MO.3.B || Prospective Life Cycle Sustainability Assessment of Energy Technologies

Puig-Samper, Gonzalo; Iribarren, Diego; Dufour, Javier

Within the current context of transition to a sustainable energy system, hydrogen is expected to play a major role. However, this requires moving away from conventional hydrogen production by steam reforming of natural gas. In particular, electrochemical technologies are often envisaged as key hydrogen-production solutions in energy planning studies for countries such as Spain. Different levels of maturity are associated with these technologies depending on the specific solution under consideration. For instance, solid oxide electrolysis cells (SOEC) are expected to reach maturity by 2030, which suggests the suitability of prospective life cycle assessment (LCA) when it comes to evaluating their environmental performance. This work addresses a prospective LCA of hydrogen produced by a 3.4 MW planar SOEC system working at the thermoneutral point in steady-state conditions. The expected evolution of key aspects was considered: lifetime, current density, and degradation. The plant involves a hydrogen production capacity of 2.11 t/day. At the start of operation, the SOEC plant has an electricity consumption of 37.6 kWh/kg H2, in agreement with Hydrogen Europe projections for 2030. Electricity and heat were assumed to be generated in a concentrated solar power plant. Among the indicators calculated, a carbon footprint around 2 kg CO2 eq/kg H2 was estimated. Electricity production was identified as an environmental hotspot. The results suggest a favourable carbon footprint performance when compared to that estimated for conventional hydrogen and hydrogen from grid power electrolysis in 2030, and close to current values for nuclear-based electrolysis. Acknowledgements: This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under Grant Agreement No 101007163. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation programme, Hydrogen Europe and Hydrogen Europe Research.