U.S. Department of Energy SunShot Initiative awarded a US$1.35 million funding for UL (Underwriters Laboratories) to develop new scientific methods for predicting PV module material performance and reliability over time. In partnership with several research companies and institutions, this project seeks to provide data on polymeric backsheets that correlates long-term field reliability with accelerated laboratory testing.

Degraded backsheet impacts the long-term performance and reliability of PV modules installed. The backsheet is a thin multilayer plastic sheet that covers the back of a module, protecting people from the high voltage and the other parts inside the panel from damaging ultraviolet light and the elements. Polymeric backsheets play a critical role in maintaining a PV module's performance over an extended outdoor lifetime, and they help ensure electrical insulation safety. However, the quality of current PV backsheet is not reliable enough because of the pressure on keeping costs down, while the long-term durability in actual installed environmental conditions is unclear due to insufficient testing methods.

The SunShot Initiative Award funds laboratory for accelerating testing correlated to actual backsheet degradation in fielded PV modules. The results will benefit module manufacturers to optimize design strategies. Additionally, the results of this project will enable deeper understanding of the reliability of backsheets and will reduce the uncertainty of PV module reliability predictions, making it of great value to owners, operators and insurers of PV power plants.

Ken Boyce, principal engineer manager, Energy & Power Technologies at UL, states, "This project will examine the correlation between data in the laboratory and data that's collected from modules in the field. This will provide some missing links so that realistic models can be built to better predict lifetime performance."

UL’s partners are: 3M Company, Arkema Inc., Case Western Reserve University, the National Renewable Energy Laboratory (NREL), the National Institute of Standards and Technology (NIST), and Northeastern University.

The award was announced at the Solar Power International 2015 tradeshow.

(Photo Credit: UL)