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Forecasting Glass Resilience of Large-Format Photovoltaic Modules

DuraMAT will assess the implications of large-format photovoltaic (PV) module designs on module resilience by establishing the necessary framework and tools to predict the probability of glass fracture and avoid glass breakage in modern PV module designs.

The International Technology Roadmap for Photovoltaic estimates that 75% of all installed utility-scale PV modules will be larger than 2.5 m2 and more than 15% will be larger than 3 m2 by 2026. The increasing module size allows for high-power modules but necessitates design changes in module architecture, mounting configuration, and utilized materials. For example, manufacturers use thinner glass front sheets to accommodate any weight increases from size changes or architecture changes as glass/glass designs for bifacial cells. However, thinner glass sheets cannot be heat-treated the same way as thicker sheets, often necessitating a change from tempered to heat-strengthened glass.

Without proper design changes and insufficient mounting configurations, larger modules may become more compliant, leading to larger deflections and possible glass fracture under severe weather events or even spontaneously. Fractured glass sheets represent an electrical safety hazard that causes power loss when the inverter shuts down for safety reasons, which requires the replacement of modules before the anticipated end-of-life.

Core Objective

Disruptive Acceleration Science


National Renewable Energy Laboratory (NREL)


The conducted research will inform the development of glass resilience forecasting model. The model will establish scaling relationships between module design parameters and module size to the probability of glass fracture. The completed framework will enable confident forecasting of glass breakage in modules of any size, in any mounting condition, and under any loading condition, based only on simple laboratory testing of a few samples under uniform load.


Available to NREL scientists, external collaborators, and the public.

We will upload FAIR-compliant data of the experimental fracture mechanics campaign to the DuraMAT Data Hub. Such a data set will contain all necessary parameters to characterize a Weibull distribution as characteristic strength and modulus. Those parameters will be provided for baseline measurement configuration and will allow other researchers and engineers to perform fracture mechanics assessments on their designs.

Further, we will upload all input parameters for the simulated scenarios to the DuraMAT Data Hub. The numerical model results will be post-processed into CSV files for subsequent analysis. Such result files will include information about module deflection, maximum first principal stresses in the glass sheets, and the probability of glass fracture under the simulated mounting and loading configuration.


To learn more about this project, contact Martin Springer.

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