How Long Do Solar Panels Last?
Modern solar panels last an average of 25 to 30 years, but it’s not uncommon to see some last even longer.
Durability is a key consideration as you assess the benefits of solar for your home. Understanding how long solar panels last will help you to see why solar is an excellent long-term investment.
Durability and the Solar Payback Period on Long Island
Solar panels save you money by generating electricity and reducing the amount of energy you buy from the grid. When solar panels last longer, you will have more time to enjoy savings, cover the cost of your Long Island solar installation, and generate a return on your investment.
- The solar payback period on Long Island is around 8 years for most homes. This is the time it takes for solar panels to generate savings equal to the cost of installation.
- Everything after the payback period is your return on investment. This money goes back into your pocket for regular expenses, saving, investment, or whatever you want to do with it.
- Solar panels that last longer provide a better return on investment, but solar panels lose efficiency as they age.
What Happens After 25 Years of Solar Panels?
Solar panels lose some efficiency by the time they reach 25 years of service. Most modern solar panels have an efficiency rating between 15% and 20% when new. Solar panel efficiency measures how much of the sun’s energy hitting the panel is converted into electricity. Power Solutions installs America’s leading solar brands, including Q Cells, with an average efficiency rating of 20% to 23%.
Solar panels lose a percentage of their initial efficiency each year, affecting their overall rating. We can track a common scenario based on a standard panel with a 20% efficiency rating:
Solar Panel Efficiency Loss by Year
| Years | % of Original Efficiency Remaining | Example (20% Efficient Panel) |
| New | 100% | 20.0% efficiency |
| 1 Year | 98.5% – 99.5% | 19.7% – 19.9% efficiency |
| 5 Years | 96.5% – 97.5% | 19.3% – 19.5% efficiency |
| 10 Years | 92% – 95% | 18.4% – 19.0% efficiency |
| 15 Years | 89.5% – 92.5% | 17.9% – 18.5% efficiency |
| 25 Years | 80% – 88% (End of Warranty) | 16.0% – 17.6% efficiency |
| 30+ Years | Still producing, gradually declining. | Continues to decline. |
From this, we can see that at 25 years, a solar panel might still have up to 88% of its original efficiency. Although it continues to decrease, you will have already passed the payback period, and energy produced will reduce your electricity bill and positively contribute to your home finances.
Frequently Asked Questions
Why Aren’t Solar Panels More Efficient?
While it might seem that 15% to 20% is a low efficiency rating, it’s actually the highest it has ever been. Our understanding of chemical science and solar panel production methods are the limiting factors. A solar panel, even at 15%, can produce more energy on your rooftop than is used to make the panel.
What Do You Do with Solar Panels After 25 Years?
If your solar panels are still functioning at 16% to 17% efficiency after 25 years, then you will still have several more years of service left. You can have your panels inspected at this time, but otherwise you can simply enjoy the savings.
When Should You Replace Solar Panels?
You should replace your solar panels when they physically degrade or when the savings are negligible. This is usually around 30 years, but it’s not uncommon for panels to last a little longer. You should have your panels inspected by a trusted solar team at 25 years to plan the end-of-life process.
Are Solar Panels Really Worth It?
Solar panels are worth it because they create considerable savings, often in the tens of thousands of dollars over a 25+ year lifetime. You will spend less on your electric utility bill and your panels will pay for themselves before providing a long-term return on investment. You can have true energy independence.
Your solar panel installation on Long Island begins with a free home solar estimate and cost/benefit analysis. Power Solutions (the team you might know as Long Island Power Solutions) offers detailed assessments so you can see all the numbers and decide if solar is right for you.
The Federal Solar Tax Credit, worth 30% of your installation bill, is ending on December 31st, 2025. Now is a crucial time to consider switching to solar. Contact Power Solutions today and let us show you what’s possible with a reliable home solar installation.
