Optimal Development of a Standalone Photovoltaic/Diesel/Battery Hybrid Energy System for Residential and Commercial Buildings.

Abstract

Uganda has an estimated population of 49.8 million, and according to IEA data, around 30% of Ugandans have access to electricity, but only one in seven does in rural areas. Many rural suffer the absence of grid infrastructure. In recent years, the concept of hybrid energy systems (HESs) is drawing more attention for electrification of isolated or energy-deficient areas. When optimally developed, Hybrid energy systems prove to be more reliable and economical than single energy source systems. The aim of this study is to develop an optimal PV/diesel/battery hybrid energy system configuration for remote residential and commercial buildings. HOMER software is used as a tool for optimization analysis by investigating the techno-economic and environmental performance of the proposed system under the LF strategy, CC strategy, and combined dispatch CD strategy. The different system component configurations were compared and analysed to obtain the most suitable combination of the hybrid energy systems so as to mininise costs and CO2 emissions. The simulation results reveal that the CD strategy has a net present cost (NPC) and cost of energy (COE) values of Ush 107M and Ush 522.99/kWh, which are lower than those of systems utilizing the LF and CC strategies for a residential home. On the other hand, simulation results also reveal that the LF strategy has a net present cost (NPC) and cost of energy (COE) values of Ush 3.74B and Ush 518.14/kWh, which are lower than those of systems utilizing the CD and CC strategies for commercial building. From an environmental point of view, the LF strategy offers the best performance, with CO2 emissions of 710 kg/year and 11,269 kg/year for residential and commercial respectively. Moreover, the results show that variations in critical parameters, such as battery minimum state of charge, solar radiation, diesel price, and load growth, exert considerable effects on the performance of the proposed system.