<p>As global energy demands soar and environmental concerns intensify, effective energy storage solutions are essential to transitioning towards sustainable energy systems. This review explores the landscape of energy storage technologies, examining their roles in mitigating the challenges posed by intermittent renewable sources such as solar and wind power. An in-depth analysis of various storage systems—including mechanical (Pumped Hydro Storage, Compressed Air, and Flywheels), electrochemical (batteries and supercapacitors), chemical (hydrogen storage and synthetic fuels), and thermal (sensible, latent, and thermochemical storage)—highlights their efficiencies, capacities, environmental impacts, and scalability. Each technology’s comparative strengths and limitations are discussed to assess suitability for residential, commercial, and utility-scale applications. Additionally, recent advancements, future research directions and challenges in material innovation, system integration, and policy frameworks are outlined, underscoring the critical role of regulatory support and market mechanisms in driving adoption. By integrating insights from materials science, engineering, economics, and policy, this review provides a comprehensive overview of current and emerging energy storage technologies. This resource serves as a foundation for stakeholders to better understand the multifaceted dimensions of energy storage and to guide future research and innovation for a more sustainable energy future.</p>