ORCID
https://orcid.org/0000-0001-5559-2136
Abstract
Many renewable energy sources such hydropower—particularly small-scale run-of-river and micro-hydro—offers reliable, low-cost generation. However, their inherent intermittency (due to seasonal flow variations) and inability to instantly match demand necessitate integrated energy storage to ensure a stable, continuous power supply. This review synthesizes contemporary energy storage technologies in the context of their integration with off-grid hydro energy system design.
The study examine a spectrum of storage solutions, evaluating their technical characteristics, costs, and suitability for hybrid hydro applications. Pumped Hydro Storage (PHS), while highly efficient and large-scale, is often geographically constrained and capital-intensive for small off-grid projects. Battery Energy Storage Systems (BESS), especially lithium-ion, provide modular, rapid-response storage ideal for smoothing short-term fluctuations and managing daily load shifts; their declining costs make them increasingly viable. Flow batteries offer advantages in cycle life and scalability for medium-term storage. Hydrogen storage (via electrolysis and fuel cells) presents a promising long-term or seasonal storage option, converting surplus hydro energy into hydrogen for dry-season regeneration, albeit at lower round-trip efficiency.
The core of the review focuses on system design principles for off-grid hydro-storage hybrids. Key considerations include: resource assessment, sizing methodology to optimize the storage capacity and turbine rating, power electronics for seamless integration, and control strategies to dispatch energy efficiently.
In conclusion, no single storage technology is universally optimal. Instead, a hierarchical or hybrid storage approach—combining, for example, a BESS for power quality and a hydrogen subsystem for seasonal arbitrage—often yields the most robust and cost-effective design
Recommended Citation
Ngoma, D. H., & Masenga, B. L. (2026). A review of energy storage technologies with hydro energy system design for off-grid electricity. Tanzania Journal of Engineering and Technology, 45(1), 51-59. https://doi.org/https://doi.org/10.65085/2619-8789.1007
Publisher Name
University of Dar es Salaam
Included in
Electro-Mechanical Systems Commons, Energy Systems Commons, Other Mechanical Engineering Commons, Systems Engineering Commons