Conceptual Evaluation of a Small-Scale Gravity-Based Pumped Hydro Storage System with Permanent Magnet Generators (PMG) for Rural Renewable Energy Stabilization in Nigeria
DOI:
https://doi.org/10.70882/josrar.2026.v3i2.163Keywords:
PMG, Gravity, Sustainability, Micro-hydro, Off-gridAbstract
Intermittency remains a critical bottleneck for renewable energy adoption in developing regions, as supply fluctuations disrupt grid stability. This study evaluates a hybrid energy system designed to improve power delivery continuity by integrating gravity-fed energy storage (GES) with high-efficiency recovery mechanisms. To address the cradle-to-grave challenges of chemical batteries, a mechanical-hydraulic synergy was modeled to capture surplus energy and convert it into gravitational potential. The system's operational logic utilizes surplus power to drive a hydraulic pump, lifting water to an elevated reservoir; during periods of low supply, this water descends to drive a micro-hydro turbine integrated with a Permanent Magnet Generator (PMG) for electrical conversion. The research utilized a configuration consisting of an elevated water tower (10–20 meters), a micro-hydro recovery unit, and precision instrumentation including flow meters and pressure sensors to track energy movement. Performance was mathematically modeled using gravitational energy equations and verified through semi-urban wind-yield simulations, with the recovery subsystem demonstrating a modeled round-trip efficiency in the range of 72–81%. Results suggest that the hybrid approach could potentially achieve substantially higher reliability compared to standalone intermittent systems, which exhibited approximately 45% reliability under equivalent conditions. The system's projected 50-year service life and favorable levelized cost of storage relative to lithium-ion alternatives further support its viability. This battery-free design represents a potentially scalable, low-maintenance pathway toward rural electrification, offering meaningful mechanical inertia to help stabilize weak-grid infrastructure while mitigating the environmental risks associated with electrochemical disposal.
References
Chaturvedi, D. K., Yadav, S., Srivastava, T., & Kumari, T. (2020). Electricity storage system: A gravity battery. 2020 Fourth World Conference on Smart Trends in Systems, Security and Sustainability (WorldS4), 412–416. https://doi.org/10.1109/worlds450073.2020.9210321
Díaz-González, F., Sumper, A., Gomis-Bellmunt, O., & Villafáfila-Robles, R. (2023). A review of energy storage technologies for renewable energy integration: Grid inertia and frequency stability considerations. Applied Energy, 341, 121056. https://doi.org/10.1016/j.apenergy.2023.121056 .
Hunt, J. D., Zakeri, B., Lopes, R., Barbosa, P. S. F., Nascimento, A., de Castro, N. J., Brandão, R., Schneider, P. S., & Wada, Y. (2021). Life-cycle assessment of gravity energy storage systems for large-scale application. Journal of Energy Storage, 39, 102601. https://doi.org/10.1016/j.est.2021.102601
International Hydropower Association (IHA). (2024). World Hydropower Outlook 2024. London: IHA. Retrieved from https://www.hydropower.org/publications/world-hydropower-outlook-2024
Kougias, I., Szabó, S., Monforti-Ferrario, F., & Moya, A. (2023). The role of hydropower storage in supporting renewable energy integration: A review of pumped hydro storage applications. Renewable and Sustainable Energy Reviews, 173, 113073. https://doi.org/10.1016/j.rser.2022.113073
Kropotin, P. (2023). Gravity energy storage systems with weight lifting. THERMOPEDIA. https://doi.org/10.1615/thermopedia.010359
Ngoma, D. H., Masenga, B., & Petro, L. (2025). Optimization of excess energy storage from an islanding micro-hydropower system as an alternative to dump loads. Discover Energy, 5(3), Article 3. Springer Nature. https://doi.org/10.1007/s43937-024-00003-7
Pius Sarmeje, C., Medugu, D. W., & Danladi, A. (2025). Optimization and integration of vertical axis wind turbines in hybrid renewable energy systems: A systematic review. FUDMA Journal of Sciences, 9(12), 171–177. https://doi.org/10.33003/fjs-2025-0912-4065
Ruoso, A. C., Caetano, N. R., & Rocha, L. A. O. (2019). Storage gravitational energy for small scale industrial and residential applications. Inventions, 4(4), 64. https://doi.org/10.3390/inventions4040064
Smutný, M., Gugushvili, T., & Musil, M. (2023). Guidelines on environmental impact assessment of hydropower projects. United Nations Economic Commission for Europe (UNECE). Retrieved from https://unece.org/environmental-impact-assessment-hydropower
Swe, W. (2018). Application of pumped hydroelectric energy storage for photovoltaic based rural electrification. ResearchGate. https://doi.org/10.13140/RG.2.2.34844.95368
Tao, R., Song, X., & Ye, C. (2022). Pumped storage technology, reversible pump turbines and their importance in power grids. Water, 14(21), 3569. https://doi.org/10.3390/w14213569.
Vincent, S. A., Tahiru, A., Lawal, R. O., Aralu, C. E., & Okikiola, A. Q. (2024). Hybrid renewable energy systems for rural electrification in developing countries: Assessing feasibility, efficiency, and socioeconomic impact. World Journal of Advanced Research and Reviews, 24(2), 2190–2204. https://doi.org/10.30574/wjarr.2024.24.2.3515.
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Copyright (c) 2026 Bashar S. Qasim, Yusuf M. Ahijjo, Muazu Musa, Sadiya Umar, Samira A. Hassan, Muhammad B. Abdullahi, Tinke I. Peni (Author)
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