Techno-economic analysis of a hybrid system to power a mine in an off-grid area in Ghana

In spite of the abundance of renewable energy and its potential application to mining industries, Ghana has not seen much investment in this area. The provision of electricity for mining activities in Ghana is cost intensive, especially in remote areas that are not connected to utility-grids. In this study, a technical and economic analysis of a hybrid electric power system for an off-grid mine company was conducted. Three different hybrid systems, together with a "Generator only" system as base case were analysed using HOMER software, to select the optimum energy system. The selected system consists of 50 MW of Solar PV, 15 MW of fuel cell system, 600 batteries, 20.5 MW of converter and 20 MW of diesel generator. The system produces 152.99 GWh of electric energy annually. The PV array produces 44%, the fuel cell produces 40% and the diesel produces 14%. At the current cost of system components, and based on assumptions adopted in this study, the optimal system yields a cost of energy of US$0.25/kW and a least cost of energy of US$0.22/kWh, at a diesel price of US$0.80/litre and 30% reduction in both PV module and fuel cell system costs.