Optimal Sizing and Techno-Economic Analysis of a Stand-alone Photovoltaic – Wind Hybrid System: A Case Study of Busitema Health Centre III in Busia District, Eastern Uganda

Abstract

The total power generation in Uganda stands at 1,777 MW which is below phase two target of 2,325 MW of the National Development Plan (NDP II). To achieve the NDP II target while ensuring sustainable development, requires the utilization of renewable energy particularly solar photovoltaic (PV). Although photovoltaic technology in Uganda is relatively expensive due to high upfront cost, the need to diversify the energy mix of the country thereby enhancing security of supply is necessary, and forms the subject of this study. Uganda is endowed with solar energy resource which can be used to generate electricity for isolated sites in rural areas, and can be combined with the other available resources in the country in the form of hybrid renewable energy systems. Eastern Uganda possesses minimal level of global solar irradiance (GHI) for PV deployment, and approximately 5.15 kWh/m2/day. This study deals with the optimal sizing and techno-economic analysis of PV/Wind hybrid system for Busitema Health Centre III. The load demand for the health Centre was 3.979 kWh. The meteorological data used in this study was obtained from the National Meteorological Centre. The Net Present Cost (NPC), as well as energy output and Levelized Cost of Electricity (LCOE) of the optimal system was determined through simulations using HOMER PRO x 643.13.2 software. For the design of an optimal system, various combinations were obtained with solar PV, wind turbines, batteries, converters and diesel generator from the HOMER optimization simulations. The sensitivity analysis revealed that as electricity price increases, the NPC and LCOE increases for optimal system. The NPC also increases with an increase in the electrical load demand due to the need for expansion of the system. The results show that a solar PV-diesel hybrid system having configuration of 15.75 kW Solar PV, 10 kW diesel generator, and 9 batteries, with a renewable energy fraction of 85.5% solar, and a total electrical energy output of 26,231kWh/yr, gives the optimal configuration. The system had a NPC of $22,427 with LCOE of $0.256/kWh. It was recommended that future research be considered in extending such work to other similar potential sites. Overall, this study revealed that location at coordinates of 0°28'01.0"N and 4°05'24.0"E is preferable for the PV deployment and a hybrid power system can optimally serve Busitema Health Centre III.