Solar Panel Efficiency Over Time: What to Expect in 10, 20 & 30 Years

Posted on Oct 24th, 2023

Homeowners and businesses alike are turning to solar energy to reduce their carbon footprint and save on energy costs. 

However, as with any technology, solar panels are not immune to the passage of time. 

Understanding how solar panel efficiency changes over the years is essential for making informed decisions about your solar investment. 

In this blog post, we'll explore the factors that influence solar panel degradation and what you can expect from your solar panels in 10, 20, and 30 years. Moreover, we'll provide tips on how to extend the lifespan and improve the efficiency of your solar panels over time.

The Initial Efficiency of Solar Panels

When solar panels are first installed, they are incredibly efficient at converting sunlight into electricity. Modern solar panels typically have an efficiency rate of 15% to 22%, meaning they can convert that percentage of sunlight into usable electricity. The initial high efficiency is a significant selling point for solar panels and makes them an attractive investment.

Understanding Solar Panel Degradation

Solar panel degradation is the gradual decrease in efficiency that occurs as solar panels age and are exposed to various environmental factors. Several factors contribute to solar panel degradation over time:

1. Exposure to Sunlight and Heat

In sunny Orlando, solar panels are exposed to intense sunlight and high temperatures throughout the year. While this is ideal for generating electricity, it also accelerates the wear and tear on solar panels. The constant exposure to UV rays and heat can cause the materials within the panels to break down slowly.

2. Environmental Factors

Dust, dirt, excessive pollen, and other environmental particles can accumulate on the surface of solar panels, blocking sunlight and reducing their efficiency. In a humid climate like Orlando's, mold and algae growth can also be a concern, further impacting panel performance.

3. Potential Physical Damage

Hail, heavy rain, and construction debris carried by strong winds can potentially damage the surface of solar panels, affecting their efficiency. While solar panels are designed to withstand such conditions, extreme weather events can take a toll.

4. Wear and Tear

Over time, the materials and components within solar panels can experience wear and tear. Connectors may loosen, and electronic components may degrade, leading to reduced efficiency.

5. Potential Manufacturer Defects

In some cases, manufacturer defects or quality control issues can affect the long-term performance of solar panels. This highlights the importance of choosing reputable solar panel manufacturers and installation companies.

What to Expect in 10, 20 & 30 Years

Now, let's delve into what you can expect from your solar panels in 10, 20, and 30 years.

Solar Panel Efficiency at 10 Years

After a decade of operation, most solar panels will still perform remarkably well. On average, you can expect a slight reduction in efficiency, typically around 10% or less. This means that your solar panels, which may have had an initial efficiency of 20%, might now be operating at around 18%. Regular maintenance and cleaning can help mitigate this decrease in efficiency.

Solar Panel Efficiency at 20 Years

At the 20-year mark, you can anticipate a more significant drop in efficiency, typically around 20% or less. This means that your solar panels, initially operating at 20%, may now be running at approximately 16%. While this may seem substantial, it's important to note that even at this reduced efficiency, solar panels can still provide valuable energy savings. Consider this a mid-life point for your solar panels.

Solar Panel Efficiency at 30 Years

As your solar panels reach the three-decade mark, they will continue to degrade, with efficiency dropping further, often by 30% or more. This means that solar panels that started at 20% efficiency might now be operating at 14% or less. While the efficiency has significantly decreased, it's essential to remember that solar panels have a long lifespan and can continue to generate electricity, albeit at a reduced rate.

Tips to Slow Down Degradation and Improve Efficiency Over Time

While solar panel degradation is a natural process, there are proactive steps you can take to slow it down and maintain better efficiency over the years. Here are some valuable tips to help you get the most out of your solar panels:

1. Regular Maintenance and Cleaning

One of the most effective ways to slow down degradation is through regular maintenance and cleaning of your solar panels. In Orlando's climate, where dust, pollen, and environmental particles are prevalent, keeping your panels clean is crucial. Schedule routine inspections and cleanings to remove dirt, debris, and potential mold or algae growth from the panel surfaces. Clean panels can capture more sunlight, ensuring optimal energy production.

2. Choose High-Quality Materials

When investing in solar panels, prioritize high-quality materials and reputable manufacturers. Quality panels tend to degrade more slowly over time, providing better long-term performance. Research different solar panel brands and consult with solar experts to select the best options for your needs.

3. Invest in Efficient Inverters

The efficiency of your inverter plays a significant role in your overall system performance. As technology advances, consider upgrading to a more efficient inverter. A higher efficiency inverter can help offset some of the degradation effects and maximize the energy output of your solar array.

4. Implement Shade Solutions

If your solar panels are exposed to prolonged periods of shade, consider implementing shade solutions such as pergolas, awnings, or tree trimming. Reducing shading can ensure that your panels receive more direct sunlight, improving their efficiency.

5. Monitor and Analyze Performance

Install a monitoring system to keep a close eye on the performance of your solar panels. Monitoring allows you to identify any issues or drops in efficiency promptly. By addressing problems early, you can prevent further degradation and maintain optimal performance.

6. Consider Panel Coatings

Some protective coatings are available that can be applied to solar panels to enhance their longevity and reduce degradation. These coatings can help protect the panel surfaces from environmental factors and UV radiation.

7. Professional Inspections

Schedule professional inspections of your solar panel system at regular intervals. Experienced technicians can identify potential issues, loose connectors, or other problems that may contribute to degradation. Timely maintenance can extend the life of your solar panels.

8. Plan for Replacements

Solar panel technology continues to advance, and newer panels tend to be more efficient and degrade more slowly. Consider a long-term plan for panel replacements, taking advantage of improved technology as it becomes available.


While solar panels do degrade as they age, they continue to provide valuable energy savings even after several decades of use. The key to mitigating degradation is regular maintenance, cleaning, and investing in high-quality materials and manufacturing. 

At Solar Soft in Orlando, Florida, we specialize in solar panel cleaning, maintenance, and services to maximize the longevity and performance of your solar panel system. Our experts are here to assist you in keeping your solar panels clean, efficient, and well-maintained for years to come.

If you have any questions about solar panel efficiency, degradation, or would like to schedule maintenance services, don't hesitate to reach out to us. Contact Solar Soft at (855) 925-3267 or email us at [email protected]. Let us help you make the most of your solar investment and ensure your panels continue to provide clean, renewable energy for your home or business.

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