This paper compares the performances of seven different cantilever designs (straight beam, straight-tapered beam, T beam, U beam, V beam, V-T beam and Y beam) to be employed as a piezoelectric energy harvester. All cantilever structures employs the same materials i.e. Aluminium Nitride as piezo layer, Cubic Silicon Carbide as structural layer and Molybdenum as proof mass and electrical electrodes. We use the same thicknesses for these layers for all structures. Their performances are compared in term of resonant frequency, maximum displacement, open-circuit voltage and stress. The results reveal that V-T shaped cantilever beam energy harvester emerges as the overall winner.