Albin Kasser supported his thesis on June the 23rd 2025 at Paris-Saclay
Abstract
This dissertation investigates the economic competition among green technologies in the context of the energy transition, with a particular focus on low-carbon hydrogen. Beyond the classic “grey-to-green” paradigm that models cleaner technologies replacing fossil-fuel-based alternatives, this work emphasizes the increasingly relevant competition within green technologies. Low-carbon hydrogen provides a particularly illustrative case, as competition arises both internally, between hydrogen-based technologies, and externally, between hydrogen and alternative solutions such as electrification. This competition concerns both production pathways and end-use applications, and reflects either the substitution of carbon-intensive solutions or the allocation of scarce low-carbon resources. The dissertation seeks to understand how policy instruments, induced technological change and uncertainty interact to shape the deployment and allocation of competing low-carbon technologies. It is structured around three core chapters.The first chapter explores the competition between battery-electric and fuel cell buses, using a dynamic optimization model that incorporates learning-by-doing and market segmentation. The analysis shows how a niche market (for example, long-range routes) can sustain the survival of a higher-cost technology that is better suited to that specific segment, such as hydrogen, if it receives early support. The model highlights the importance of timing and deployment scale in shaping long-term outcomes, especially depending on whether technical change is treated as endogenous or exogenous. Learning-by-doing can help alternative technologies overcome early cost barriers if the niche is sufficiently large, but strong learning in other markets, as with batteries, can also allow initially less-suited technologies to capture it.The second chapter develops a framework for allocating limited green hydrogen across competing end-uses to maximize social welfare. It introduces a “hydrogen merit order” that ranks sectors according to both abatement costs and the opportunity cost of abatement. A dynamic model captures how optimal allocation evolves with the carbon price and prioritizes early investment in sectors with high learning potential or limited low-carbon alternatives. Applied to the Marseille-Fos industrial cluster, the analysis highlights the importance of targeting sectors like chemicals and steel to avoid costly misallocation.The third chapter builds a model of competition between two low-carbon technologies under cost uncertainty, firm risk aversion, and information asymmetry between firms and policymakers. It analyzes the design of technology-neutral versus technology-specific support schemes and compares price and quantity policy instruments. The analysis is motivated by debates surrounding the design of carbon contracts for difference that have been proposed to support the deployment of hydrogen in the industry.The model is then applied to low-carbon hydrogen production, comparing water electrolysis and steam methane reforming with carbon capture and storage. It appears that the gains from targeted support increase with technology substitutability but decline as climate ambition rises.This dissertation combines theoretical modeling and numerical simulation to explore key questions in environmental, energy, and innovation economics. While hydrogen serves as the primary empirical case, the insights aim to inform broader governance challenges in managing low-carbon technological competition and designing effective public support mechanisms for the energy transition.
