How Long Do Solar Panels Really Last? Debunking Common Myths.

Team Solarblocks Energy
November 30, 2023
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How Long Do Solar Panels Really Last? Debunking Common Myths.

Solar panel investing is one of the most cost-effective methods to electrify your home. Also known as PV or photovoltaic panels, solar panels are known to last for more than 25 years. They effectively harness the power of the sun to generate electricity, are eco-friendly, and ensure minimal carbon emissions. Generating solar power is also a cheap alternative to using grid electricity, as it guarantees maximum savings on your utility bills.

Although homes with solar panels were a strange sight even a decade back, today its adoption has mainly increased due to technological advancements.

But a common question remains: How long do solar panels really last?In this blog, we have attempted to create a complete guide on the solar panel’s lifespan and its maintenance and monitoring.

How Long Do Solar Panels Last?The Industry Standard

Per the Solar Energy Industries Association (SEIA), the life expectancy of solar panels is between 25 and 30 years. This does not mean that the panels stop generating electricity after 25 years. Instead their production capacity declines by a significant extent. They continue to absorb sunlight but at a less efficient rate.

The first 25-30 years are hailed as the system’s most valuable life. But they continue to produce power for several more decades, even till the age of 60.

Reputable installers offer product warranties of 25 years which make it a fantastic long-term investment for residents and communities. Solar panels are also sturdy, resilient, and durable, but external factors like rain, hailstorms, debris, and wind can end the system's lifespan early.

Chris Deline, a research engineer at the National Renewable Energy Laboratory said that solar panels "come with 25-year warranties. Further, the materials they're composed of — aluminum and glass, primarily — can be durable enough to last much longer, sometimes 30, 40, or 50 years."

What is the Solar Panel Degradation Rate?

To explain how long panels last, it is important to talk about the solar panel degradation rate.

In the average but worst scenario, solar panel output can fall by 0.8% each year, according to the National Renewable Energy Laboratory (NREL). This is caused by constant exposure to heavy sunlight and weather conditions which declines the performance of the solar system. The speed and output of the panels also degrade over time. The experts measure this as a percentage of the annual power output lost.

A lower degradation rate is better for the solar panel’s lifespan.

The average yearly solar panel degradation rate of 0.8% means that in two years, the output rate will be 99.2% than the original. After the 25-year lifespan, its operating rate will fall to around 82.5%. On the other hand, a degradation rate of 0.5% means that the output calculated after its completed lifespan will be ~87.5%. Hence, you can determine the solar panel’s output after certain years by multiplying the degradation rate by the number of years and subtracting the number from 100%.

The idea of the above-mentioned information is taken from

What Causes Solar Panel Degradation?

While solar panel degradation is hugely responsible for decreasing the life expectancy of solar panels, another common factor at play is thermal cycling. Due to warm or cold weather conditions, things expand or contract. The same can cause microcracks in the solar panel. The panels are also damaged due to extreme and harsh conditions like rain, snow, hail, or strong winds. This is why it is necessary to understand how often do solar panels need to be replaced.

Strong winds can move or flex the panels, but tests like the Dynamic Mechanical Load or DML assess the mechanical strength of the rooftop solar modules. Extreme cold and hot weather can also impact the voltage potential of the solar panels.

Some worry about continual sunlight exposure. In fact, this is called Light Induced Degradation or LID. After the initial setup, the PV modules lose their performance after the first hours of exposure to sunlight. They degrade by 1% - 3%. However, modern-day manufacturers create panels with UV ray blockers to protect against extreme damage.

About Solar Panel Warranties

Solar warranties are directly related to the life expectancy of solar panels. This should cover an:

  • equipment/product warranty
  • performance warranty
  • installation warranty
  • power warranty

Defects happening outside the manufacturer’s control are not covered under these warranties.

Which Solar Panels Have The Longest Lifespan?

The Bloomberg New Energy Finance Corporation (BNEF) categorizes solar panels into various categories -

  • Tier 1 panels
  • Tier 2 panels 
  • Tier 3 panels

However, it only explains the Tier 1 panels and not the rest. Tier 1 panels are designed by manufacturers with at least five years of experience and reputation. They are expensive but have longevity and a high-efficiency rating, which makes them a worthwhile investment.

Monocrystalline and Polycrystalline panels are classified as Tier 1. The former is more expensive with a peak output and a low degradation rate. The latter is affordable but has lower efficiency.   Solar panels degrade at the rate of 1% every year on average. However, there is a study by the National Renewable Energy Laboratory (NREL) that covered 2000 solar systems in different regions and climates. It found that monocrystalline panels manufactured after the year 2000 showed a 0.4% degradation, which is less than the 1% rate mentioned in the warranties. This proves that solar panels degrade but slowly in the remainder period.

How Often Do Solar Panels Need To Be Replaced?

The average solar panel lifespan is between 25 and 30 years. If you continue using the system after that and notice the energy bills rising, it is an indicator that the solar system is no longer operating proficiently.

This is when you should purchase a new solar system.

Solar panel degradation is inevitable, hence you should be careful to assess its functioning condition. Suppose a solar panel that you initially installed has the capacity to generate 37kWh of energy. But with the passing years, it can only generate up to 30kWh power. This indicates the time for a quick replacement of the system.

Many solar companies also offer trackers to help homeowners monitor their monthly electricity consumption. Once you get the numbers handy, you can easily notice if something is off and understand how often solar panels need to be replaced.

Ways To Enhance Life Expectancy of Solar Panels

  1. Choose the most reputable solar panel installers

Consulting professional solar installers is a must to protect your solar investment. At Solarblocks, our experienced team of solar panel experts guarantees complete solar panel installation and maintenance services. With a client-first model, we provide customized solutions for all, via no middleman, and our products are covered with robust warranties. Our installations are also secure so the system functions at its peak performance. 

  1. Check your usage 

A good rule of thumb is to monitor how much electricity your system is producing. While most systems have a turn-off switch, if you do it unknowingly, you can potentially lose a huge amount of the energy produced. 

  1. Keep the panels clean

Ensure to clean and maintain the solar panels from time to time. Remove any kind of debris lying on them like tree branches, dust, sand or snow, stone pebbles or broken mirror chips, etc. If left for too long, dust and pebbles can scratch the panels, create microcracks, or even break them. 


  1. How long do solar panels last?

According to experts, solar panels last for 25-30 years. 25 years is the standard life expectancy of solar panels. After completing this time, the solar panels start degrading in performance, and the output reduces. Their capacity to absorb the sunlight also lowers. 

  1. What causes solar panel degradation?

Certain factors like product life expectancy, and external factors like continual exposure to sunlight, harsh weather conditions, wind, storm, hail, rain, and snow degrade the internal and external quality of the solar panels. Damaged solar panels from over-exposure to sunlight are called Light Induced Degradation or LID. Conditions like thermal cooling cause micro-cracks on the panels. 

  1. Can you extend the solar panel lifespan?

With frequent maintenance and monitoring, you can easily extend the lifespan of solar panels. Consult professional solar panel installers for routine care and schedule a professional cleaning service to keep the panels free from debris, dust, or tree branches. Work with a reputable solar panel company for guaranteed services. 

  1. How often do solar panels need to be replaced?

You can consider replacing the solar panels after it completes 25 years. Monitor the output of the panels to check their performance and replace them if needed. Always consult an expert during solar system installation. 


Any property can benefit from solar panels, but it is crucial to see if they are value-adding. To ensure your home looks visually appealing with solar panel installation, it's essential to choose the right type with the right color and frame to match the roof. One consideration is to keep the wiring’s visibility to a minimum for aesthetics as well as safety reasons. By taking these steps, you can enhance your home's appearance while reaping the benefits of renewable energy, both now and in the future.

A qualified and experienced engineering design and installation company like Solarblocks can make every decision seem like a cakewalk for you.

Are you considering switching to solar?Visit us for the best roof design for solar panels and type. Drop us an email at for a quote.

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