Optimal energy management and techno-economic assessment of hydrogen energy production system incorporated with photovoltaic and battery storage

Abstract

Green hydrogen (H2) has garnered significant attention in recent years as a key component of a zero-emission future owing to its diverse range of applications. The energy management (EM) strategy of the green H2 production system (HPS) plays a crucial role in facilitating efficient and cost-effective green H2 production. This can be achieved by regulating the operating point of the electrolyzer (EL) to obtain economic and operational benefits. This study proposes an optimal EM scheme for a photovoltaic-based battery (BT) grid-connected green HPS. The HPS is intended to meet H2 and electricity demands of an industrial HPS. The objective of the EM scheme is to minimize the cost of green H2 production by minimizing the total system costs of the HPS, while ensuring that the system operates reliably. The objective is realized by incorporating the EM strategy model with Z-score statistical values of past grid electricity costs, which reflect seasonal electricity price trends. This enables green H2 production when the utility grid electricity prices are relatively low. The EM variables considered for the optimization include: EL status (on/off operation of the EL), electricity purchased from the grid, input power to the EL and output power from EL (H2 production rate), energy stored in the H2 storage tank and BT, discharging and charging power of the BT and H2 tank. Four test case systems (Case #1 - #4) were used to demonstrate the techno-economic benefits of the proposed EM scheme model for green HPS. Finally, a sensitivity analysis is performed on the green HPS to investigate the impact PV power and EL capacity on the cost of H2 and EL efficiency.