Optimal battery energy storage selection for reliable power supply in grid-constrained rural healthcare facilities

Many rural clinics in Sub-Saharan Africa suffer from erratic national grids, despite the significance of reliable electricity for quality healthcare delivery. This necessitates reliance on expensive and greenhouse gas-emitting diesel generators (DG). Furthermore, a key bottleneck hindering the deployment of long-term electrification solutions is the selection of an appropriate energy storage device coupled to unreliable grids and intermittent renewable energy systems. Therefore, this study addresses this gap by conducting a techno-economic comparative analysis of distinct battery energy storage technologies, namely, nickel-iron (NIB), vanadium redox flow (VRB), lead-acid (LAB), and lithium-ion (LIB), for the sustainable operation of a hybrid power system supplying a rural healthcare centre in Nigeria. The HOMER Pro software tool was employed for the analysis of the hybrid system comprising the grid, solar photovoltaic (PV), and DG. Notable indices used for the analysis included the net present cost (NPC), levelized cost of energy (LCOE), battery autonomy, state of charge, losses, throughput, and emissions. Findings show that the Grid/PV/DG/LAB system is the most economically viable, with the lowest NPC of $101,495.39 and an LCOE of $0.143/kWh. Meanwhile, the Grid/PV/DG/LIB system is superior in technical performance. Thus, with the lowest battery losses of 322 kWh/yr, the system has the highest battery autonomy of 87.6 hours and a renewable fraction of 89.6%. The Grid/PV/DG/VRB and Grid/PV/DG/NIB systems presented intermediate profiles. Therefore, the study concludes that trade-offs between immediate cost (which favours LAB) and long-term performance (which favours LIB) should be considered when selecting an appropriate battery energy storage for sustainable hybrid power system operations.