How Long Do Solar Panels Last?

Written by Saltanat Berdikeeva

Edited by Hannah Hillson

Last updated 03/03/2022

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How Long Do Solar Panels Last?

Solar panel manufacturers typically guarantee the maximum performance of their products for 25–30 years. However, your solar panels may continue to generate electricity for years beyond the guarantee. A solar owner needs to understand the lifespan, deterioration rate, and ways to prolong the life of solar panels.

Lifespan of solar panels

Solar panels do not produce at full capacity during their lifetime and then suddenly stop operating after 30 years. In most cases, they continue producing electricity for many years after the manufacturer’s guarantee. But the power output level after 30 years will be lower compared to day one. The quality of solar panels also plays a role in their durability. High-quality but more expensive panels will have a longer lifespan than cheaper alternatives. For example, a monocrystalline solar array produces more electricity than a polycrystalline panel throughout its lifespan due to its higher efficiency rate.

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What causes the deterioration of solar panels?

Extreme weather, temperature changes, humidity, inadequate installation, manufacturing defects, and insufficient or lack of maintenance can shorten the lives of solar panels. Years of exposure to ultraviolet light (about 7% of sunlight is ultraviolet) can also reduce efficiency of solar panels over time.

The impact of weather cycles on solar panels is unavoidable. For example, damp heat can cause damage to a solar panel encapsulant, an ethylene-vinyl acetate film that attaches solar cells and protects against environmental stress. A worn-out encapsulant can lead to corrosion of solar cells. Heat and cold can cause damage to solder bonds holding solar panels together. After years of exposure to natural elements, solar modules absorb less sunlight and turn less into electricity. 

In addition, the quality of materials used during manufacturing also impacts the degradation rate of solar panels. Some solar panel manufacturers cut down the use of aluminum in solar frames to reduce costs. As a result, frames come out thinner and become more susceptible to degradation. Improper installation, such as exposed wires or a defective racking system— which keeps solar panels attached to the roof— can also reduce output from solar panels.

How fast do solar panels deteriorate?

Your system’s solar production rate decreases each year in tiny increments, called degradation. The best way to measure solar production levels is to monitor output changes in your system every year. According to the National Renewable Energy Laboratory (NREL), solar panels degrade around 0.5% each year. That is the rate at which your solar panels will annually lose their efficiency. It also means they should produce nearly 90% of power after 20 years. The 30-year period is a less accurate benchmark for measuring a panel’s durability than the loss of output over time. You can continue to enjoy savings on your utility bills and produce clean and renewable energy for decades after installing solar panels.

How to make solar panels last longer

The good news is that you can help prolong the lifespan of your solar panels with regular maintenance and monitoring. 

Periodic cleaning and inspection

Accumulation of dirt, dust, pollen, and debris on solar panels reduces their efficiency and power output. While solar panels generally do not require cleaning, it is wise to wash them at least once a year to avoid efficiency loss, especially if you live in a place with infrequent rainfall. Cleaning may even be a requirement of a solar panel warranty. You can hire someone to clean them or do it yourself. It is not difficult to wash solar panels. Scrubbing panels with a rotating-brush system and deionized water is the best way to wash them. Using soap as a cleaning agent can leave a residue that can build up dirt. 

Hiring a solar professional to inspect your panels once a year is important for ensuring their proper operation. After a major storm, such as strong winds or tree damage, an inspection can also be necessary to ensure that your system is operational and safe. Solar inspectors will examine the integrity of the panels, inverter, wires, the main breaker, and the racking equipment. Inspectors will look for loose wires, broken glass, damaged panels, and electrical faults.

Check the positioning of solar panels.

Correct positioning is key for maximum solar production of your solar panels. Shading from nearby trees or a building can impact the efficiency of your solar panels. If you notice a new tree shade before your solar system’s installation, you might need to trim the tree to ensure that you are not losing output.

Keep an eye on output levels.

Many solar installers provide a monitoring system to keep track of your solar production, whether it is an electronic device or an app. A solar monitoring system allows you to have a bird’s eye view of your system’s performance. You can check your system’s energy output and use, optimize energy usage, and receive notifications of any damage to the system. Some solar installers remotely monitor residential solar systems and alert customers of any issues.

When is the right time to replace solar panels?

Replacement of solar panels is necessary only if a system is severely damaged, for example, due to a hurricane. Properly installed solar panels are meant to last for decades. Remember, warranties can cover solar panels and their components if the equipment has inherent defects. Suppose you notice that the output is significantly down after 30 years of owning a solar panel. In that case, you may want to contact a professional solar installer to inspect the system and consult with the installer on the right course of action.

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