Production & Supply Chain

Hydrogen-based technologies prominently fuel cells are emerging as strategic solutions for decarbonization. They offer an efficient and clean alternative to fossil fuels for electricity generation making a tangible contribution to the European Green Deal climate objectives. The primary issue is the production and transportation of hydrogen. An on-site hydrogen production system that includes CO2 capture could be a viable solution. The proposed power system integrates an internal combustion engine (ICE) with a steam methane reformer (SMR) equipped with a CO2 capture and energy storage system to produce “blue hydrogen”. The hydrogen fuels a high-temperature polymer electrolyte membrane (HTPEM) fuel cell. A battery pack incorporated into the system manages rapid fluctuations in electrical load ensuring stability and continuity of supply and enabling the fuel cell to operate at a fixed point under nominal conditions. This hybrid system utilizes natural gas as its primary source reducing climate-altering emissions and representing an efficient and sustainable solution. The simulation was conducted in two distinct environments: Thermoflex code for the integration of the engine reformer and CO2 capture system; and Matlab/Simulink for fuel cell and battery pack sizing and dynamic system behavior analysis in response to user-demanded load variations with particular attention to energy flow management within the simulated electrical grid. The main results show an overall efficiency of the power system of 39.9% with a 33.5% reduction in CO2 emissions compared to traditional systems based solely on internal combustion engines.

The rapid increase in global warming requires that sustainable energy choices aimed at achieving net-zero greenhouse gas emissions be implemented as soon as possible. This objective emerging from the European Green Deal and the UN Climate Action could be achieved by using clean and efficient energy sources such as hydrogen produced from nuclear power. “Renewable” hydrogen plays a fundamental role in decarbonizing both the energy-intensive industrial and transport sectors while addressing the global increase in energy consumption. In recent years several strategies for hydrogen production have been proposed; however nuclear energy seems to be the most promising for applications that could go beyond the sole production of electricity. In particular nuclear advanced reactors that operate at very high temperatures (VHTR) and are characterized by coolant outlet temperatures ranging between 550 and 1000 ◦C seem the most suitable for this purpose. This paper describes the potential use of nuclear energy in coordinated and coupled configurations to support clean hydrogen production. Operating conditions energy requirements and thermodynamic performance are described. Moreover gaps that require additional technology and regulatory developments are outlined. The intermediate heat exchanger which is the key component for the integration of nuclear hybrid energy systems was studied by varying the thermal power to determine physical parameters needed for the feasibility study. The latter consisting of the comparative cost evaluation of some nuclear hydrogen production methods was carried out using the HEEP code developed by the IAEA. Preliminary results are presented and discussed.

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.

Under the dual pressures of global climate change and energy structure transition the offshore wind–solar–current energy coupling hydrogen production (OCWPHP) system has emerged as a promising integrated energy solution. However its complex multi-energy structure and harsh marine environment introduce systemic risks that are challenging to assess comprehensively using traditional methods. To address this we develop a novel risk assessment framework based on hesitant fuzzy sets (HFS) establishing a multidimensional risk criteria system covering economic technical social political and environmental aspects. A hybrid weighting method integrating AHP entropy weighting and consensus adjustment is proposed to determine expert weights while minimizing risk information loss. Two aggregation operators—AHFOWA and AHFOWG—are applied to enhance uncertainty modeling. A case study of an OCWPHP project in the East China Sea is conducted with the overall risk level assessed as “Medium.” Comparative analysis with the classical Cumulative Prospect Theory (CPT) method shows that our approach yields a risk value of 0.4764 closely aligning with the CPT result of 0.4745 thereby confirming the feasibility and credibility of the proposed framework. This study provides both theoretical support and practical guidance for early-stage risk assessment of OCWPHP projects.

This study aimed to investigate the effectiveness of dark fermentation in biohydrogen production from agro-industrial wastes including apple pomace brewer’s grains molasses and potato powder subjected to different pretreatment methods. The experiments were conducted at a laboratory scale using 1000 cm3 anaerobic reactors at a temperature of 35 ◦C and anaerobic sludge as the inoculum. The highest yield of hydrogen was obtained from pre-treated apple pomace (101 cm3/g VS). Molasses a less complex substrate compared to the other raw materials produced 25% more hydrogen yield following pretreatment. Methanogens are sensitive to high temperatures and low-pH conditions. Nevertheless methane constituted 1–6% of the total biogas under these conditions. The key factor was appropriate treatment of the inoculum to limit competition from methanogens. Increasing the inoculum dose from 150 cm3/dm3 to 250 cm3/dm3 had no further effect on biogas production. The physicochemical parameters and VFA data confirmed the stability and usefulness of activated sludge as a source of microbial cultures for H2 production via dark fermentation.

This study presents a comprehensive optimization of a tri-generation system that integrates dual geothermal wells Liquefied Natural Gas (LNG) cold energy recovery and hydrogen production using an advanced Response Surface Methodology (RSM) approach. The system combines two geothermal wells with different temperature profiles power generation via an Organic Rankine Cycle (ORC) and hydrogen production through a Proton Exchange Membrane (PEM) electrolyzer enhanced by integrated LNG regasification for improved energy recovery. The primary novelty of this work lies in the first application of RSM for multi-objective optimization of geothermal-based tri-generation systems moving beyond the conventional single-objective approaches. A 40-run experimental design is employed to simultaneously optimize three critical performance indicators: exergy efficiency power-specific cost and hydrogen production rate considering six key operating parameters. The RSM framework enables systematic exploration of parameter interactions and delivers statistically validated predictive models offering a robust and computationally efficient optimization strategy. The optimized system achieves outstanding performance with an exergy efficiency of 44.60% a competitive power-specific cost of 19.70 $/GJ and a hydrogen production rate of 5.15 kg/hr. Comparative analysis against prior studies confirms the superiority of the RSM-based approach demonstrating a 1% improvement in exergy efficiency (44.60% vs. 44.16%) a significant 44.1% increase in hydrogen production rate (5.15 kg/hr vs. 3.575 kg/hr) and a 0.81% reduction in power-specific cost compared to genetic algorithm-based optimization.

This study develops a photovoltaic (PV)-based hydrogen production system specifically designed for university campuses which is expected to lead in sustainability efforts. The proposed system aims to meet the electricity demand of a Hydrogen Research Center while supplying energy to an electric charging station and a hydrogen refueling station for battery-electric and fuel-cell electric vehicles operating within the campus. In this integrated system the electricity generation capacity of PV panels installed on the research center’s roof is determined and the surplus electricity after meeting the energy demand is allocated to cover the varying proportions needed for both electric charging station and hydrogen production system. The green hydrogen produced by the system is compressed to 100 350 and 700 bar with intermediate cooling stages where the heat generated at the compressor outlet is absorbed by a cooling fluid and repurposed in a condenser for domestic hot water production. A full thermodynamic analysis of this entirely renewable energy-powered system is conducted by considering a 9-hour daily operational period from 8:00 AM to 5:00 PM. The average incoming solar radiation is determined to be 484.63 W/m2 resulting in an annual electricity generation capacity of 494.86 MWh. Based on the assumptions and data considered the energy and exergy efficiencies of the proposed system are calculated as 17.71 % and 17.01 % respectively with an annual hydrogen production capacity of 3.642 tons. Various parametric studies are performed for varying solar intensity values and PV surface areas to investigate how the overall system capacities and efficiencies are affected. The results show that an integration of hydrogen production systems with solar energy offers significant advantages including mitigating intermittency issues found in standalone renewable systems reducing carbon emissions compared to fossil-based alternatives and enhancing the flexibility of energy systems.

Offshore hydrogen production offers a promising solution for harnessing wind energy far from shore by using hydrogen as an energy carrier instead of electrical cables. Flexibility in hydrogen production systems is crucial to maximising the conversion of intermittent wind energy into hydrogen. To improve the performance of lowpressure compressed gas buffer stores hybrid gas-hydride tanks have been identified as a viable solution increasing useable storage density from 1.2 kg m− 3 to 6.3 kg m− 3 with just a 5 vol% addition of hydride. This study evaluates the reduction in tank volume reduction in cost and enhancements in useable storage density achieved by integrating different hydrides under varying temperature conditions. Using hydrogen mass flow rate profiles a storage mass target was determined for optimisation. The results demonstrate that hybrid gas-hydride tanks can reduce tank size by around 80 % lowering costs by 24 % and achieve a 5.1-fold improvement in useable storage density.

As a pivotal clean energy carrier for achieving carbon neutrality green hydrogen technology has attracted growing global attention. This review systematically examines four mainstream water electrolysis technologies—alkaline electrolysis proton exchange membrane electrolysis solid oxide electrolysis and anion exchange membrane electrolysis—analyzing their fundamental principles material challenges and development trends. It further classifies and compares power electronic converter topologies including non-isolated and isolated DC–DC converters as well as AC–DC converter architectures and summarizes advanced control strategies such as dynamic power regulation and fault-tolerant operation aimed at enhancing system efficiency and stability. A holistic “electrolyzer–power converter–control strategy” integration framework is proposed to provide tailored technological solutions for diverse application scenarios. Finally the challenges and future prospects of green hydrogen across the energy transportation and industrial sectors are discussed underscoring its potential to accelerate the global transition toward a sustainable low-carbon energy system.

The cost reduction of electrolysers is critical for scaling up green hydrogen production and achieving decarbonization targets. This study presents a novel and comprehensive dataset of electrolyser projects in Europe. It includes full cost and capacity details for each project and capturing project-specific characteristics such as technology type location and project type for the period 2005–2030. We apply the learning curve methodology to assess cost reductions across different electrolyser technologies and project sizes. Our findings indicate a significant learning effect for PEM and AEL electrolysers in the last 20 years with learning rates of 32.1% and 22.9% respectively. While AEL cost reductions are primarily driven by scaling effects PEM electrolysers benefit from both technological advancements and economies of scale. Small-scale electrolysers exhibit a stronger learning effect (25%) whereas large-scale projects show no clear cost reductions due to their early stage of deployment. Projections based on our learning rates suggest that reaching Europe’s 2030 target of 40 GW electrolyser capacity would require an estimated total investment of 14 billion EUR. These results align closely with previous studies and such predictions are closed to estimates from other organization. The dataset is publicly available allowing for further analysis and periodic updates to track cost trends.