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.

Hydrogen is a potential source of imminent clean energy in the future with its transportation playing a crucial role in allowing large-scale deployment. The challenge lies in selecting an effective sustainable and scalable transportation alternative. This study develops a multi-criteria decision-making (MCDM) framework based on the intuitionistic fuzzy analytic hierarchy process (IF-AHP) to evaluate land-based hydrogen transportation alternatives across Canada. The framework includes uncertainty and decision-maker hesitation through the application of triangular intuitionistic fuzzy numbers (TIFNs). Seven factors their subsequent thirty-three subfactors and three alternatives to hydrogen transportation were identified through a literature review. Pairwise comparison was aggregated among factors subfactors and alternatives from three decision makers using an intuitionistic fuzzy weighted average and priority weights were computed using entropy-based weight. The results show that safety and economic efficiency emerged as the most influential factors in the evaluation of hydrogen transportation alternatives followed by environmental impact security and social impact and public health in ascending order. Among the alternatives tube truck transport obtained the highest overall weight (0.3551) followed by pipelines (0.3272) and rail lines (0.3251). The findings suggest that the tube ruck is currently the most feasible transport option for land-based hydrogen distribution that aims to provide a transition of Canada’s energy mix.

Underground hydrogen storage (UHS) in depleted oil and gas fields is pivotal for balancing large-scale renewable-energy systems yet the wettability of reservoir rocks in contact with hydrogen after decades of Enhanced Oil Recovery (EOR) operations remains poorly quantified. This work experimentally investigates how two common EOR legacies cationic surfactant (city-trimethyl-ammonium bromide CTAB) and supercritical carbon dioxide (SC–CO2) flooding alter rock–water–Hydrogen (H2) wettability in carbonate formations. Contact angles were measured on dolomite and limestone rock slabs at 30–75 ◦C and 3.4–17.2 MPa using a high-pressure captive-bubble cell. Crude-oil aging shifted clean dolomite from strongly water-wet (θ ~ 28–29◦) to intermediate-wet (θ ≈ 84◦). Subsequent immersion in dilute CTAB solutions (0.5–2 wt %) fully reversed this effect restoring or surpassing the original water-wetness (θ ≈ 21–28◦). Limestone samples exposed to SC-CO2 at 60–80 ◦C became more hydrophilic (θ ≈ 18–30◦) relative to untreated controls; moderate carbonate dissolution (≤6 × 103 ppm Ca2+) produced the most significant improvement in water-wetness whereas severe dissolution yielded diminishing returns. These findings show that many mature reservoirs are already water-wet (post-CO2) or can be easily re-wetted (via residual CTAB). Across all scenarios sample wettability showed little sensitivity to pressure but higher temperature consistently promoted stronger water-wetness. Future work should include dynamic core-flooding experiments with realistic reservoir.

Hydrogen is considered a key alternative to fossil fuels in the broader context of ecological transition. Repurposing natural gas pipelines for hydrogen transport is one of the challenges of this approach. However hydrogen can diffuse into metallic lattices leading to hydrogen embrittlement (HE). For this reason typically ductile materials can experience unexpected brittle fractures and it is therefore necessary to assess the HE propensity of the current pipeline network to ensure its fitness for hydrogen transport. This study examines the relationship between the microstructure of the circumferential weld joint in X52 pipeline steel and hydrogen concentration introduced electrolytically. Base material heat affected zone and fused zone were subjected to 1800 3600 7200 and 14400 s of continuous charging with a current density J = − 10 mA/cm2 in an acid solution. Results showed that the fusion zone absorbed the most hydrogen across all charging times while the base material absorbed more hydrogen than the heat-affected zone due to the presence of non-metallic inclusions. Fracture toughness was assessed using single edge notch tension specimens (SENT) in air and electrolytic hydrogen. Results indicate that the base material is particularly vulnerable to hydrogen environments exhibiting the greatest reduction in toughness when exposed to hydrogen compared to air.

Green hydrogen is likely to play a major role in decarbonising the aviation industry. It is crucial to understand the effects of microstructure on hydrogen redistribution which may be implicated in the embrittlement of candidate fuel system metals. We have developed a multiscale finite element modelling framework that integrates micromechanical and hydrogen transport models such that the dominant microstructural effects can be efficiently accounted for at millimetre length scales. Our results show that microstructure has a significant effect on hydrogen localisation in elastically anisotropic materials which exhibit an interesting interplay between microstructure and millimetre-scale hydrogen redistribution at various loading rates. Considering 316L stainless steel and nickel a direct comparison of model predictions against experimental hydrogen embrittlement data reveals that the reported sensitivity to loading rate may be strongly linked with rate-dependent grain scale diffusion. These findings highlight the need to incorporate microstructural characteristics in hydrogen embrittlement models.

Underground Hydrogen Storage (UHS) offers a promising solution for large-scale energy storage yet suitable geological formations are often scarce. Unlined rock caverns (URCs) constructed in crystalline rocks like granite present a novel alternative particularly in regions where salt caverns or porous media are unsuitable. Despite their potential URCs remain largely unexplored for hydrogen storage. This study addresses this gap by providing one of the first comprehensive investigations into the geochemical interactions between hydrogen and granite host rock using a combined experimental and numerical approach. Granite powder samples were exposed to hydrogen and inert gas (N₂) in brine at room temperature and 5 MPa pressure for 14 weeks. Results showed minimal reactivity of silicate minerals with hydrogen indicated by negligible differences in elemental concentrations between H₂ and N₂ atmospheres. A validated geochemical model demonstrated that existing thermodynamic databases can accurately predict silicate‑hydrogen interactions. Additionally a kinetic batch model was developed to simulate long-term hydrogen storage under commercial URC conditions at Haje. The model predicts a modest 0.65 % increase in mineral volume over 100 years due to mineral precipitation which decreases net porosity and potentially enhances hydrogen containment by limiting leakage pathways. These findings support the feasibility of granite URCs for UHS providing a stable long-term storage option in regions lacking traditional geological formations. By filling a critical knowledge gap this study advances scalable hydrogen storage solutions contributing to the development of resilient renewable energy infrastructure.

The mismatch in renewable energy generation potential levelized cost and demand across different geographies highlight the potential of a future global green energy economy through the trade of green fuels. This potential and need call for modeling frameworks to make informed decisions on energy investments operations and regulations. In this work we present a multi-objective optimization framework for modeling and optimizing energy transmission strategies considering different generation locations transportation modes and often conflicting objectives of cost environmental impact and transportation risk. An illustrative case study on supplying renewable energy to Germany demonstrates the utility of the framework across diverse options and trade-offs. Sensitivity analysis reveals that the optimal energy carrier and transmission strategy depend on distance demand and existing infrastructure that can be re-purposed. The framework is adaptable across geographies and scales to offer actionable insights to guide investment operational and regulatory decisions in renewable energy and hydrogen supply chains.