Modelling and simulation of a photovoltaic pumping system with hydraulic storage and energy recovery

This paper presents the development of a discrete-time integrated model of a photovoltaic- powered water pumping system with hydraulic storage and auxiliary energy recovery. The proposed framework couples electrical power balance with hydraulic feasibility constraints in a modular Simulink environment. The system includes a photovoltaic generator, a pump with minimum operating threshold and power limits, a geometrically realistic two-cylinder storage tank, an irrigation subsystem with minimum pressure requirement, and a micro-turbine for auxiliary energy recovery during gravitational discharge. The model enables simultaneous evaluation of PV utilization, tank dynamics, irrigation duration, energy deficit, and curtailment. Simulation results demonstrate the buffering effect of hydraulic storage between variable solar production and irrigation demand. The automatic irrigation stop logic ensures physically consistent operation based on delivered volume, tank depletion, and pressure constraints. The auxiliary micro-turbine contributes measurable energy recovery during irrigation events, reducing net energy deficit and improving system autonomy. The proposed modelling approach provides a practical tool for sizing and scenario analysis of PV–pumping–storage irrigation systems and supports optimization of renewable energy utilization in agricultural applications.