A Systematic Review of Gravity Energy Storage: Technologies, Modeling, Integration, and Future Perspectives

Gravity energy storage (GES) has emerged as a promising option for medium- to long-duration storage in renewable-dominated power systems. However, the literature remains fragmented across architectures, modeling approaches, and application contexts, hindering systematic comparison and consistent assessment of technological maturity. This paper presents a systematic review of GES conducted in accordance with the PRISMA 2020 guidelines; 107 studies retrieved from 4 databases (Scopus, Web of Science, IEEE Xplore, and ScienceDirect) were analyzed by integrating fundamental principles, system architectures, modeling and control strategies, and techno-economic performance. Unlike previous reviews, this work explicitly links physical principles, design variables, and system-level performance, enabling consistent cross-architecture comparison and clearer positioning of GES within the broader storage landscape. Liquid-based systems and solid gravity energy storage (SGES) architectures, including tower-, shaft-, rail-, mountain-, piston-, and modular-based systems, are compared in terms of scalability, efficiency, response, and infrastructure requirements. Attention is given to the gap between theoretical and real-world performance, highlighting low intrinsic energy density, strong dependence on large-scale infrastructure, the absence of standardized techno-economic assessment, and limited long-term operational data. The review positions GES as a complementary technology rather than a direct competitor to electrochemical or hydro-based storage, and critically examines emerging trends, including hybridization, digitalization, advanced control, and material optimization. Finally, it identifies key technological and deployment gaps and proposes a research roadmap centered on scalability, standardization, and system integration.