Grid-interactive micro-hydrokinetic with pumped-hydro storage: The case study of three South African demand sectors

Abstract

This paper investigates the operation of different demand sector such as residential, commercial and industrial load profiles when supplied with a grid tied micro-hydrokinetic pumped-hydro storage (MHK-PHS) hybrid system. The aim is to explore the demand sector which is more favorable to the proposed grid-tied MHK-PHS hybrid system under the time-of-use (TOU) tariff scheme. Hence, the optimum configuration of the proposed MHK-PHS hybrid system is determined in order to investigate the effect of each demand sector on sizing and operation of the hybrid system. HOMER Pro Version 3.6.1 has been used to perform the optimization under TOU tariff scheme. The results have shown that the industrial load sector incur the lowest cost of energy at the highest capital cost as opposed to the residential and commercial load sectors. However, from economic perspective, the residential demand sector proved to be more favorable to the proposed hybrid system due to the lowest net present cost (NPV). For each load demand sector, HOMER led to oversizing constraint of the hybrid system by not recharging the storage system after use.