Table of Contents:
Key Takeaways
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Solar panel performance degrades by 1% to 2% in the first year and 0.25% to 0.55% per year afterward.
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Factors like build quality, environmental conditions, and maintenance can affect solar panel lifespan.
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You can get the most out of your panels by choosing high-quality panels and cleaning them regularly.
Home solar panels provide energy directly from the sun and require minimal maintenance. While they don’t last forever, they do provide guaranteed levels of power for at least two and a half decades. Well-maintained solar panels can last far beyond that point, too. In this article, we’ll break down the average solar panel lifespan and what affects it.
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How long do solar panels last?
Modern solar panels maintain guaranteed power output for 25 to 30 years. All panels lose performance slightly each year, so after 25 years, panel output is usually between 84% and 92% of factory levels.
Your solar panel warranty typically covers 25 years of production, though many systems continue generating power well beyond their warranty period. It’s not like you have to throw 25-year-old panels away. Monocrystalline panels are the most common type today, and they can last up to 40 years with the right maintenance.
What are normal degradation rates?
Output degradation is one of the downsides of solar panels. Leading manufacturers usually guarantee 98% to 99% performance after the first year. Then, they guarantee performance won’t degrade by more than 0.25% to 0.55% per year. After 25 years, this means you’ve only lost about 8% to 16% of output performance.
Here are the main causes of performance degradation over time:
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UV exposure: Yes, even solar panels are damaged by the sun’s radiation over time. UV radiation can break down molecular bonds in the panels on a microscopic level.
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Temperature: Hot weather and wide temperature swings create thermal stress that wears on solar components.
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Microcracks: Moisture can enter older panels through microcracks and reduce system lifetime.
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Light-induced degradation (LID): Monocrystalline cells paradoxically lose some output shortly after installation when receiving the first rays of the sun. This is why panels can degrade 1% to 2% in the first year and then a fraction of a percent after that.
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Potential-induced degradation: Voltage differences between materials inside a solar panel can cause electrons to leak from the system.
Do solar panels make your roof last longer?
Solar panels can protect the roof directly underneath from UV rays, hail, and snow. Nature takes a toll on your roof over time, and solar panels can block its harmful effects. The small air gap acts as a layer of insulation, too. You might even find the room underneath your panels stays at a more constant temperature throughout the year.
That said, installing panels won’t fix issues with your roof. And if you have an old roof, it’s better to replace the roof before adding panels.
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Factors that affect solar panel lifespan
The natural degradation from UV exposure, temperature fluctuations, and potential microcracks can all affect how long a solar panel system lasts. Mild climates tend to help panels last longer even though they don’t provide as much peak sun as hotter climates. We’ll cover some main factors here.
1. Degradation rate
Of course, the degradation rate has a big impact on how long a solar panel system will produce reliable power. A system with a degradation rate of 0.25% can equate to saving hundreds of dollars in energy bills over one with a degradation rate of 0.55% after a couple of decades.
Since power output decreases over time, a solar panel system can boost your home value when the system is relatively new. If you’re selling a home with a 25-year-old system, prospective buyers might worry about having to replace it.
2. Build quality and materials
Manufacturers with the best build quality usually offer better longevity, and they may also offer better warranty terms.
Solar panel manufacturing is divided into three tiers. Tier 1 manufacturers account for 2% of the market and are financially sound enterprises that have been in business for many years. Tier 2 manufacturers are small to mid-sized companies that offer good value.
Tier 3 manufacturers really don’t manufacture the solar cells, they assemble components from third parties. Lower-tier panels, while more budget-friendly, might degrade faster and have shorter warranty periods.
3. Environmental conditions
Your environment can shorten solar panel lifespan through thermal stress and weather exposure. Panels don’t perform the same in all locations.
Even though you get better sunlight in hot areas, high heat can stress solar panels over time. Counterintuitively, temperate zones offer more stable conditions for sustained panel output. High winds, high humidity, and harsh winter weather can all speed up degradation, too,
If you live on the coast, you have to deal with salt air exposure. This can corrode the mounting hardware and frame over time.
4. Maintenance
You have some control over your panel’s lifespan by practicing regular maintenance. The minimum recommendation is to clean your solar panels twice a year. However, if you don’t get much rain during the year, you might have to clean your panels more often to wipe away dust and debris, which can sap efficiency. You’ll also have to clean them more often if you have a flat roof.
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Know your solar panel warranty
Manufacturers offer two types of warranties: performance and product. Performance warranties guarantee minimum solar panel output over a specified period of time like 25 years. Product warranties cover manufacturing defects in materials and workmanship. These usually last from 12 to 25 years.
Below are a few popular solar panel brands along with information on their warranties. These apply to the specific panel models below, and warranties can vary for different panels.
| Manufacturer | Panel model | Output after year 1 | Yearly degradation | Output after 25 years | Performance warranty | Product Warranty |
|---|---|---|---|---|---|---|
| Panasonic | EVERVOLT 370K/360K | 98% | 0.25% | 92% | 25 years | 25 years |
| Maxeon | Maxeon 6 | 98% | 0.25% | 92% | 40 years | 40 years |
| REC Group | Alpha Pure-RX | 98% | 0.25% | 92% | 25 years | 25 years |
| Silfab | SIL - 410 BG | 98% | 0.34% | 90.8% | 30 years | 25 years |
| Qcells | Q.TRON BLK M-G2+ | 98.5% | 0.33% | 90.58% | 25 years | 25 years |
| Jinko | Tiger Neo | 99% | 0.4% | 89.4% | 30 years | 12 years |
| CanadianSolar | HiKu6 Mono PERC | 98% | 0.55% | 84.8% | 25 years | 12 years |
| LONGi | Hi-Mo 5 | 98% | 0.55% | 84.8% | 25 years | 25 years |
Improving solar panel lifespan
The best way to make sure your panels last a long time is to start with well-made panels and maintain them. Here are a few things to keep in mind
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Choose the highest-quality panels in your budget.
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Choose a reputable installer to make sure the panels are installed correctly.
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Clean your panels at least twice a year.
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Trim tree branches that could fall or drop debris and damage your panels.
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Have your solar panels and inverter inspected every few years.
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Consider getting add-on products to protect your panels like mesh bird and critter guards.
Owning solar panels is a long-term investment. Consider the pros and cons carefully because solar panels aren't best for everyone.
Wrapping up: Solar panel lifespan
While solar panel performance degrades at predictable rates, you can expect to get at least 25 to 30 years of high performance out of your system. With good maintenance, you can continue to power your home even after that point.
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FAQ about solar panel longevity
Below are a few frequently asked questions about how long solar panels last:
What happens after 25 years of solar panels?
Solar panels still work after 25 years, just with 85% to 90% of their original output. You might keep using them, or you may want to replace them at that point.
How often do solar panels need to be replaced?
You shouldn’t have to think about replacing solar panels for about 30 years. However, if you add electric vehicles to your home or increase your usage, you might want to upgrade your system before then.
How efficient will solar panels be in 10 years?
Most solar panels from leading manufacturers will be 92% to 95% as efficient after 10 years compared to day one.
Do solar panels need maintenance?
Solar panels need minimal maintenance. This includes cleaning a couple of times a year and inspections every few years to make sure everything looks good.