Optimal operation scheduling of grid-connected PV with ground pumped hydro storage system for cost reduction in small farming activities

A model of electricity cost minimization is proposed which can be implemented in small farming activities where boreholes are present for water supply. In this case, a hybrid system composed of solar photovoltaic and pico hydro supplied by a pumped storage system are used minimize the electricity cost in a dynamic electricity pricing environment. The varying price of electricity, the load demand, the reservoir state of water stored as well as the solar resource at any instant determine the optimal power flow from the different power sources to the load; these are the control variables to be optimised with the aim of reducing the power consumed from the grid. The optimization problem can be solved using linear programming. The simulation results can be used to investigate the impact and benefit of the proposed model on the electricity cost reduction of small loads in the South African farming sector.