The reliability of energy supply to institutional facilities in Nigeria has remained constrained by inadequate grid availability and continued dependence on diesel generation. In this study, the electrical demand characteristics and techno-economic performance of a grid-connected hybrid renewable energy system was evaluated using measured load data and HOMER Pro simulation. An energy audit was conducted to establish the hourly electricity demand profile. Furthermore, site-specific solar and meteorological data were incorporated into the simulation. The measured load profile showed an average demand of 632.17 kW, a peak demand of 987.40 kW and an estimated annual electricity consumption of approximately 5.54 GWh. The techno-economic assessment revealed that PV–battery–diesel–grid configuration is the most favourable system. Simulation results showed that PV generation supplied the dominant share of energy whereas battery storage provided energy balancing with the diesel generator operating intermittently as a backup source. The economic assessment showed a substantial reduction in cumulative cost compared with the base-case electricity supply. The hybrid system reached approximately US$1.7 million over 25 years compared with about US$6.6 million for the base case. The findings demonstrate that integrating PV generation and battery storage with existing grid and diesel infrastructure can substantially reduce conventional energy dependence while improving the economic performance and reliability of electricity supply.

Keywords: photovoltaic system, battery storage, diesel generator, hybrid renewable energy system, HOMER Pro, techno-economic assessment.