SPLTRAK Abstract Submission
Assessment of mechanical robustness of conventional and CFRP-based lightweight PV module architectures under static loads
Umang Desai1,2& Aparna Singh2
1Department of metallurgical engineering and materials science, Indian Institute of Technology Bombay, Mumbai, India
/2National centre for photovoltaic research and education, Indian Institute of Technology Bombay, Mumbai, India

       The conventional terrestrial photovoltaic (PV) modules have an architecture of glass/ethylene vinyl acetate (EVA)/Si-cell/EVA/backsheet. While glass is an essential component for the mechanical stiffness of a PV module, it makes the structure bulky owing to its high density (~2500 kg/m2). Therefore, the bulky conventional design is not ideal for building-integrated PV (BIPV) applications requiring rugged mechanical mounting. Installation of multiple modules on a fragile and old structure may also become challenging. To overcome these limitations of the PV modules' conventional architecture, the lightweight design has recently gained the focus of the PV community.
        This work presents the results of finite element (FE) simulations for the deformation and stresses generated in the solar cells in the conventional and lightweight PV modules­ due to the application of static loads. The lightweight structure presented in this work has the architecture of transparent backsheet (TBS)/EVA/Si-cell/EVA/CFRP/EVA/polyvinyl fluoride (PVF) backsheet (BS) while, model that represents the conventional design has layers of glass/EVA/Si-cell/EVA/BS. The FE simulations are done such that the frame of the modules are held fixed and a uniform load of 2400 Pa and self-weight is applied from the TBS or glass side. It has been observed that due to the application of this static load, the maximum displacement in the conventional and lightweight design is 19.5 mm and 35.4 mm, respectively. Furthermore, the maximum principal stress in the solar cells for the lightweight design is 121 MPa, which is less than the value of maximum principal stress of 133 MPa for the conventional design. The maximum stresses are generated in the cells which are close to the longer edge of the module for the lightweight design while for the conventional design, the most heavily stressed cells are found at the centre of the module.
          The results presented here indicate that the lightweight design has better performance than the conventional design when both the self-weight and static load of 2400 Pa are applied. The maximum stresses generated in both the designs described in this work are well below the fracture strength of silicon cell which is about 200 MPa. Therefore, it can be argued that the lightweight design will be able to sustain the self-weight and static load of 2400 Pa, which simulates wind load in the field.