In this study, we investigate the effect of two polymer encapsulation with different material properties such as Youngï¿½s modulus (E), yield strength etc...on the residual stress gradients of silicon. We observe through synchrotron X-ray microdiffraction that, solar photovoltaic (PV) module laminated with encapsulants A and B which have Youngï¿½s modulus of 6.34 and 28.32MPa respectively, reveals distinct variations in residual stress of silicon. The residual stress of silicon near the solder (stress concentration region), showed a maximum quantitative value of ~300 MPa with encapsulant A whereas for the solar PV with encapsulant B, it showed a much higher value of ~450 MPa. Further, this residual mechanical stress and its relation to fracture/crack initiation events of silicon were understood using three point bending tests. The result shows that with encapsulant A, crack initiation of silicon at force of 37KN is observed whereas for the PV with encapsulant B, silicon cracked at much lower force of 10KN. These studies confirm that encapsulant materials have a significant effect on the residual stress of silicon which directly affects the working efficiency and reliability of the solar PV.