Energies, Vol. 18, Pages 4209: Dynamic Comparative Assessment of Long-Term Simulation Strategies for an Off-Grid PV–AEM Electrolyzer System

Energies, Vol. 18, Pages 4209: Dynamic Comparative Assessment of Long-Term Simulation Strategies for an Off-Grid PV–AEM Electrolyzer System

Energies doi: 10.3390/en18154209

Authors:
Roberta Caponi
Domenico Vizza
Claudia Bassano
Luca Del Zotto
Enrico Bocci

Among the various renewable-powered pathways for green hydrogen production, solar photovoltaic (PV) technology represents a particularly promising option due to its environmental sustainability, widespread availability, and declining costs. However, the inherent intermittency of solar irradiance presents operational challenges for electrolyzers, particularly in terms of stability and efficiency. This study presents a MATLAB-based dynamic model of an off-grid, DC-coupled solar PV-Anion Exchange Membrane (AEM) electrolyzer system, with a specific focus on realistically estimating hydrogen output. The model incorporates thermal energy management strategies, including electrolyte pre-heating during startup, and accounts for performance degradation due to load cycling. The model is designed for a comprehensive analysis of hydrogen production by employing a 10-year time series of irradiance and ambient temperature profiles as inputs. The results are compared with two simplified scenarios: one that does not consider the equipment response time to variable supply and another that assumes a fixed start temperature to evaluate their impact on productivity. Furthermore, to limit the effects of degradation, the algorithm has been modified to allow the non-sequential activation of the stacks, resulting in an improvement of the single stack efficiency over the lifetime and a slight increase in overall hydrogen production.