Project Name: Toward 50-Year Lifetime PV Modules: Double Glass vs. Glass/Backsheet
Funding Opportunity: Solar Energy Technologies Office Fiscal Year 2018 Funding Program (SETO FY2018)
SETO Research Area: Photovoltaics
Location: Cleveland, OH
SETO Award Amount: $1,400,000
Awardee Cost Share: $340,000
Principal Investigator: Roger French

-- Award and cost share amounts are subject to change pending negotiations --

The goal of this project is to measure the degradation rates of standard crystallized silicon solar cells in different conditions and determine which conditions lead to the lowest degradation rate. The team expects that this work will decrease efficiency degradation rates to 0.2% per year, from the current average of 0.5% per year.


To determine the rate and possible causes of solar cell degradation, the researchers will build both monofacial, or single-sided, and bifacial, or double-sided, solar modules. While both types of cells have a glass front side, the researchers will experiment with glass as well a transparent plastic on the back side of the bifacial modules. The team will expose one set of modules to extreme temperatures and light to speed up degradation in the lab, while a second set will be tested outdoors. The project team will measure the solar cells’ sunlight-to-electricity conversion efficiency, looking for correlations between degradation, encasing material, and the testing conditions to determine whether certain materials or conditions significantly affect the degradation rate.


To determine the best combination of parameters that will lead to longer-lasting solar cells, the project team has proposed a way to both measure and compare degradation rates by correlating results between accelerated and real-time testing and between different solar module materials and architectures. The results from this approach will inform future solar cell designs that would degrade more slowly, thereby decreasing energy costs.