Numerical simulation and experimental comparison of strain measurements within a vertical bifacial photovoltaic noise barrier demonstrator

Abstract

A photovoltaic noise barrier (PVNB) is an example of infrastructure-integrated photovoltaics (IIPV) that serves as a conventional roadside infrastructure element while also generating solar energy. These integrated applications of photovoltaic (PV) modules are particularly relevant in areas where there is limited land area available for the installation of PV plants. Like any engineering structure, a PVNB is influenced by environmental factors such as temperature variations, wind loads and other external stressors. This study focuses on temperature fluctuations and the resulting thermomechanical strains within a PVNB demonstrator in Genk, Belgium. To achieve this, optical fibre Bragg grating (FBG) sensors for temperature and strain monitoring are implemented within the PV modules on the inner surface of the glass cover at three different locations. Both the trend of increases and decreases in monitored temperatures and strains are in good agreement with the data recorded by a nearby meteorological station. Subsequently, numerical simulations are performed and compared with the experimentally measured values, demonstrating a strong correlation with only one stressor input, i.e. the monitored temperature within the PV modules. Furthermore, the influence of using alternative encapsulant materials, such as thermoplastic polyolefin (TPO) or polyvinyl butyral (PVB) instead of the more commonly used ethylene vinyl acetate (EVA), on the strains and stress distributions on the cells is studied. This work proves, therefore, the possibility of real-time monitoring of internal strains within PV-integrated outdoor applications and strengthens the use of numerical simulations in forecasting internal stresses for the use in degradation models.