Modelling and optimisation studies for generator dispatch strategies for deployment of an off-grid micro-grid in South Africa

This paper presents the modelling of an off-grid micro-grid situated in a remote rural village in Eastern Cape province in South Africa. The modelling looks at the optimization studies to control dispatch strategies for the integration of wind power into the existing micro-grid which comprises an electric load supplied by photovoltaic power, battery bank for energy storage and a diesel generator. The optimization studies are performed using HOMER Pro (R) and aims to identify the best possible dispatch strategy for the dispatchable generation Le. (diesel generator and battery storage) that minimizes load shedding and excess energy production in a system where the all the generation has been sized already. Four dispatch strategies built into HOMER Pro (R), namely Cycle Charging, Load Following, Combined Dispatch and HOMER Predictive Strategy are tested. The aim of this paper is therefore to test and find which of the above dispatch strategies is the best fit for the rural village. Once the best-fit strategy has been determined, it is further customised and optimised for the rural village load profile.