Exploring The Methods and Future Directions of Direct Electrical Energy Storage Systems: A Systematic Review

As global energy systems transition towards greater reliance on renewable energy, the need for efficient energy storage becomes critical for grid stability and power quality. While conventional energy storage systems typically involve mechanical, chemical, or electrochemical conversions which often introduce energy losses and increases system complexity. In contrast, direct electrical energy storage offers an innovative pathway to reduce conversion losses, improve efficiency, and simplify system architectures. This paper provides a systematic review of existing methods for direct electrical energy storage, focusing on supercapacitors (including electrostatic double layer capacitor (EDLC) and pseudocapacitors) and superconducting magnetic energy storage system (SMES). These technologies are analyzed in terms of efficiency, scalability, cost, and practicality. Despite their promising potential, challenges such as high material costs, physical limitations, and integration complexity hinder their widespread adoption. The review identifies critical research gaps and proposes future directions, including advancements in materials science, control systems, and hybrid models, to enable the practical implementation of direct electrical energy storage technologies. This work aims to establish a foundation for advancing direct electrical energy storage and highlights its significance in next-generation power systems.