 This study proposes a CO2-free diabetic compressed air energy storage, CAES, system that uses green hydrogen produced on site by a proton exchange membrane electrolyzer powered by a photovoltaic power plant and compares its energy consumption in CO2 emissions with natural gas-fueled CAES. The results show that the proposed hydrogen-fueled CAES can effectively match the generation profile and yearly production of the natural gas-fueled plant while producing zero CO2 emissions. This article was authored by Luca Miliari, Davide Micheletto, and Daniele Coco.