Technical and economic feasibility assessment of hybrid renewable energy system at Kenyan institutional building: A case study

Abstract

This study focused on the technical and economic feasibility assessment of hybrid renewable energy system for powering institutional building in Kenya – a case study of the School of Engineering, University of Nairobi. The study aimed to determine the optimum hybrid renewable energy system that can supply reliable and affordable power to the school. The load profile of the site was determined using power and energy logger (PEL) with data analysis carried out in DataView™ software. The total energy demand and consumption of the establishment were found to be 84.59 kW and 1172 kWh/day, respectively. Grid/wind/photovoltaic/diesel/battery/converter configuration was simulated and optimized in HOMERTM Pro microgrid analysis tool using local meteorological data. The total net present cost was calculated for 25 years to find the lowest cost of energy for the systems. Grid/Photovoltaic/Diesel was found as the optimum system configuration with the system having Cost of Energy (COE) of Ksh 7.89, Net Present Cost (NPC) of Ksh 69,512,100.00, Initial capital cost of Ksh 30,264,100.00, a renewable fraction of 71.6%, simple payback period of six years, discounted payback period of eight years, present worth of Ksh 12,819,300.00, annual worth of Ksh 965,700.00, excess electricity generation of 2.48% etcetera. This result shows that the system is technically and economically viable. The system proved to have reduced the power purchase from the grid by approximately 77% and reduce the electricity bill by approximately 84%. In addition, nine (9) sensitivity cases were used for sensitivity analysis and the result gave the same configuration except in cases where the sizes and prices of some components were changed.