Publications

Within the framework of “dual carbon” intending to enhance the use of green energies and minimize the emissions of carbon from energy systems this study suggests a cost-effective low-carbon scheduling model that accounts for stepwise carbon trading for an integrated electricity heat gas cooling and hydrogen energy system. Firstly given the clean and low-carbon attributes of hydrogen energy a refined two-step operational framework for electricity-to-gas conversion is proposed. Building upon this foundation a hydrogen fuel cell is integrated to formulate a multi-energy complementary coupling network. Second a phased carbon trading approach is established to further explore the mechanism’s carbon footprint potential. And then an environmentally conscious and economically viable power dispatch model is developed to minimize total operating costs while maintaining ecological sustainability. This objective optimization framework is effectively implemented and solved using the CPLEX solver. Through a comparative analysis involving multiple case studies the findings demonstrate that integrating electrichydrogen coupling with phased carbon trading effectively enhances wind and solar energy utilization rates. This approach concurrently reduces the system’s carbon emissions by 34.4% and lowers operating costs by 58.6%.

Hydrogen-based steelmaking using green hydrogen can achieve above 95 % CO2 emission reductions. Low-cost renewable electricity is a prerequisite and research has found that access to renewable energy resources could pull energy-intensive industry to new locations the “renewables pull”-effect. However previous studies on hydrogen-based steel differ on key assumptions and analyse a wide range of energy costs (10–105 EUR/MWh) making conclusions hard to compare. In this paper we assess techno-economic and strategic drivers for and against such a pull-effect by calculating the levelized cost of green hydrogen-based steel across five archetypical new value chain configurations. We find that the strength of the pull-effect is sensitive to assumptions and that the cost of hydrogen-based steel vary across geographies and value chain configurations to a similar degree as conventional steel. Other geographically varying factors such as labour costs can be as important for relocation and introducing globally varying cost of capital moderates the effect. The renewables pull effect can enable faster access to low-cost renewables and export of green iron ore is an important option to consider. However it is not clear how strong a driver the pull-effect will actually be compared to other factors and polices implemented for strategic reasons. A modest “strategic push“ implemented through various subsidies such as lowering the cost of hydrogen or capital will reduce the pull-effect. In addition focusing on the renewables pull effect as enabling condition risk slowing innovation and upscaling by 2030 in line with climate goals which is currently initiated in higher cost regions.

This study focuses on arguably the most contentious choice of energy supply option available for decarbonizing general-purpose long-haul road freight: hydrogen. For operators infrastructure providers energy providers and vehicle manufacturers to make the investments necessary to enable this transition it is essential to evaluate the feasibility of individual energy supply choices. A literature review is conducted identifying ten requirements for an energy supply choice to be feasible which are then translated into “what would need to be true” conditions for hydrogen to meet these requirements. Considering these evidence from literature is used to assess the likelihood of each condition becoming true within the lifespan of a vehicle bought today. It is concluded that it is unlikely that hydrogen will become feasible in this time frame meaning it can be disregarded as a current vehicle purchase consideration as it will not undermine the competitiveness or resale value of a vehicle using a different energy source bought today. There are two principal innovations in the study approach: the consideration of socio-technical and political as well as techno-economic factors; and the application of realist retroductive option assessment. While not necessary to address the research question regarding hydrogen a realist retroductive assessment is also presented for other prominent low carbon energy source options: battery electric electric road systems (ERS) and biofuels; and the conditions under which these options could be feasible are considered.

Presented is an evaluation of the carbon footprint and costs associated with hydrogen production via the aluminum-water reaction (AWR) identifying an optimized scenario that achieves 1.45 kgCO2 equiv per kg of hydrogen produced. U.S.-based data are used to compare results with conventional production methods and to assess hydrogen use in fuel-cell passenger vehicles. In the optimized scenario major contributors include the use of recycled aluminum (0.38 kgCO2 equiv) aluminum processing (0.45 kgCO2 equiv) and alloy activator recovery (0.57 kgCO2 equiv). A cost analysis estimates hydrogen production at $9.2/kg when using scrap aluminum alloy recovery and recycling thermal energy aligning with current green hydrogen prices. Reselling reaction byproducts such as boehmite could generate revenue 5.6 times greater than input costs enhancing economic feasibility. The cradle-to-grave assessment suggests that aluminum fuel as an energy carrier for hydrogen distribution and fuel cell vehicle applications offers a low-emission and economically viable pathway for clean energy deployment.

Hydrogen use is increasing in transportation including within the railway sector. In collaboration with a governmental institution in the Netherlands we study how to design an efficient hydrogen fueling infrastructure for a railway system. The problem involves selecting yards in a network for hydrogen fueling assigning trains to these yards locating hydrogen storage and fueling stations and connecting them via pipelines. This key planning phase must avoid oversizing costly fueling infrastructure while accounting for track availability at yards and costs due to fueling operations. We formulate this novel problem which has the structure of a nested facility location problem as a mixed-integer linear program to minimize total annualized investment and operational costs. Due to the complexity of real-sized instances we propose a matheuristic that estimates the infrastructural costs for each yard and train assignment by combining a constructive algorithm with a set covering model. It then solves a single-stage facility location problem to select yards and assign trains followed by a yard-level improvement phase. Numerical experiments on a real Dutch case show that our approach delivers high-quality solutions quickly and offer insights into the optimal infrastructure design depending on the discretization of yard areas number of trains and other parameters.

This study examines the economic and regulatory implications of the development of Germany’s hydrogen core network. Using a mathematical-economic model of the amortization account and a reproduction of the network topology based on the German transmission system operators’ draft proposals the analysis evaluates the impact of delaying the network expansion with completion postponed from 2032 to 2037. The proposed phased approach prioritizes geographically clustered regions and ensures sufficient demand alignment during each expansion stage. The results demonstrate that strategic adjustments to the network size and timing significantly enhance cost-efficiency. In the initially reduced and delayed scenario uncapped network tariffs remain below €15/ kWh/h/a suggesting that under specific conditions the amortization account may become redundant while maintaining supply security and supporting the market ramp-up of hydrogen. These findings highlight the potential for demand-driven phased hydrogen infrastructure development to reduce financial burdens and foster a sustainable transition to a hydrogen-based energy system.

Fuel cell (FC) technologies are often regarded as a sustainable alternative to conventional combustion-based energy systems due to their low environmental impact and high efficiency. Thorough environmental assessments using Life Cycle Assessment (LCA) methodologies are needed to understand and mitigate their impacts. However there has been a lack of comprehensive reviews on LCA studies across all major types of FCs. This study reviews and synthesizes results from 44 peer-reviewed LCA studies from 2015 to 2024 covering six major FC types: alkaline (AFC) direct methanol (DMFC) molten carbonate (MCFC) proton- exchange membrane (PEMFC) solid oxide (SOFC) and phosphoric acid (PAFC). The review provides an updated overview of LCA practices and results over the past decade while identifying methodological inconsistencies and gaps. PEMFCs are the most frequently assessed FC typology covering 49 % of the studies followed by SOFCs at 38 % with no studies on DMFCs. Only 11 % of comparative studies carry out inter-comparison between FC types. Discrepancies in system boundary definitions across studies are identified highlighting the need for standardization to enhance comparability between studies. Global Warming Potential (GWP) evaluated in 100 % of the studies is the most assessed impact category. Fuel supply in the use phase a major contributor to greenhouse gas (GHG) emissions is under-assessed as it is usually aggregated with Operation and Maintenance (O&M) phase instead of discussed separately. GWP of energy production by all FC typologies spans from 0.026 to 1.76 kg CO₂-equivalent per kWh. Insufficient quantitative data for a meta-analysis and limited inter-comparability across FC types are noted as critical gaps. The study highlights the need for future research and policies focusing on green hydrogen supply and circular economy practices to improve FC sustainability.

This work studies the feasibility of integrating a hydrogen-powered propulsion system in a regional aircraft at the conceptual design level. The developed system consists of fuel cells which will be studied at three technological levels and batteries also studied for four hybridization factors (X = 0 0.05 0.10 0.20). Hydrogen can absorb great thermal loads since it is stored in the tank at cryogenic temperatures and is used as fuel in the fuel cells at around 80 ◦C. Taking advantage of this characteristic two thermal management system (TMS) architectures were developed to ensure the proper functioning of the aircraft during the designated mission: A1 which includes a vapor compression system (VCS) and A2 which omits it for a simpler design. The models were developed in MATLAB® and consist of different components and technologies commonly used in such systems. The analysis reveals that A2 due to the exclusion of the VCS outperformed A1 in weight (10–23% reduction) energy consumption and drag. A1’s TMS required significantly more energy due to the VCS compressor. Hybridization with batteries increased system weight substantially (up to 37% in A2) and had a greater impact on energy consumption in A2 due to additional fan work. Hydrogen’s heat sink capacity remained underutilized and the hydrogen tank was deemed suitable for a non-integral fuselage design. A2 had the lowest emissions (10–20% lower than A1 for X = 0) but hybridization negated these benefits significantly increasing emissions in pessimistic scenarios.

Water electrolysis for hydrogen production has garnered significant attention in the context of increasing global energy demands and the “dual-carbon” strategy. However practical implementation is hindered by challenges such as high overpotentials high catalysts costs and insufficient catalytic activity. In this study three mono and bimetallic metal−organic framework (MOFs)-derived electrocatalysts Fe-MOFs Fe/Co-MOFs and Fe/Mn-MOFs were synthesized via a one-step hydrothermal method using nitroterephthalic acid (NO2-BDC) as the ligand and NN-dimethylacetamide (DMA) as the solvent. Electrochemical tests demonstrated that the Fe/Mn-MOFs catalyst exhibited superior performance achieving an overpotential of 232.8 mV and a Tafel slope of 59.6 mV·dec−1 alongside the largest electrochemical active surface area (ECSA). In contrast Fe/Co-MOFs displayed moderate catalytic activity while Fe-MOFs exhibited the lowest efficiency. Stability tests revealed that Fe/Mn-MOFs retained 92.3% of its initial current density after 50 h of continuous operation highlighting its excellent durability for the oxygen evolution reaction (OER). These findings emphasize the enhanced catalytic performance of bimetallic MOFs compared to monometallic counterparts and provide valuable insights for the development of high-efficiency MOF-based electrocatalysts for sustainable hydrogen production.