A sustainable, eco-friendly, and economical approach to recycling fly ash from power stations that burn heavy oil into sodium vanadate nanostructures. Various nano-shapes of the Na-vanadates were successfully prepared and then elucidated using different characterization techniques. The prepared Na-vanadate (NaV6O15) nanostructures were employed as electrode materials for supercapacitor applications. To evaluate the electrode performance, electrochemical measurements of three nanostructured sodium vanadate electrodes were conducted with cyclic voltammetry (CV) and galvanostatic charging-discharging (GCD) techniques in a 1 M Na2SO4 electrolyte. Among all formulation shapes of the synthesized Na-vanadates, the NaV6O15 with a rod-like structure (NVO-NRs) achieved a remarkable specific capacitance of 410 F/g at 1 A/g. Additionally, it demonstrated an exceptional cycling life with 94% retention over 10000 continuous cycles. The (NVO-NRs) exhibited a superior energy density of 65.9 wh/kg at a power density of 500 w/kg. Overall, the prepared (NVO-NRs) electrode supplies durable, long-lasting, and efficient materials for supercapacitor applications.