Transmission, Distribution & Storage

Establishing a climate-neutral energy system is among the most urgent challenges facing humanity with the natural gas network forming a critical component of energy and commodity infrastructure. The hydrogen economy based on climate-neutral hydrogen which serves as both energy source and raw-material for numerous sectors offers a promising pathway for significant reduction in CO2 emissions. However the lack of an extensive hydrogen infrastructure underscores the need for transitional solutions. Given this infrastructure gap and the urgency to establish a reliable and less emission-intensive commodity network methane pyrolysis (MP) emerges as a promising technology for supporting the transition to a climate-neutral energy system. Within this context this study evaluates the intricacies of long-distance pipeline transport of hydrogen (H2) and methane (CH4) focusing on the placement of MP units. The primary goal is to provide “turquoise hydrogen” produced from natural gas via MP along with solid carbon from distant locations to industrial consumers. Two configurations are assessed: Configuration I represents a centralized supply concept transporting molecular hydrogen while Configuration II delivers methane to consumers for on-site hydrogen production. The reference system covers a transport distance of 500 km extending to 4000 km with recompression stations every 125 km. The transport capacity of the hydrogen pipeline is set at 13 GW with the methane mass flow set to match the equivalent hydrogen output chemically bound in methane. A parameter study examines power requirements and global warming impact (GWI) over various transport distances. For distances between 2000 and 4000 km Configuration II requires less power (Δ = 229.4–443.0 MW) and results in GWI savings of 0.25 to 0.37 kgCO2-eq.kgH2−1 owing primarily to the lower specific energy consumption for methane transport compared to hydrogen. The study concludes that the electricity mix of the exporting and importing regions significantly affects the GWI of hydrogen supply with the MP unit contributing a substantial part (6.92 kgCO2-eq.kgH2−1) to the total GWI. The approach of Configuration I is favorable for regions with a low-GWI electricity supply while Configuration II is better suited for regions where the electricity mixes of both the exporting and importing regions are similar.

In 21st century the energy demand has grown incredibly due to globalization human population explosion and growing megacities. This energy demand is being mostly fulfilled by fossil-based sources which are non-renewable and a major cause of global warming. Energy from these fossil-based sources is cheaper however challenges exist in terms of climate change. This makes renewable energy sources more promising and viable for the future. Hydrogen is a promising renewable energy carrier for fulfilling the increasing energy demand due to its high energy density non-toxic and environment friendly characteristics. It is a non-toxic energy carrier as combustion of hydrogen produces water as the byproduct whereas other conventional fuels produce harmful gases and carcinogens. Because of its lighter weight hydrogen leaks are also easily dispersed in the atmosphere. Hydrogen is one of the most abundant elements on Earth yet it is not readily available in nature like other fossil fuels. Hence it is a secondary energy source and hydrogen needs to be produced from water or biomass-based feedstock for it to be considered renewable and sustainable. This paper reviews the renewable hydrogen generation pathways such as water splitting thermochemical conversion of biomass and biological conversion technologies. Purification and storage technologies of hydrogen is also discussed. The paper also discusses the hydrogen economy and future prospects from an Indian context. Hydrogen purification is necessary because of high purity requirements in particular applications like space fuel cells etc. Various applications of hydrogen are also addressed and a cost comparison of various hydrogen generation technologies is also analyzed. In conclusion this study can assist researchers in getting a better grasp of various renewable hydrogen generation pathways it's purification and storage technologies along with applications of hydrogen in understanding the hydrogen economy and its future prospect.

Achieving a net-zero energy system in Europe by 2050 will likely require large-scale deployment of hydrogen and seasonal energy storage to manage variability in renewable supply and demand. This study addresses two key objectives: (1) to develop a modeling framework that integrates seasonal storage into a stochastic multihorizon capacity expansion model explicitly capturing tactical uncertainty across timescales; and (2) to assess the impact of seasonal hydrogen storage on long-term investment decisions in European power and hydrogen infrastructure under three hydrogen demand scenarios. To this end the multi-horizon stochastic programming model EMPIRE is extended with tactical stages within each investment period enabling operational decisions to be modeled as a multi-stage stochastic program. This approach captures short-term uncertainty while preserving long-term investment foresight. Results show that seasonal hydrogen storage considerably enhances system flexibility displacing the need for up to 600 TWh/yr of dispatchable generation in Europe after 2040 and sizing down cross-border hydrogen transmission capacities by up to 12%. Storage investments increase by factors of 5–14 which increases the investments in variable renewables and improve utilization particularly solar. Scenarios with seasonal storage also show up to 6% lower total system costs and more balanced infrastructure deployment across regions. These findings underline the importance of modeling temporal uncertainty and seasonal dynamics in long-term energy system planning.

This review aims to summarize the recent advancements and prevailing challenges within the realm of hydrogen storage and transportation thereby providing guidance and impetus for future research and practical applications in this domain. Through a systematic selection and analysis of the latest literature this study highlights the strengths limitations and technological progress of various hydrogen storage methods including compressed gaseous hydrogen cryogenic liquid hydrogen organic liquid hydrogen and solid material hydrogen storage as well as the feasibility efficiency and infrastructure requirements of different transportation modes such as pipeline road and seaborne transportation. The findings reveal that challenges such as low storage density high costs and inadequate infrastructure persist despite progress in high-pressure storage and cryogenic liquefaction. This review also underscores the potential of emerging technologies and innovative concepts including metal–organic frameworks nanomaterials and underground storage along with the potential synergies with renewable energy integration and hydrogen production facilities. In conclusion interdisciplinary collaboration policy support and ongoing research are essential in harnessing hydrogen’s full potential as a clean energy carrier. This review concludes that research in hydrogen storage and transportation is vital to global energy transformation and climate change mitigation.

Activated carbon as a hydrogen storage material possesses advantages such as low cost high safety lightweight and good cycling performance. Zhundong coal characterized by low calorific value high volatility and elevated reaction activity stands out as an exceptional raw material for the production of activated carbon. This study employed Zhundong coal for the synthesis of hydrogen storage activated carbon exploring the impact of acid treatment and varied activation conditions on Zhundong coal. The specific surface area of sample ZD-HK3-AC is 1980 m2 /g and the gravimetric hydrogen storage density reaches 0.91 wt% under the condition of 80bar at room temperature. The adsorption–desorption isotherms nearly overlapped demonstrating excellent cycling performance and high mechanical strength. At the same time the relationship between the pore structure parameters of activated carbon and hydrogen storage density was explored revealing the mechanism of activated carbon adsorption and hydrogen storage. These findings hold significant guiding implications for the preparation and research of hydrogen storage materials utilizing activated carbon.

Hydrogen is the energy carrier for a sustainable future without fossil fuels. As this requires a reliable transportation infrastructure the conversion of existing natural gas (NG) grids is an essential part of the worldwide individual national hydrogen strategies in addition to newly erected pipelines. In view of the known effect of hydrogen embrittlement the compatibility of the materials already in use (typically low-alloy steels in a wide range of strengths and thicknesses) must be investigated. Initial comprehensive studies on the hydrogen compatibility of pipeline materials indicate that these materials can be used to a certain extent. Nevertheless the material compatibility for hydrogen service is currently of great importance. However pipelines require frequent maintenance and repair work. In some cases it is necessary to carry out welding work on pipelines while they are under pressure e.g. the well-known tapping of NG grids. This in-service welding brings additional challenges for hydrogen operations in terms of additional hydrogen absorption during welding and material compatibility. The challenge can be roughly divided into two parts: (1) the possible austenitization of the inner piping material exposed to hydrogen which can lead to additional hydrogen absorption and (2) the welding itself causes an increased temperature range. Both lead to a significantly increased hydrogen solubility in the respective materials compared to room temperature. In that connection the knowledge on hot tapping on hydrogen pipelines is rare so far due to the missing service experiences. Fundamental experimental investigations are required to investigate the possible transferability of the state-of-the-art concepts from NG to hydrogen pipeline grids. This is necessary to ensure that no critical material degradation occurs due to the potentially increased hydrogen uptake. For this reason the paper introduces the state of the art in pipeline hot tapping encompassing current research projects and their individual solution strategies for the problems that may arise for future hydrogen service. Methods of material testing their limitations and possible solutions will be presented and discussed.

The gas equation of state (EOS) serves as a critical tool for analyzing the thermal effects within the hydrogen storage tank during refueling processes. It quantifies the dynamic relationships among pressure temperature and volume playing a vital role in numerical simulations of hydrogen refueling the development of refueling protocols and ensuring refueling safety. This study first establishes a lumped-parameter thermodynamic model for the hydrogen refueling process which combines a zero-dimensional gas model with a one-dimensional tank wall model (0D1D). The model’s accuracy was validated against experimental data and will be used in combination with different EOSs to simulate hydrogen temperature and pressure. Subsequently parameter values are derived for the van der Waals EOS and its modified forms—Redlich–Kwong Soave and Peng–Robinson. The accuracy of the modified forms is evaluated using the Joule–Thomson inversion curve. A polynomial EOS is formulated and its parameters are numerically determined. Finally the hydrogen temperatures and pressures calculated using the van der Waals EOS Redlich– Kwong EOS polynomial EOS and the National Institute of Standards and Technology (NIST) database are compared. Within the initial and boundary conditions set in this study the results indicate that among the modified forms for van der Waals EOS the Redlich– Kwong EOS exhibits higher accuracy than the Soave and Peng–Robinson EOSs. Using the NIST-calculated hydrogen pressure as a benchmark the relative error is 0.30% for the polynomial EOS 1.83% for the Redlich–Kwong EOS and 17.90% for the van der Waals EOS. Thus the polynomial EOS exhibits higher accuracy followed by the Redlich–Kwong EOS while the van der Waals EOS demonstrates lower accuracy. This research provides a theoretical basis for selecting an appropriate EOS in numerical simulations of hydrogen refueling processes.

A numerical sensitivity analysis of a hydrogen pore storage system is carried out on a reservoir-scale geological model of the Ketzin site (Germany) to analyze the influence of uncertainty in geological parameters and fluid properties on storage performance. Therefore the following physical geological parameters and fluid properties were investigated: Porosity and permeability of the reservoir rock the brine salinity relative permeability and capillary pressure and mechanical dispersion. The range of the applied parameters is based on experimental and field data of the chosen location obtained during the former CO2 storage projects at the Ketzin site from 2008 to 2013. Using the open-source reservoir software MUFITS for the numerical simulations strong differences between the results can be observed. The results were evaluated based on measures to quantify performance such as the ratio of produced hydrogen mass to produced cushion gas (nitrogen) productivity index and sustainability index. The strongest impact on the performance parameters was observed with variations in the capillary pressure and the relative permeability curves followed by the absolute permeabilities while the least impact was seen with changes in the porosity and salinity of the brine. This work is not only crucial as a pre-feasibility study for the Ketzin storage site for hydrogen storage but also as a basis for decision-making for other potential storage sites in sedimentary basins.

As the transport of gaseous hydrogen and its use as a low carbon-footprint energy vector become increasingly likely scenarios both the scientific literature and technical standards addressing the compatibility of pipeline steels with high-pressure hydrogen environments are rapidly expanding. This work presents a detailed review of the most relevant hydrogen embrittlement testing methodologies proposed in standards and the academic literature. The focus is placed on testing approaches that support design-oriented assessments rather than simple alloy qualification for hydrogen service. Particular attention is given to tensile tests (conducted on smooth and notched specimens) as well as to J-integral and fatigue tests performed following the fracture mechanics’ approach. The influences of hydrogen partial pressure and deformation rate are critically examined as these parameters are essential for ensuring meaningful comparisons across different studies.

The resilience and sustainable development of modern power distribution systems faces escalating challenges due to increasing renewable integration and extreme events. Traditional single-system approaches often overlook the spatiotemporal coordination of cross-domain restoration resources. In this paper we propose a multi-stage resilience enhancement method that employs transportation and hydrogen energy systems. This approach coordinates the pre-event preventive allocation and multi-stage collaborative scheduling of diverse restoration resources including remote-controlled switches (RCSs) mobile hydrogen emergency resources (MHERs) and hydrogen production and refueling stations (HPRSs). The proposed framework supports cross-stage dynamic optimization scheduling enabling the development of adaptive resource dispatch strategies tailored to the characteristics of different stages including prevention fault isolation and service restoration. The model is applicable to complex scenarios involving dynamically changing network topologies and is formulated as a mixed-integer linear programming (MILP) problem. Case studies based on the IEEE 33-bus system show that the proposed method can restore a distribution system’s resilience to approximately 87% of its normal level following extreme events.