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How long will solar panels last?

Most solar panels have 25-year performance warranties, but some manufacturers go further and offer three decades.In fact, solar panels last much longer than that. Warranties typically guarantee that the panels will work at 80 percent above their rated efficiency after 25 years. A study by NREL (National Renewable Energy Laboratory) shows that most panels are slightly less efficient after 25 years. It still produces energy.

Investing in solar energy is a long-term, well-rewarded commitment thanks to a relatively long solar panel’s life expectancy. Upfront costs can be high, but over time the investment pays for itself through monthly savings in energy bills.

Often the first question we receive from clients trying to make a solar investment is: “How long will the solar panels last?

25 years of guaranteed operation are just the start

Panels are usually guaranteed for 25 years, so it meets your expectations in terms of time. But in reality, studies have shown that panels continue to operate at low efficiency long after the warranty has expired.An average solar panel’s performance warranty ensures that the modules will produce at least 90% of their rated output in year 10 and at least 80% in year 25 or 30.

Nearly 80 percent of solar panels outlast their warranties, according to NREL research.

Standard solar panel warranty

25(30)-year performance warranty: at least 80% of rated output

The standard warranty for solar panels is 25 years. During this time, the manufacturer guarantees that the panel will operate at or near peak efficiency. Most panels produce at least 80% of their rated output under warranty.

For example, a 300-watt panel should produce at least 240 watts (80% of its rated output) at the end of the 25-year warranty.

Some companies offer 30-year warranties or promise 85% efficiency.

The standard is 25 years with an efficiency of 80%.

10-year product or workmanship warranty: no failures for a decade

Solar panels also have a separate workmanship warranty to cover some manufacturing defects, such as junction box or frame failures. Usually the process warranty is 10 years, some manufacturers offer a 20 year process warranty.It covers the integrity of the panel itself and protects you against defects in material, premature wear and tear, as well as environmental and workmanship issues. The manufacturer may choose to repair or replace the product at their discretion.

Each product of WinSeven Solar provides 12 years of product or workmanship warranty and 25-year performance warranty.Read Solar PV System Design  and follow our step-by-step guide to design a perfect system.A warranty will only remain in force as long as your system is designed appropriately.

PV module output power attenuation：average decay rate of the panels is between 0.5% and 0.8% per year

Decay rate is the rate at which a solar panel loses efficiency over time. According to a 2012 study by the National Renewable Energy Laboratory, the average decay rate for panels is between 0.5% and 0.8% per year.if a panel has a decay rate of 0.8% per year, it will be 8% less efficient after 10 years of operation.

As solar panel technology has advanced over the years, the decay rate of solar panels has continued to increase. Some Tier 1 manufacturers offer degradation rates below 0.5%

The output power attenuation of crystalline silicon photovoltaic modules is divided into three stages:

1. In the first stage, called initial photoinduced attenuation, the output power of the PV module decreases by 1% to 2.5% during the first few days of use, but then levels off.
2. The second stage, called component aging decay, that is, the very slow power decline in long-term use, the main reason is related to the slow decay of the battery, and also related to the performance degradation of the packaging material. Silicon component manufacturers typically offer a 25-year power warranty. The general commitment is that the power at the end of the 10th year shall not be less than 90% of the initial value, and at the end of the 25th year shall not be less than 80% of the initial value.
3. In the third stage, the PID potential can induce decay (the cell discharges the module frame, that is, the packaged photovoltaic module has a weak leakage phenomenon)

What does the lifetime of a solar panel mean for your ROI?

This is good news if your primary concern is getting a positive return on investment (ROI) on your system：Most estimates of distributed PV revenue are based on a 25-year warranty. Any increase in power generation beyond 25 years is a bonus. Most panels will continue to generate electricity at reduced power long after the end of their useful life. That’s because solar panels don’t have any moving parts, so they’re very reliable.

How to extend the service life of  solar panels？

Generally speaking, solar panels are easy to maintain as they are designed to withstand extreme weather conditions and all types of precipitation such as snow, hail and wind. But you can extend their lifespan with simple daily care and quality maintenance.

• Choose a suitable solar panel material, good quality can be used for a long time.
• Work with a trustworthy solar installer that provides routine maintenance checks.They can help you solve some unnecessary troubles.
• Reduce the use in extreme weather, the temperature is too low weather will damage the internal structure of solar panels to a certain extent.
• and wash them with water if they are dirty. When dust or sand isn’t removed for too long, it can cause microcracks and scratches on the solar panel. 
• Keep the surface clean and tidy: Buildup of dirt, pollen, leaves, and guano can affect the efficiency of your solar panels. While rain is usually enough to clean your panels, if you find that your panels aren’t working at full capacity, you may want to consider getting professionally cleaned.
• Since everything is interconnected in your system, Pay attention to other elements of your solar system (inverters, batteries, optimizers, etc.). failure of practically any component might damage the panels.
• don’t have debris or destructive materials on the surface, otherwise it will easily cause scratches and affect the power generation efficiency of solar panels

Solar panels may be the longest-lived part of your solar system. If you want to extend the life of your PV system, you still need to maintain or replace the inverters and batteries to keep everything running properly.