Optimisation analysis of a stand-alone hybrid energy system for the senate building, university of Ilorin, Nigeria

Abstract

This study investigates the feasibility of providing electric power from a PV-Wind-Diesel-Battery hybrid system as an alternative energy supply to the Senate Building of the University of Ilorin, Nigeria. The case study presents an average daily energy demand of 1520 kWh, 712.5 kWh and 212.8 kWh during a typical dry season, rainy season and weekend days respectively. The daily average energy demand data is logged using Fluke 432-II Power Quality and Energy Analyzer. The solar irradiance and wind speed data of the site over one year period were sourced from the National Aeronautics and Space Administration (NASA) website. A two-objective optimisation cost function is formulated and solved considering three different scenarios of the case study. Analysis of various system configurations is carried to meet the power demand at the possible minimum cost of energy (COE). The results obtained are compared with that of Hybrid Optimisation Model for Electric Renewable (HOMER) software. Both approaches reveal that PV-Diesel-Battery system configuration yields the optimal results for the case study. Sensitivity analysis is carried out to examine the conditions under which it is technically and economically feasible to include wind turbine in the system design as proposed. However, comparative cost analysis carried out shows that the hybrid energy system with a cost of $0.283/kWh (#84.90/kWh) is not economically viable yet compared with $0.087/kWh (#26.00) currently charged by most electric utilities in Nigeria.