Abstract: Renewable energy utilization and smart grid is the ultimate goal of power system development, and energy storage technology is the necessary guarantee to achieve the goal. Firstly, according to the existing energy storage technologies, electromagnetic energy storage, mechanical energy storage and chemical energy storage are introduced respectively, and the corresponding technical parameters are compared, and their respective characteristics and application occasions are analyzed; then, from the power supply side, grid side and user side, the typical application scenarios of energy storage are analyzed, and the technical performance requirements of energy storages are elaborated in terms of the peak load shifting and valley filling of power system, smooth grid connection of renewable energy, power frequency regulation, renewable energy consumption and improvement of power quality are expounded. Finally, the prospect of technology system, matching method and life cycle assessment is presented.