Abstract

This paper presents the design and modeling of an off-grid hybrid stand-alone system for fulfilling the load requirements of an off-grid household located in remote Benin City, Edo State in Nigeria. Using a 48 V DC bus, the system was sized using Homer Pro software. Optimization results - which presents various systems’ designs – show that the most cost effective and efficient system is the hybrid system consisting of a 1.23 kW photovoltaic (PV) array, four 12 V batteries, 1.6 kW inverter and a 4.8 kW diesel generator. Moreover, the hybrid system is found to be a better solution in terms of its techno-economic performance compared to the diesel generator only system. Sensitivity analysis is carried out to test the adaptability of the hybrid system to a load variation of 20%, and Solar PV input variation of 10%. Results unveil that the lowest cost investment (i.e., investment in the PV-battery system) may not give the best returns. This supports the selection of the aforesaid hybrid configuration to satisfy the household’s load.

Key words: Stand-alone hybrid system; Photovoltaics; Sensitivity analysis; Homer Pro; System optimization; Economic analysis.