<p>The increasing need to have sustainable and lightweight energy harvesting systems has led to the increasing interest in emergent materials based on natural fibers. This research discussed the effectiveness of natural fiber-reinforced composites as a substrate for piezoelectric vibration energy harvesters. The material modelling approach, representative volume element (RVE) is used to obtain the material properties of the natural fiber composites. Through numerical simulations, a novel E-shaped harvester substrate using natural fiber-reinforced polymer composites with jute/epoxy, flax/epoxy and hybrid is evaluated. Further, the influence of the hybridization ratio (jute and flax) on frequency, strain, and voltage is also analyzed through numerical simulation. Then the effect of multidirectional and cross-ply orientations on the performance improvements in the energy harvester is studied. The findings suggested that the hybrid composites are outperforming the non-hybrids, also, some of the hybrid combinations using cross-ply orientations are producing higher strain than the allowable. In the meantime, the same hybrid combinations using multidirectional-ply orientation are producing adequate strain and voltage. Furthermore, these findings suggest that the flexural stiffness is a more dominant property for sustainable energy harvester designs.</p>