Why does the efficiency of a solar panel decrease during its lifetime?


Any solar panel sees its efficiency drop during its lifetime.

The value of this performance, after 25 years of use of the panel, is also widely shared by the manufacturers, in the form of a performance guarantee that can be found in the technical data sheets.

You can find the technical sheets of our Dualsun panels in our resource area.


What is it due to? 

Also called “rate of degradation”, all solar panels experience a loss of nominal power over the years.

Current technologies employed in the production of solar panels make this degradation inevitable.

This normal phenomenon of aging is mainly due to the significant exposure of the panels and the thermal and mechanical stresses on the solar panel components.

For modern technologies, this degradation is less than 1%/year (Source).

However, the rate drop can be improved and its impact slowed, depending on the technology of the modules.

At Dualsun, we guarantee the photovoltaic performance of the SPRING 425 Shingle Black panel for 25 years, at 84.8% of the basic linear power.

This corresponds to a loss of about 0.6% per year. We are very proud to offer you high-performance panels!

Find all our guarantees here.


To go further 

The loss is not perfectly linear.

It is common to consider, during the first year of operation, a degradation rate of around 1 to 2.5%.

 This is mainly due to light-induced degradation, also called LID phenomenon(Light Induced Degradation).

 This phenomenon, known in the industry for more than 20 years, manifests itself from the first hours of exposure of the panels to sunlight, due to the traces of oxygen present in the silicon wafer.


Do you want to install solar panels?

To make your project a reality, create it on our study platform MyDualsun.

In less than 7 minutes, you will have your simulation of electricity production, hot water, possible savings, and if you wish, you can be put in touch with a partner installer.