Session: 12-01: Hydrogen Energy, Alternative Fuels, Bioenergy, and Biofuels

Paper Number: 138609

138609 - Guidelines for Cost-Optimal Design of Hydrogen Production Systems Through Water Electrolysis: A European-Scale Assessment 

Abstract: 

Hydrogen is expected to play a pivotal role in expediting the transition toward a carbon-neutral future. Nevertheless, hydrogen production is currently largely dependent on fossil sources, whit low-carbon hydrogen accounting for less than 1% of the total. Within this context, a cost-optimal design of renewable power-to-hydrogen (PtH) systems is crucial to achieve competitive costs for the production of green hydrogen and to encourage its diffusion.

In this analysis, PtH systems based on water electrolysis are designed with the objective of reliably meeting a defined hydrogen demand profile while simultaneously minimising the cost of hydrogen production. The model of the PtH system includes photovoltaic (PV) and wind turbines (WT) as renewable generators, a battery storage system, a low-temperature electrolyser, a compressor and a high-pressure hydrogen storage tank. The optimal design problem is tackled using the mixed-integer linear programming (MILP) technique. In this approach, both the sizes of the power-to-hydrogen components and their operation throughout a reference year are imposed as decision variables. A partial-load performance curve for the electrolyser is also implemented in the optimisation framework. This is needed to achieve an accurate representation of the electrolyser operation when powered by variable renewable energy sources.

This study delves into investigating the cost-optimal combination for the sizes of the renewable generators and the electrolyser. The ultimate goal is to provide comprehensive guidelines for industry, policy makers and stakeholders on the optimal design of green hydrogen production systems. Various PtH configurations are explored by changing the typology of renewable generators: PV-only, WT-only and hybrid (i.e., both PV and WT). Additionally, the analysis is expanded to include multiple countries to assess how the availability of wind and solar resources influences the optimal sizes of the PtH components.

Depending on the geographic location, the levelized cost of hydrogen (LCOH) varies across a wind range (spanning from 4 up to 20 €/kg). PV-only systems prove to be a cost-effective solution in locations where the average PV capacity factor exceeds 13%. Below this value, the hydrogen cost sharply increases because of the need for high-capacity hydrogen storage tanks. Compared to PV-only systems, WT-only configurations typically necessitate less oversizing of the electrolyser and hydrogen storage, and result in better exploitation of the local renewable resource. However, a high wind capacity factor is crucial to cope with the current high cost of wind turbine technology. Overall, hybridizing the renewable production emerges as the winning solution for delivering green hydrogen at the lowest cost.

Presenting Author: Paolo Marocco Politecnico di Torino

Presenting Author Biography: Paolo Marocco, Assistant professor at the Energy Department of Politecnico di Torino.
His background is a PhD in Energy Engineering. His main research activities are related to green hydrogen production, storage, and final uses (transport, power and heat generation, industry). Activities range from the experimental testing of electrochemical devices (electrolysers and fuel cells) to energy systems’ modelling (optimal design and operation of complex energy systems).

Authors:

Paolo Marocco Politecnico di Torino
Marta Gandiglio Politecnico di Torino
Massimo Santarelli Politecnico di Torino