ASSESSMENT OF SMALL HYDRO AND SOLAR HYBRID ENERGY SYSTEM FOR RURAL ELECTRIFICATION IN KABALA, SIERRA LEONE

Abstract

The scarcity and rising fossil fuel prices coupled with the harmful emissions is causing rural electrification highly unsustainable and economically unviable. To reduce the over dependency on the fossil fuels that are limited and exhaustible in nature, and ensure sustainable economic growth, it is prudent to use renewable energy resources. Also, for a developing country like Sierra Leone with current electrification rate of 15% to meet the “Access to Affordable, Reliable, Sustainable and Modern Energy for All” sustainable development goal of UNDP 2030 agenda in the face of limited and exhaustible fossil fuels, it needs to harness its abundant renewable energy resources as alternative sources. Two of the main alternative sources of energy in the country to achieve such a goal and also reducing greenhouse emission are solar power and small hydropower, which can be designed as a hybrid system. This dissertation presents the methodology for assessing the potential and effective design of a stand-alone small hydro and solar hybrid renewable energy system for rural electrification. Using HOMER software, assessed a case study for the feasibility of a hybrid renewable energy system in Kabala community, Northern Sierra Leone. The pre-HOMER analysis was done to obtain the community load profile, the hydro and solar renewable energy potentials as input data into the software. The hybrid system was simulated to find the most cost-effective configuration for the system based on the total net present cost (NPC) and the cost of energy (COE). The area has an annual average solar radiation of 5.34kWh/m2/day and design flow of 4720 L/s from the data collected from the NASA website and Ministry of Water Resources respectively. The result proposed a small hydro-solar energy configuration with a total NPC of $5,087,620.00 and COE of $0.106/kWh as the most cost-effective feasible system. This revealed that the integrated renewable energy system would be a cost-effective and feasible option for Kabala case study for rural electrification in Sierra Leone. Furthermore, the sensitivity analysis indicated that the flow rate, nominal discount rate, annual maximum capacity shortage, and daily average load have a sharp impact on the COE.