Future clean hydrogen potential from surplus energy: A techno-economic analysis

Hydrogen is increasingly recognized as a pivotal energy carrier in the global transition to- ward net-zero emissions, particularly in hard-to-decarbonize sectors such as industry and transportation. This thesis presents a comprehensive analysis of low-carbon hydrogen production pathways, focusing on electrolysis and thermochemical cycles. Special em- phasis is placed on the Copper-Chlorine (Cu-Cl) thermochemical cycle and electrolyzer technologies, examining their integration with renewable and nuclear energy systems. The electrolysis pathway is assessed by evaluating alkaline, PEM, and solid oxide elec- trolyzers in terms of energy efficiency, technological maturity, and compatibility with intermittent renewable sources. A dedicated analysis investigates the global hydrogen pro- duction potential from surplus solar, wind, and nuclear energy over the period 2023–2050. Focusing on the years 2023, 2030, and 2050, the study models hydrogen output, elec- trolyzer capital costs, and hydrogen prices under both 100% and 50% surplus utilization scenarios, accounting for a 2% annual inflation rate. Results suggest that hydrogen pro- duction from surplus energy could reach a cumulative 6000 Mt by 2050, with production costs falling below USD 2/kg H2. Additionally, the analysis estimates the CO2 emission reductions achievable through the replacement of fossil fuels in electricity generation. Parallel to this, the Cu-Cl thermochemical cycle is examined for its long-term potential in large-scale hydrogen generation, particularly when coupled with waste heat from Su- percritical Water Reactors (SCWRs). The study assesses hydrogen production from the five-step Cu-Cl cycle from 2030 to 2050, using projected learning curves and inflation- adjusted cost models. Scenarios of 100% and 50% SCWR waste heat utilization are analyzed, indicating a possible cumulative output of 270 Mt by 2050, with hydrogen costs approaching USD 2/kg H2. A comparative analysis with electrolyzers is included, consid- ering specific energy consumption, efficiency, and costs. The potential for CO2 emissions reduction through thermochemical hydrogen substitution is also explored. The findings underscore that, while electrolyzers are more commercially advanced today, thermochemical cycles, particularly the Cu-Cl cycle, could play a critical role in future large-scale applications. A hybrid strategy that combines both technologies, supported by sector coupling and forward-looking policies, is likely essential to meet global hydrogen demand and achieve climate goals by mid-century.