How Long Do Solar Panels Last?
8 - Minute Read
Sep 16, 2022
Installing a solar system on a house is a huge investment, so it’s natural to wonder how long solar panels will last.
The short answer: The industry average lifespan of solar panels usually lasts 25 – 30 years. Past that point, solar panels will continue producing energy but will decline in efficiency. There are possibilities for solar panel recycling and re-use, though.
Let’s take a deep dive into what you can expect from a solar array long term. We'll also answer the question, "How long do solar panels take to pay for themselves?" and explore the factors in solar panel lifespans, the life expectancy of solar panel batteries and the investment payoff in other parts of your solar system.
What Is The Average Life Expectancy Of Solar Panels?
The industry standard expected lifespan is 25 – 30 years. Manufacturers factor in a degradation rate of 0.5% per year for solar panels, according to the National Renewable Energy Laboratory (NREL).
However, it's important to note that the system won’t just stop working after the 30-year mark. It will still produce solar power, but energy production will likely significantly decline. After 30 years, warranties tend to expire as well.
Solar systems can also benefit your home by providing passive cooling and shielding the roof from some of the elements. However, if you’re mounting a photovoltaic (PV) energy system on your roof, keep in mind that your solar system will likely outlast a traditional shingle roof. You might consider re-roofing while installing the solar energy system.
Factors That Impact Solar Panel Lifespan
Several attributes can impact the longevity of your PV panels, including:
- Quality: Choosing the right solar brand matters. Higher quality brands give you the lowest degradation rates but usually cost more. You'll likely get better warranty terms and higher efficiency rates as well. Shop around and investigate various brands that solar installers use before you choose.
- Installation: A skilled solar installer can ensure that your system is connected and racked correctly. This means the installer mounts them on the roof or a free-standing rack the right way, safely and at the optimal angle for your roof.
- Maintenance: Panels can also face power loss due to the elements – snow, dirt, dust and other particles. Solar panels don’t require much maintenance, but regular cleaning can help maintain their efficiency.
- Climate: Extreme cold, heavy rain, ocean salt spray and snow can shorten a solar panel system’s lifespan. It's a good idea to learn more about solar panel lifespan from solar installers who are familiar with the climate in your area.
Type Of Solar Panel: Different types of solar panels have different lifespans. The monocrystalline solar panels that are most common on homes typically have the longest life.
You'll also need to consider the individual components of your solar panel to determine their lifespan. For example, you'll want to consider batteries, inverters and mounting – all important parts of a functioning solar panel array. We'll go over these factors in the next sections.
How Long Do Solar Batteries Last?
Solar batteries can supplement your energy needs – particularly during peak hours – without having to rely on the grid (or you can supplement the grid as well). Batteries will store solar energy so you can use it when rates are higher from your utility company and when the sun isn’t shining.
You can also use backup batteries in situations like blackouts. While your solar panel system will be off to protect utility workers during outage events, your battery can still supply stored power to your home. Many master-planned communities equip homes with solar panels and backup batteries to create “virtual power plants” to lessen the burden on utilities.
The lifespan of batteries for solar systems depends on the battery chemistry and in some cases, it also depends on maintenance. Home solar battery units last anywhere between 5 – 15 years. You'll have to plan on replacing your solar panel batteries before the 20- to 30-year lifespan is up on your solar power system.
You can consider several battery chemistries, including lithium-ion, nickel-cadmium and lead-acid batteries. Let's go over the attributes of several battery types:
Lithium-ion batteries for solar panel systems contain an intercalated lithium compound and electrolytes. Lithium ions move through the electrolytes to the positive terminal, where they discharge and reverse direction to charge the battery.
Lithium-ion batteries, like those used everywhere from cell phones to aircraft, are considered the most efficient right now. Some lithium-ion home storage batteries are recycled from electric cars to go into solar panels.
Lithium-ion batteries have warranties that exceed 10 years and have been known to last past 20 years in residential applications. They require little maintenance, but they’re also one of the most expensive options.
Lead-acid batteries contain cells that contain porous lead in a sulfuric acid and water solution. The batteries transform the lead into lead sulfate crystals, then back to the lead and into sulfuric acid.
Lead-acid batteries are the cheapest option. You can recycle them, but they require regular maintenance. Due to maintenance, it’s hard to put a number on how long they last, but 5 years is a common estimate.
Lead-acid batteries are a good option for those looking for lower upfront costs, but know that these will need to be replaced more frequently than lithium-ion batteries.
Nickel-cadmium batteries for solar systems work through an alkali solution that contains nickel and cadmium. It charges and discharges the elements as positive or negative energy is introduced.
Nickel-cadmium batteries are durable, but it's important to understand that cadmium is extremely toxic, which means that you may find it a challenge to dispose of them.
However, the major benefit to nickel-cadmium batteries is that if they are properly used, which means fully discharging them before recharging, they can last for decades.
Some experts recommend nickel-cadmium batteries for their high capacity, long life and small design. If you're not sure which direction to go, ask your panel installer which type of battery they recommend.
How Long Does It Take For Solar Panels To Pay For Themselves?
The return on investment (ROI) of solar panels depends on a number of factors, including the following:
- Home efficiency: Your home’s efficiency will play into your ROI, so an inefficient home will make a solar panel system take longer to recoup the investment. You can make your home more efficient by replacing high-energy appliances with more efficient appliances, installing a programmable thermostat, adding insulation, installing new doors and windows and other energy-conscious upgrades.
- Service fees: Many utility companies charge a service fee for allowing solar owners to use the grid as a battery. That will affect how long it takes for solar panels to pay for themselves.
- Energy production from your solar system: The amount of energy your system produces over the course of time also affects how much money you save.
- Incentive opportunities: Utility companies across the nation offer different incentives for home solar owners. For example, net metering makes it possible for some solar owners to profit from their investment. Net metering involves a billing mechanism that credits solar energy system owners for the electricity they add to the grid. You are only billed for your "net" energy use. However, not all utility companies offer net metering. In addition, you may be able to earn tax credits at the end of the first year that you get your solar system. If you connect and operate your solar system by December 31, 2032, and if you are eligible for such tax credits, you could claim a tax credit of up to 30% of the installation costs.
- Total system cost: Depending on the entire cost of your system, it may take you more or less time to pay it off. Ask yourself how much your total system costs before you implement potential tax credits like the federal solar tax credit to factor in the total payoff and ROI time.
- Cost of electricity: Knowing the cost of electricity factors into your system solar payback time frame. Estimate your annual savings to get the number of years it will take for your solar savings to equal the net cost of the system. Electricity rates increase over time, and when some states don't offer net metering, it can take more time for you to recoup your costs.
What About The Other Parts In The System?
What other components of a solar panel system affect its longevity? Let's go over inverters and mounting as well and the definitions of each.
The inverter is one of the key components in a solar system. It converts direct current (DC) electricity produced by your solar system into alternative current (AC) power that the home and grid can use.
There are three types of inverters: central inverters, string inverters and microinverters.
- Central inverters: Installers typically mount central inverters to the floor or mount them to the ground. Central inverters usually have a warranty of 5 years.
- String inverters: Unlike central converters, which are usually mounted on the floor or ground, string inverters typically go on a wall or other vertical structure. String inverters usually have a warranty of 10 years.
- Microinverters: Microinverters do the same thing as central and string inverters but they are connected to a single solar panel for maximum control and reliability. They are more expensive than the other two types of inverters. They typically have a 25-year warranty.
Ultimately, solar inverters in general usually last between 10 – 12 years and you typically must replace them at least once over your solar system's lifetime.
Solar panel mounting equipment also has its own lifespan. There are usually two types of solar panel mounts or racks – ground mounted and roof mounted. Both types sound exactly like what they are. A ground-mounted solar power system refers to a system of solar panels mounted on the ground on your property, whereas installers put roof-mounted solar panels on the roof of your house.
Warranty periods vary – they can go up to 25 years. Typically, solar panel racks are sturdy and maintenance-free. They will usually last the lifetime of your solar array.
The Bottom Line On The Life Of PV Panels
The industry standard lifespan of solar panels usually ranges from 25 – 30 years. Manufacturers usually estimate a 0.5% per year degradation rate for solar panels, though your system will still produce solar power after that time. Solar panels will continue producing energy after their standard “lifespan” but will decline in efficiency.
Several factors impact the life of your solar panels, including solar panel quality, installation, the maintenance on your panels and the climate in your area. You'll need to consider your home's efficiency, service fees, the amount of energy your solar system can produce, incentive opportunities, total system cost including batteries and inverters and the cost of electricity.
To sum up, you can't place a hard number on the life expectancy of solar panels until you consider all the unique factors that contribute to your specific solar panel array.
Instead of asking "What is the lifespan of a solar panel?" you may want to instead ask, "What is the lifespan of my solar panels?"
It's a good idea to consider every factor to get an idea of how long all of the components of your solar panels will last. Ancillary parts can wear down and affect the efficacy of your panels – even if your panels themselves still work well. Talk to your installer to learn more (before you make decisions about which parts to buy) and how it interrelates with your entire system. As a homeowner, you likely want the best combination of panel affordability and longevity that you can get.
Ready to buy your own solar system? Learn more with Rocket Solar℠.