Here, we present a collective prospective application that includes electrocaloric effect, thermal energy harvesting and energy storage density in Eu3+ and Nb5+ co-substituted Na0.5Bi0.5TiO3 ceramics. To understand the structural property impact on desired properties, here presented the clear phase evaluation quantitatively with different phase coexistence over structural ambiguity of duel structural phase models. The induced adiabatic temperature change (AT) of these specimens reflects the significant change in entropy(AS) over a wide temperature range. The obtained change in AT evaluated @ 60 kV/cm was found to be nearly 0.4 K for these specimens. The pyroelectric energy harvesting property was investigated in detail with the help of the Olsen cycle. The estimated energy storage density as well as efficiency was enhanced greatly with substitution of Nb concentration as Wrec = 1.58 J/cm(3) and eta = 95(%) for NBET-Nb2 ceramics. The materials with multiple functionalities are considered to be an open window in the field of electronic devices, optoelectronics and solid state refrigerator applications.