Optimization of Hydrogen systems for prospective Life Cycle Assessment: Well-to-Tank approach

The optimization of hydrogen energy systems generally focuses on minimizing total cost and greenhouse gas (GHG) emissions. While climate neutrality by 2050 is the objective set by the European Green Deal, with a target on GHG emissions, other environmental impacts such as resource demand and land use are also of great importance and are mostly not taken into account in these models. This study uses the Life Cycle Assessment (LCA) method to analyze 18 Key Environmental Indicators (KEI). The framework combines a multi-objective design strategy for hydrogen networks with LCA evaluation. The optimization strategy uses a Mixed Integer Linear Programming (MILP) approach with an augmented epsilon-constraint, implemented in the GAMS environment. The Pareto solutions for hydrogen supply chains obtained from optimization were analyzed using the SimaPro Power user package, the Ecoinvent database, and the ReCiPe2016 method with a Well-to-Tank approach. The results showed that considering only GHG emissions leads to poor results for traditional solutions like SMR, and low performance in other KEIs such as water consumption and mineral resource scarcity for the electrolysis process using PV. These findings emphasize the importance of multi-objective optimization that considers multiple environmental criteria, not just GHG emissions.