Chemical energy storage is a vital component of the broader energy sector, encompassing 1. applications across various sectors including renewable. Among these,chemical energy storage (CES) is a more versatile energy storage method,and it covers electrochemical secondary batteries; flow batteries; and chemical,electrochemical,or thermochemical processes based on various fuels such as hydrogen,synthetic natural gas. Energy storage projects belong primarily to the renewable energy sector, specifically within the bro. European Commission's science and knowledge service. It aims to provide evidence-based s. In the context of this report, CEST is defined as energy storage through the conversion of electric ty to hydrogen or other chemicals and synthetic fuels.