Project Name: Reliability Evaluation of Bifacial and Monofacial Glass/Glass Modules with EVA and Non-EVA Encapsulants
Funding Opportunity: Solar Energy Technologies Office Fiscal Year 2018 Funding Program (SETO FY2018)
SETO Research Area: Photovoltaics
Location: Tempe, Arizona
SETO Award Amount: $1.3 million
Awardee Cost Share: $375,000
Principal Investigator: Govindasamy Tamizhmani

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

Modules that have solar cells encased in glass on both sides, known as glass/glass modules, are often considered more durable than other types of encasings, but there’s uncertainty of this. Additionally, the most common type of material used in the encapsulated solar cell, ethylene vinyl acetate (EVA), may contribute to faster module degradation. This project team will evaluate the reliability of glass/glass modules with EVA and non-EVA solar cell encapsulants, and glass/glass modules compared with modules with glass in the front and a non-glass backsheet, to determine the most cost-effective options for long-lasting laminates.


The research team will evaluate new solar modules and modules that have been aged outdoors to find out what makes them degrade. They will use accelerated testing in the lab to degrade the material faster and evaluate the modules’ expected reliability by comparing to experiments from outdoor exposure. These tests will be performed on several types of modules: glass/glass and glass/backsheet modules; monofacial, or single-sided, and bifacial, or double-sided, modules; and modules that contain EVA and non-EVA encapsulated solar cells. Through this testing, the team will develop tests that can be used to predict failure or degradation in new systems.


The durability of glass/glass modules has not been thoroughly tested, and there are some indications that EVA in encased solar cells contributes to their degradation. This project will use module data from both accelerated testing and field testing to determine the reliability of EVA and non-EVA encapsulated solar cells, and of glass/glass compared with glass/backsheet modules. This testing will inform future mitigation methods in module degradation.