LLNL researcher takes aim at solar-cell reliability

A Lawrence Livermore National Lab engineer has been awarded $570,000 through the Department of Energy SunShot Initiative to explore spectroscopic technology as a means of detecting moisture buildup in solar photovoltaic (PV) cells. 

Over the next two years, Mihail Bora, a Materials Engineering Division (MED) research team member at the Lab, will try to prove that spectral imaging can be used to evaluate the moisture content of PV modules and to create two-dimensional maps and models of water concentration. Bora will then use these results as a screening tool to help protect the modules from water damage. Water ingress can cause corrosion of metal parts, delamination and decrease the efficiency of solar cells.

"Our goal is to measure water content without destroying the photovoltaic modules and to remove uncertainty on how reliable the modules are over their long expected lifetimes," Bora said. "Reliability plays a tremendously important role in making solar competitive with other non-renewable energy sources, because it allows project managers to more efficiently use its funds and may lead to a decrease in financing costs."

Bora’s project builds on the team’s previous testing with laminates and aims to answer questions critical to industry adoption, such as detection range, limits, accuracy and stability. The typical approach to addressing the problem, Bora said, is focused on water transport measurements in polymer membranes or controlled laboratory setups.

This project, Bora said, combines optics and reliability, two areas of core importance to Lawrence Livermore’s mission.

Partners in the research included two solar manufacturers, MiaSolé HiTech Corp. and Prism Solar Technologies Inc.

The SunShot Initiative is a national effort that drives innovation to make solar energy fully cost-competitive with traditional energy sources before the end of the decade. Through SunShot, the Energy Department supports efforts by private companies, universities and national laboratories to drive down the cost of solar electricity to 6 cents per kilowatt-hour.