How long do solar panels last?
A comprehensive guide to the life span of a solar panel
Solar panels slowly degrade and lose efficiency over time. While you can expect today’s professionally installed home systems to last for 25 years, many modern solar panels can produce power even longer.
To help you understand the full timeline of a solar panel, let’s take a look at how long they last, the factors that affect longevity and what you can do to maximize your system’s life span.
How long do residential solar panels last?
Most of today’s residential panels produce significant amounts of electricity for 25 to 30 years. Even though they don’t last forever, solar panels typically last long enough to make the initial investment worth it compared to long-term utility costs.
However, the life span of a solar module is variable and depends on the quality of the product and how it’s used. When considering a rooftop installation, keep in mind the following three popular options:
- Rigid PV solar panels: Rigid photovoltaic (PV) solar panels, which tend to last 25 to 30 years, are the most common technology for residential installations. These traditional solar panels are cost-effective and durable against harsh outdoor elements and can be easily affixed to any kind of roof — from asphalt and tile to metal and rubber.
- Solar roof shingles: Also built to last for 25 to 30 years, solar roof shingles are an alternative to traditional panels that can help homeowners maintain the look of an ordinary building. Solar shingles are a good choice if you’re already installing a new roof and want to add some green-energy production. However, they’re typically less efficient than solar panels, and they’re not as available in today’s market.
- Thin-film solar panels: Thin-film solar panels are lighter, more flexible and less expensive than rigid crystalline panels. However, they also have shorter life spans, and they’re generally less efficient than rigid panels or shingles, so they aren’t recommended for residential installations with limited roof or yard space.
The industry consensus: Most solar panels will last 25 to 30 years, depending on how quickly the materials degrade over time.
How quickly do solar panels degrade?
Solar panels lose about 0.5% of their production capacity per year on average, but this rate can be higher in rooftop installations or areas with warm climates. Given an annual degradation rate of 0.5%, an average solar panel can be expected to operate at roughly 95% of its initial efficiency after 10 years.
Manufacturers often factor efficiency degradation into their warranties. It’s common for solar panel warranties to guarantee at least 90% of the panel’s original efficiency after 10 years and at least 80% efficiency after 25 years. While that 25-year benchmark is often considered the end of a solar panel's life, you can potentially continue using an older, less efficient solar panel.
As you compare solar energy companies, keep in mind that solar technology continues to advance and solar panel degradation rates are getting lower and more predictable. Some manufacturers now even guarantee less than 10% degradation over 25 years.
What affects solar panel efficiency?
Beyond expected degradation, there are other internal and external factors that affect a solar panel's efficiency and long-term energy production.
- Panel technology: While solar shingles have an average efficiency of 14% to 18%, the most efficient rigid, crystalline solar panels are nearly 22% to 23% efficient. For photovoltaic panels, monocrystalline (typically black) arrays tend to be more efficient than polycrystalline (typically blue) modules.
- Climate and temperature: In dry areas, dust can seriously affect solar efficiency in the same way that snow on a panel can prevent power generation in cold areas. In both instances, owners can rinse their system off with a garden hose or have professional cleaners rid the panels of obstructions. Like many electronics, solar panels also tend to operate better in cooler environments — degradation levels may actually increase in hotter climates.
- Other system parts: It’s important to remember that panels aren’t the only part of a solar energy system. Properly rated wiring and inverter configurations are necessary for panels to generate the most power long term.
3 tips to make solar panels last longer
Here are three quick tips to help you get the most out of your green energy investment:
1. Work with a reputable solar energy company
Above all else, working with a reputable solar energy company is the best way to ensure you receive a high-quality PV system. Seek out multiple quotes from competing companies and compare their options before rushing into a long-term contract.
The key to solar panel longevity is finding a company that offers long warranty periods and great customer service. Be sure to pick a provider that can help when things go wrong — like when an installation results in roof damage, which happened to a reviewer from California.
2. Protect your panels from potential damage
Don’t install solar panels under overhanging branches or close to trees that could damage the system during an extreme weather event.
Roof-mounted solar systems should also be protected with a “critter guard” that blocks birds, rodents and other pests from getting under the panels and causing harm. You can add fencing to ground-mounted panels to prevent pests from damaging the panels.
3. Monitor solar panel performance
While some people only care to see their solar production reflected in monthly electricity bills, actively monitoring ongoing panel performance can help you identify system inefficiencies and eliminate problems before they get worse.
Today, many solar panel systems include an energy monitoring system with features like smartphone integration and instant digital reporting. These systems let you closely track your solar energy generation to ensure everything is working as it should.
- How often do you have to replace solar panels?
To maintain significant power generation, most solar panels need to be replaced every 25 to 30 years. Modern panels can still produce electricity for years beyond this, but the power generation won’t be as efficient as with a new set of panels.
- Can solar panels be damaged by bad weather?
Yes — though they are built to operate outdoors, significant weather events can damage solar panels. During hurricanes, heavy winds and other extreme conditions, solar panels may malfunction or disconnect from the rest of your system.
- What happens when solar panels are 25 years old?
At 25 years old, the majority of high-quality solar panels will still generate electricity but at a lower efficiency level. At this point, a panel can still be used to produce power, or it can be repurposed or scrapped for parts. Luckily, the panel’s glass (which makes up about 75% of the weight of a panel), aluminum frame, copper wire and plastic junction box can all be recycled.
- Article sources
- ConsumerAffairs writers primarily rely on government data, industry experts and original research from other reputable publications to inform their work. To learn more about the content on our site, visit our FAQ page.
- U.S. Department of Energy (DOE) Solar Energy Technologies Office (SETO), “Extending Solar Energy System Lifetime with Power Electronics.” Accessed May 4, 2022.
- U.S. Energy Information Administration (EIA), “Utility solar photovoltaic capacity is dominated by crystalline silicon panel technology.” Accessed May 4, 2022.
- University of Michigan Center for Sustainable Systems, “Photovoltaic Energy Factsheet.” Accessed May 4, 2022.
- U.S. Environmental Protection Agency (EPA), ”Solar Panel Recycling.” Accessed May 4, 2022.
- National Renewable Energy Laboratory (NREL), “STAT FAQs Part 2: Lifetime of PV Panels.” Accessed May 4, 2022.
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