Why are solar panel failures rising so fast?

With countries around the world focused on diversifying their energy mix, and with prices for solar panels at record lows, global demand for PV continues to climb.

But with the tides of incentives rising and falling at different times in different countries, it’s still a turbulent, competitive and cost-sensitive environment.

With or without incentives, solar remains a considerable investment. Calculating the true price of solar electricity requires an accurate measure of value in which all the costs of energy production are spread across the system’s expected lifetime (typically 25 years) and assessed on a cost-per-kWh basis. This metric provides an understanding of a system’s true value over time — the levelised cost of electricity (LCoE). LCoE = Capital Expense + Operational Expense ÷ Lifetime Power Output.

It makes sense: a solar panel that lasts longer is more cost-effective. LCoE would more than double by reducing a system’s lifetime to ten years from 25. Industry economics require continuous improvement, and we must pay attention to quality and durability to maximise system lifetimes and returns.

Studies are revealing the industry’s growing pains. TÜV Rheinland, a leading testing authority, recently revealed that the percentage of defective modules has increased by 2.5 times in the past two years.

Ultimately, warranties are hard to track and rarely claimed, and in many cases system owners can only watch as their hard-earned, eagerly awaited investment requires replacement long before expectations.

But doing some homework to identify proven, trusted materials, manufacturers, installers and system owners can mitigate risk more effectively.

Here’s a key example. Of the components that make up a typical solar panel, one of the most critical to longevity is the backsheet, an otherwise nondescript plastic film that undergirds and protects all the other components against the elements. The backsheet is a panel’s first line of defence. Many different backsheet materials are available at many different prices. If the backsheet is compromised, power production can fade faster than it should or suddenly cease altogether, which can double operational expense. Electrical safety can even be compromised.

A five-year field study by DuPont that surveyed fields worldwide representing 1.5 million solar panels reveals that 30% showed yellowing and cracking of the backsheet in as little as two years. The study highlighted a significant performance advantage for panels constructed using polyvinyl fluoride film-based backsheets. Materials matter.

On the cost-control front, the backsheet makes up just 10% of the cost of a panel, so even a relatively small cost increase for materials proven to deliver long-term value will have little impact on the price of the panel. Saving on the backsheet is like skipping oil changes on the family car, only to have to replace the motor well before its time. Penny wise can be pound foolish.

As the solar industry matures and evolves, it is vital to learn as we grow. By seeking out new data, understanding more about how modules and materials degrade, and making informed decisions about key system elements, we can specify component materials that are proven to stand the test of time.

We can choose panels from manufacturers with established quality controls and find experienced installers that know how to do the job right. These are all essential to making solar a safe, rewarding experience, at precisely the time we should be doing everything we can to ensure more people choose solar and that they love the experience. 

Bob Olsen is director of corporate marketing at DuPont Photovoltaic Solutions

This piece was published as part of the Thought Leaders series. Recharge’s Thought Leaders Club brings together leading thinkers and participants from the renewable-energy sector to examine the key challenges facing our industry