Bending strength evaluation and power generation performance optimization of a curved photovoltaic-thermoelectric hybrid device

Curved photovoltaic-thermoelectric (PV-TE) hybrid devices have great potential applications in the fields of aerospace, navigation and daily life. During the application, the curvature radius of the PV-TE hybrid device needs to be altered to fit different curved surfaces. Naturally, the bending strength of the curved hybrid device is a very important issue. This paper evaluates the bending strength and optimizes the output power and energy conversion efficiency of the curved hybrid device. The stress solutions are obtained by means of the variational principle. The recovery of transverse shear stress is achieved by using the Cauchy's polar equilibrium equation. It is found that the thermal stress is much smaller than the bending stresses induced by the bending deformation of the hybrid device. The circumferential stress is the key factor that results in the failure of the hybrid device. The optimization of the curvature radius of the hybrid device is conducted and the safety region is identified to protect the hybrid device from strength failure. The ratio of thickness to cross-sectional area of the thermoelectric leg is optimized to obtain the optimum power generation performance of the hybrid device. This paper offers some favorable suggestions for structural design of the curved hybrid device.