An optimal dispatch model of renewable generation and pumped hydro energy storage for green hydrogen production

Abstract

The aim of the work is to propose an optimal dispatch model for a pumped hydro energy storage (PHES) system integrated with a photovoltaic plant, wind farm, and grid connection to meet weekly green hydrogen production demand through electrolysis while maximizing operating profit. A mixed-integer nonlinear programming (MINLP) model is formulated to optimize the technical and economic management of the proposed system. The model is applied to a project under development in Spain. The optimization model is solved using GAMS (General Algebraic Modeling System) software and the SCIP solver with a spatial branch-and-cut algorithm. The results from electricity market price scenarios for 2023 and 2030 show that the combined optimal operating model, RE-PHES-ELY, managed energy efficiently. Energy was imported at prices of up to 116 €/MWh when renewable energy was insufficient. Furthermore, exporting at prices of up to 151 €/MWh, maximizing profits during periods of high renewable generation. Pumping reached up to 454 MWh at 67 €/MWh, taking advantage of surplus renewable energy and low prices. Turbining reached up to 385 MWh at 173 €/MWh during periods of renewable shortages. Electrolyzers adjusted their demand to optimize production and profitability. In the 2030 scenario, the increased spread enhances the use of PHES by 117 %, thereby strengthening the economic viability of storage solutions.