Energy storage now a days is becoming an imperative part of renewable energy. With the massive growth of renewable energy sources, energy storage can play a substantial role in renewable energy integration in India. It is beneficial for entire supply chain mainly due to enhanced electric power quality, dependability and better grid stability. Thus, lowering renewable energy intermittency, with increased user-friendliness and accessibility of electrical energy in remote places and reduction in harmful emissions. This paper Part-I of two papers primarily presents an overview of the selected energy storage technologies like Pumped hydro energy storage, Compressed air energy storage, Battery energy storage, Flywheel, Supercapacitors, Hydrogen energy storage, Superconducting magnetic energy storage, and Thermal energy storage. It highlights driving factors for growing energy storage in India. A comprehensive comparison of various technical characteristics and features of these technologies is also discussed.