Demand of piezoelectric energy harvesting is continuously increasing in general application areas for generating green electricity. This paper presents a multipurpose piezoelectric energy harvester and the studies thereon under two distinct vibration energy source applications: diesel engine and the footsteps of a human being in the motion. Investigations have been made by strategically mounting the piezoelectric elements on the base of a diesel engine to capture and convert mechanical vibrations into electrical energy. A direct correlation was observed between the weight placed over the piezoelectric element and the output voltage, current, as well as the power. As the weight increased, both the current and voltage output from the piezoelectric elements increased. The engine was operating at 1475 rpm. The piezoelectric frame when placed on the engine base under the weight of 18 kg produced electric output voltage, current, and power as 12.98 V, 172 µA, and 2232.56 µW respectively which is significantly high compared to the condition when the piezoelectric frame is placed below the base of the engine frame. The power generated is enough to lighten the small LEDs. The study is further extended to capture energy from footstep pressure. A linear relationship is observed between foot pressure, footstep frequency, and the harvested electric energy. The output voltage, current, and power from piezoelectric harvester placed on vibrating base at 120 footsteps per minute under 16 kg load are 1.98 V, 88 µA, and 174 µW respectively. These findings collectively highlight the versatility and efficiency of piezoelectric energy harvesting system in diverse contexts, offering promising avenues for sustainable energy solutions.