Optimal Power Dispatch of a Grid-Connected Photovoltaic with Groundwater Pumped-Hydro Storage System Supplying a Farmhouse

In developing countries, electricity supply remains a challenge for commercial farmers. This is due to their geographical location or distance with reference to the grid. However, renewable energy sources may be a great alternative for onsite electricity generation. Underground pumped-hydro system is a promising innovation technology with power generation potential for remote located farms, with adequate availability of underground water resource. This paper proposes an optimal energy management model of a grid-connected solar photovoltaic (PV) underground pumped-hydro storage (UPHS) system, for commercial farming in arid areas. The model allows the optimal utilization of the proposed PV-UPHS through open wells (borehole). The objective is to reduce the grid electricity cost for farming activities under variable time-of-use (TOU) electricity prices. The optimization problem is solved using Linprog solver as available in the MATLAB toolbox. Based on the results, the proposed PV-UPHS system is effective in minimizing the grid consumption costs by 32.4 percent during high demand winter season. Hence, more savings may be achieved during summer season due to higher solar resource, low grid energy cost as well as low load demand.