Degradation rate of solar panels

Adrienne SorensenAugust 2, 2018 1001 0

Degradation rate of solar panels 

Solar energy is all about kWh. Overtime more people invest in solar energy because they trust in a future where they self-produce the electricity. A customer buys the promise of future kWh. We’ll review the results of two decades module lifespan. So in order to shed some lights on this topic, we’ll discuss  the analysis of several modules installed almost ten years ago.

Solar modules performance after 9 years in operation

Customer satisfaction of their solar panels are explained by two factors;  maintaining their physical integrity thus shouldn’t fail due to one of their components and  producing the maximum of kWh when their panels are in tact.

Independent studies results 

Various independent studies tackled the question of solar modules degradation end up with an average of -0.8% per year. With an average of -3.5% after 9 years, the degradation of the 16 modules tested would translate into an annual degradation of less than -0.4%. Overall the results are consistent with the feedback from customers and low claim rate in order to deliver a high level of product quality.

The most important factor for  solar panels to work properly is not having internal defect . This is a very important point to underline and have an international certification like the IEC 61215. It ensures solar modules aren’t subject to infant mortality (4 to 5 years). So for the remaining 20 years, it’s about  commitment of the manufacturer towards quality. There’s a cost pressure and a complexity in the supply chain of parts and OEM modules that the quality suffers. It’s proof that the price isn’t the sole in the PV industry for durable and reliable solar panels. 

The degradation of solar panels encourages PV professional to share key messages; 
-Simulation doesn’t override reality when simulating PV plants performances. Real world data displays the need for an investor to choose the right module. 
-Datasheets doesn’t predict  yields, thats indicative and static information. But real life is dynamic and what matters most is how solar modules are designed. Assessing differences simulated sometimes doesn’t consider risks factors. 

If you want to move into the future and join the solar revolution, or if you want to find out what solar panels are right for you, go to and try our price checker tool. You can see how much a system will cost, and how much you can save over the next 20 years. For more information relating to going solar, don't forget to visit our solar blog section for more handy guides and articles.

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