a vanadium fuel cell system that uses carbohydrates (such as sugar and tapioca) to generate electricity at an already proven conversion efficiency of 45%. The vanadium fuel cell system consists of (l) a vanadium redox flow battery, (2) a catalyic reactor where sugar (or any carbohydrate) is oxidized while the negative electrolyte of the battery is reduced, and (3) another catalytic reactor where oxygen (pure or in air) is reduced and the positive electrolyte of the battery is oxidized.