Rechargeable energy storage systems are highly demandable in the present scenario. Willing to engineer economical energy storage applications using environmentally sustainable technology, a high-temperature controlled heating process has synthesized activated porous carbon in an inert atmosphere with the bio-waste materials' KOH activation process. X-ray diffraction analysis confirms the phase and field emission scanning electron microscopy characterize the morphological features. Electrochemical studies are evaluated in envisaging the prospective approach of that system in the energy storage devices. This activated porous carbon has a mean pore size of 1.81 nm and a specific area of 811.8 m²g^−1, which is high. The specific capacitance is evaluated to be 565.2 Fg⁻¹. The porous carbon exhibits 98% stability up to 10000 cycles with high specific energy of 21 Whkg⁻¹ at the specific power of 5000 Wkg⁻¹. Assembled solid-state symmetric supercapacitor depicts 96% capacity retention with a high specific energy of 24.5 Whkg⁻¹ at the specific power of 801.82 Wkg⁻¹. The large surface area with porosity that enhanced the amount of charge storage can boost an electrical double-layer capacitor. The high value of specific capacitance and long cycle stability makes it a prospective candidate to attain the urge for the establishment of new functional materials for energy storage.