Quantifying Emissions and Costs of Geologic Hydrogen: An Integrated Lifecycle Emissions and Techno-economic Approach

Abstract

In the pursuit of sustainable energy solutions, this thesis explores the lifecycle emissions and economic feasibility of geologic hydrogen production. This research extends Brandt's 2023 study of 'prospective' lifecycle assessment (LCA), enhancing the underlying open-source LCA model used in this work and adding a preliminary techno-economic analysis (TEA). The findings demonstrate that geologic hydrogen developments should have emissions intensities that compare favourably to all other hydrogen production pathways. The value of lifetime emissions intensity for Brandt’s Baseline case is estimated at 0.40 kgCO2e/kgH2, representing an increase of ~6% over Brandt’s estimation. The study also highlights the potential for geologic hydrogen to achieve competitive levelized costs (estimated at $1.45/kg), making it a promising candidate in the hydrogen economy. It finds that to achieve the best possible emissions and economic results, proponents of geologic hydrogen developments should seek to maximise the productivity of each well. It also studies the impact of the United States regime of production tax credits for hydrogen, finding that the fivefold increase in the magnitude of credits for meeting employment conditions is generally more impactful than lowering emissions intensity. The thesis underscores the importance of continued refinement of LCA and TEA models to understand geologic hydrogen resources better and ensure they are developed appropriately.