Norbornadiene/Quadricyclane (NBD/QC) is a prototypical bridged bicyclic diene (BBD)‐based photoswitch that has been well‐studied for molecular solar thermal energy storage (MOST). Inspired by synthetically accessed BBDs, herein several photoswitches are rationally designed with modulated ring strain energies (RSE) to incorporate high energy storage density (ESD) and storage time in a single couple. The storage energy (〖ΔG〗^str) calculated at DLPNO‐CCSD(T)/Def2TZVP level is correlated with difference in RSE of two isomers whereas thermal back reaction (TBR) barrier calculated at (8,8)‐CASPT2/6‐311++G** shows correlation with RSE in photoproduct. These structure‐property‐RSE relationships illustrates that two photoisomers need not to be highly strained. Instead, the RSE in photoproduct and diene should be minimized while maintaining a large enthalpy difference between them to increase ESD and extend energy storage times in a single photoswitch. Herein, the structural skeletons are explored that holds promise to remarkably improve thermochemical properties relative to the unsubstituted BBD‐based photoswitches reported so far. Photoswitches with short saturated bridge but elongated unsaturated bridge bestow desirable thermochemical parameters and can be regarded as excellent MOST candidates. The work provides guidance to improve thermochemical properties via strain engineering of BBD‐based photoswitches and opens a new avenue for designing and future experimental investigations of MOST systems.