Supercapacitors, celebrated for their high power density and rapid charge-discharge capabilities, represent a promising solution to meet the increasing demand for sustainable energy storage systems. This research adopts a sustainable approach to develop green supercapacitors by leveraging biomass-derived materials for both electrodes and electrolytes, thereby aligning with global efforts toward green energy technologies and the circular economy. Activated carbon was synthesized from pine bark using acid (H₃PO₄), base (K₂CO₃), and salt (ZnCl₂) as activation agents, with activation temperatures varied at 600°C, 800°C, and 1000°C. The resultant activated carbon, with increasing surface area and porosity at higher activation temperatures, served as the active electrode material. Additionally, cellulose nanofiber derived from wood pulp was crosslinked with mobile Cu²⁺ ions to function as the electrolyte. Real supercapacitor devices were fabricated, demonstrating excellent energy and power densities, highlighting the potential of these materials for practical energy storage applications. This research aligns with several principles of green chemistry, including the use of renewable feedstocks (pine bark and wood pulp) and the valorization of waste materials. The integration of bio-derived materials minimizes reliance on non-renewable resources and reduces the environmental footprint of the synthesis process. Future work could explore alternative, less hazardous activation agents or activation methods to enhance the sustainability of the process. Additionally, the recyclability and biodegradability of the resulting supercapacitors should be evaluated to ensure alignment with the principles of design for degradation and waste prevention. This study underscores the role of green chemistry in advancing environmentally friendly energy storage technologies and contributes to the broader transition toward a cleaner and more sustainable energy future.