Conceptions of a future hydrogen economy have undergone a significant evolution over the past 50+ years. This study identifies three distinct ‘Waves’, or periods of high expectations for a hydrogen economy. The First and Second Waves were followed by declining optimism; the Third Wave is ongoing today. The three Waves are analyzed through a multi-method literature review, and we specifically analyze the First Wave through key historical sources and contextual analysis. We argue that the hydrogen economy emerged in the 1970s as a techno-utopian narrative within the scientific community, where hydrogen was envisioned as the ultimate energy carrier, driven by nuclear energy. Characteristics of the techno-utopian narrative include utopian terminology, dystopian future images, and neglect of negative side effects. During this period, the hydrogen economy did not develop beyond the conceptual phase. The Second Wave, starting in the mid-1990s, witnessed a resurgence of interest in hydrogen, particularly in the mobility sector. Governmental support and media portrayal fueled public enthusiasm, but practical challenges and misleading information resulted in disillusionment with the hydrogen economy ideal by the late 2000s. Today, in the Third Wave, hydrogen is repositioned as an energy vector for a more sustainable future, primarily as a carrier of (variable) renewable energy sources. Lessons from earlier Waves emphasize the importance of affordable renewable energy for hydrogen production, realistic objectives, a developed hydrogen infrastructure, and cross-sector collaboration. By addressing these elements, the Third Wave can avoid past pitfalls and advance hydrogen's role in a sustainable energy future.

Ambitious offshore wind energy targets in the North Sea necessitate innovative solutions for efficiently delivering energy to onshore demand locations. Wind-to-hydrogen systems offer a promising pathway, with three archetypes of system configurations: centralized onshore electrolysis (C-ON), centralized offshore electrolysis (C-OFF), and decentralized offshore electrolysis at each wind turbine (D-OFF). This study introduces a high-resolution, time-dependent simulation framework capable of analyzing offshore wind-to-hydrogen systems with a focus on operational dynamics and comprehensive cost estimation. The framework enables detailed analysis of D-OFF, capturing its unique dynamics driven by direct connections to individual wind turbines, including the impacts of dynamic operation. A comprehensive system analysis, spanning from the wind farm to the hydrogen offtaker, reveals a wide cost range, with Levelized Cost of Hydrogen (LCOHs) ranging from 3.0 to 10.5€/kgH₂ post 2030. Among the different scenarios analyzed, C-OFF with proton exchange membrane electrolysis achieves the lowest LCOHs due to a reduced need for offshore electrical infrastructure, economies of scale, and efficient dynamic operating characteristics. D-OFF with alkaline electrolysis incurs the highest costs and faces operational challenges, such as electrolyzers shutting down when they occasionally fail to reach the minimum load thresholds, lowering hydrogen production. We illustrate the trade-offs between system configurations’ cost, production rate, and electrolyzer stack lifetime across configurations. Insights from this study can be utilized as a starting point for informed decision-making for large-scale wind-to-hydrogen deployment in the Dutch North Sea region.

Hydrogen is deemed necessary for the realization of a sustainable society, especially when renewable energy is used to generate hydrogen. As most of the photon-driven hydrogen production methods are not commercially available yet, this study has investigated the techno-economic and overall performance of four different solar-to-hydrogen methods and photovoltaics-based electrolysis methods in the Netherlands. It was found that the photovoltaics-based electrolysis is the cheapest option with production cost of 9.31 $/kgH2. Production cost based on photo-catalytic water splitting, direct bio-photolysis, and photoelectrochemical water splitting are found to be 18.32 $/kgH2, 18.45 $/kgH2, and 18.98 $/kgH2, respectively. These costs are expected to drop significantly in the future. Direct bio-photolysis (potential cost of 3.10 $/kgH2) and photo-catalytic water splitting (3.12 $/kgH2) may become cheaper than photovoltaics-based electrolysis. Based on preferences of three fictional technology investors, i.e. a short-term, a green and a visionary investor, the overall performance of these methods are determined. Photovoltaics-based electrolysis is the most ideal option, with photoelectrochemical water splitting a complementary option. While photovoltaics-based electrolysis has an advantage on the short-term because it is a non-integrated energy system, on the long-term this might lead to relatively higher cost and performance limitations. Photochemical water splitting are integrated energy systems and have an advantage on the long-term because they need a relatively low theoretical overpotential and benefit from increasing temperatures. Both methods show performance improvements by the use of quantum dots. Bio-photolysis can be self-sustaining and can use wastewater to produce hydrogen but sudden temperature changes could lead to performance decrease.