How long do solar panels last?
In general, the average lifespan of a solar panel is approximately 25 years. However, this does not mean that a solar panel will stop working entirely after a quarter of a century. In reality, solar panels can produce electricity well after 25 years, just at a slowly decreasing rate of efficiency.
Naturally, there are a variety of factors that influence how long and how well a solar panel will produce electricity. In this article, we will illustrate the life of a solar panel by examining common solar degradation and the warranties associated to help guarantee electricity production.
Solar Panel Degradation and Efficiencies
Just like the roof over your head or the car in your driveway, solar panels are an asset that will slowly degrade over time. So despite the little amount of work required to maintain solar panels, if you are planning to utilize solar energy for more than 30 years, your solar panels may need to be replaced in order to sustain the maximum electricity production possible.
According to a study by the National Renewable Energy Laboratory, the median solar degradation rate for modern solar panels is a loss of approximately 0.5% in system efficiency each year. This means that after installation, on average, a solar panel will lose 0.5% of its original efficiency each year. Of course, there is a wide variety of quality and technology available in the solar panel market. The study did find outliers as large as 3% degradation each year, however, in order to best illustrate how long a solar panel will last, we will use the median efficiency loss of 0.5% as an example below.
After experiencing its first year of efficiency loss at 0.5%(often times the first year is more than subsequent years), a solar panel will produce 99.5% of its maximum electricity potential. Calculated at the same rate, the solar panel will still produce well over 80% of its efficiency after 25 years.
To understand what efficiency means in a solar panel, let’s say that in its first year of energy production, your solar panel produces 500 kWh. This means, that at 80% efficiency after 25 years, this same solar panel will still produce 400 kWh over the course of the year! The solar industry has adopted 80% efficiency as the “end of the lifespan” of a solar panel, however in reality a solar panel will last much longer.
Average Solar Panel Warranties
In order to cover the effects of degradation, solar manufacturers will offer performance warranties to guarantee sustained electricity production. The average solar panel performance warranty guarantees 80% of production after 25 years. Following a similar line of degradation, some warranties also include a 90% production guarantee after 10 years of use.
The second kind of solar panel warranty is considered an equipment guarantee. Whereas it is true most solar panel installations go on without a hitch, there are sometimes issues that go awry that can be covered by the equipment warranty. Equipment warranties typically cover 10 years of manufacturing defects, premature wear and tear, as well as environmental impacts like oversized hail or heavy windstorms.
It is important to note that if you are hiring a company to install your solar panels, there may also be a good workmanship warranty that goes along with it. This additional warranty is independent of your solar panels themselves, but would cover construction issues such as damage to a roof.
As solar panel technology continues to innovate and improve, future solar panels may last even longer than they do today. Whereas most solar panels last for 25 years, rated at 80% of system efficiency, it has been reported that some solar panels installed in the 1970’s still operate at 80% efficiency as well. That’s over 40 years of renewable energy! In other cases, spent solar panels are being donated to underserved communities who are still able to benefit from less efficient energy production.We hope this article helped answer some of your questions about the lifespan of solar panels. If you are interested in harnessing the power of the sun for your electricity needs, you can browse our selection of solar panels.