Institution of Gas Engineers & Managers

The use of hydrogen as an energy carrier within the scope of the decarbonisation of the world’s energy production and utilisation is seen by many as an integral part of this endeavour. However the discussion around hydrogen technologies often lacks some perspective on the currently available technologies their Technology Readiness Level (TRL) scope of application and important performance parameters such as energy density or conversion efficiency. This makes it difficult for the policy makers and investors to evaluate the technologies that are most promising. The present study aims to provide help in this respect by assessing the available technologies in which hydrogen is used as an energy carrier including its main challenges needs and opportunities in a scenario in which fossil fuels still dominate global energy sources but in which renewables are expected to assume a progressively vital role in the future. The production of green hydrogen using water electrolysis technologies is described in detail. Various methods of hydrogen storage are referred including underground storage physical storage and material-based storage. Hydrogen transportation technologies are examined taking into account different storage methods volume requirements and transportation distances. Lastly an assessment of well-known technologies for harnessing energy from hydrogen is undertaken including gas turbines reciprocating internal combustion engines and fuel cells. It seems that the many of the technologies assessed have already achieved a satisfactory degree of development such as several solutions for high-pressure hydrogen storage while others still require some maturation such as the still limited life and/or excessive cost of the various fuel cell technologies or the suitable operation of gas turbines and reciprocating internal combustion engines operating with hydrogen. Costs below 200 USD/kWproduced lives above 50 kh and conversion efficiencies approaching 80% are being aimed at green hydrogen production or electricity production from hydrogen fuel cells. Nonetheless notable advances have been achieved in these technologies in recent years. For instance electrolysis with solid oxide cells may now sometimes reach up to 85% efficiency although with a life still in the range of 20 kh. Conversely proton exchange membrane fuel cells (PEMFCs) working as electrolysers are able to sometimes achieve a life in the range of 80 kh with efficiencies up to 68%. Regarding electricity production from hydrogen the maximum efficiencies are slightly lower (72% and 55% respectively). The combination of the energy losses due to hydrogen production compression storage and electricity production yields overall efficiencies that could be as low as 25% although smart applications such as those that can use available process or waste heat could substantially improve the overall energy efficiency figures. Despite the challenges the foreseeable future seems to hold significant potential for hydrogen as a clean energy carrier as the demand for hydrogen continues to grow particularly in transportation building heating and power generation new business prospects emerge. However this should be done with careful regard to the fact that many of these technologies still need to increase their technological readiness level before they become viable options. For this an emphasis needs to be put on research innovation and collaboration among industry academia and policymakers to unlock the full potential of hydrogen as an energy vector in the sustainable economy.

This study identifies limitations and research and development (R&D) gaps at both the component and system levels for hydrogen energy systems (HESs) and specifies how these limitations impact HES adoption within the electric power system (EPS) decarbonization roadmap. To trace these limitations and potential solutions an analytical review is conducted in electrification and integration of HESs renewable energy sources (RESs) and multi-carrier energy systems (MCESs) in sequence. The study also innovatively categorizes HES integration challenges into component and system levels. At the component level technological aspects of hydrogen generation storage transportation and refueling are explored. At the system level HES coordination hydrogen market frameworks and adoption challenges are evaluated. Findings highlight R&D gaps including misalignment between HES operational targets and techno-economic development integration insufficiency model deficiencies and challenges in operational complexity. This study provides insights for sustainable energy integration by supporting the transition to a decarbonized energy system.

It is essential to use alternative fuels if we are to reach the emission reduction targets set by the IMO. Hydrogen carriers are classified as zero-emission while having a higher energy density (including packing factor) than pure hydrogen. They are often considered as safe alternative fuels. The exact definition of what safety entails is often lacking both for hydrogen carriers as well as for ship safety. The aim of this study is to review the safety of hydrogen carriers from two perspectives investigating potential connections between the chemical and maritime approaches to safety. This enables a reasoned consideration between safety aspects and other design drivers in ship design and operation. The hydrogen carriers AB NaBH4 KBH4 and two LOHCs (NEC and DBT) are taken into consideration together with a couple reference fuels (ammonia methanol and MDO). After the evaluation of chemical properties related to safety and the scope of the current IMO safety framework it can be concluded that safety remains a vague and non-explicit concept from both perspectives. Therefore further research is required to prove the safe application of hydrogen carriers onboard ships.

The pressure to move to sustainable energy sources is obvious in today's fast changing energy environment. In this context green hydrogen appears as a beacon of hope with the potential to reinvent the paradigms of energy consumption particularly in the transportation and aviation sectors. Hydrogen has long been intriguing owing to its unique characteristics. It is not only an energy transporter; it has the power to alter the game. Its growing significance is due to its capacity to decarbonize energy generation. Traditional hydrogen generation techniques have contributed considerably to world CO2 emissions accounting for over 2% of total emissions. This environmental problem is successfully addressed by the development of green hydrogen which is created from renewable energy sources. The International Energy Agency (IEA) predicts a 25 to 30 percent increase in global energy consumption by 2040 which is a very grim scenario. If continue to rely on coal and oil this growing demand will result in greater CO2 emissions exacerbating climate change's consequences. In this situation green hydrogen is not only an option but a need. Because green hydrogen has properties with conventional fuels it can be simply integrated into current infrastructure. This harmonic integration ensures that the shift to hydrogen-based solutions in these sectors would not demand a complete redesign of the present systems assuring cost-effectiveness and practicality. However like with any energy source green hydrogen has obstacles. Its combustibility and probable explosiveness have been cited as causes for concern. However developments in safety measures have successfully mitigated these dangers ensuring that hydrogen may be used safely and efficiently across various applications. A further difficulty is its energy density particularly in comparison to conventional fuels. While its energy-to-weight ratio may be good its bulk poses challenges particularly in the aviation industry where space is at a premium. Beyond its direct use as a fuel green hydrogen has potential in auxiliary capacities. It may be used as a dependable backup energy source during power outages as well as in a variety of different sectors and uses ranging from manufacturing to residential. Green hydrogen's adaptability demonstrates its potential to infiltrate all sectors of our economy. Storage is an important enabler for broad hydrogen use. Effective hydrogen storage technologies guarantee not only its availability but also its viability as a source of energy. Current research and advancements in this field are encouraging which strengthens the argument for green hydrogen. At conclusion green hydrogen is in the vanguard of sustainable energy solutions particularly for the transportation and aviation industries. In our collaborative quest of a sustainable future its unique features and environmental advantages make it a vital asset. As we explore further into the complexities of green hydrogen in this publication we want to shed light on its potential obstacles and future route.

This study uses a multi-method design to investigate the media’s role in shaping Germans’ attitudes toward green hydrogen. It combines an automatized content analysis of 7649 German newspaper articles published between July 2021 and June 2024 and a three-wave panel survey of the German population conducted between June 2023 and June 2024 with an initial sample of 2701 participants. The findings show that the intensity of media reporting on hydrogen was low compared to other energy-related topics. Nevertheless participants’ assessments of relative topic presence are rather accurate (rho: 0.50–0.80). A considerable number of participants were unable to position themselves toward the potential and challenges of hydrogen (23%–35%). Overall the results indicate that media and communication tend to stabilize or change existing attitudes rather than contribute to the formation or loss of attitudes leading to implications for the communication of relevant stakeholders.

Despite Iran’s considerable renewable energy (RE) potential and excellent wind capacity and high solar radiation levels these sources contribute only a small fraction of the country’s total energy production. This paper addresses the techno-economic viability of gray hydrogen production by these renewables with a particular focus on solar energy. Given the considerable potential of solar energy and the strategic location of Shahrekord it would be an optimal site for a hydrogen generation plant integrated with a solar field. HOMER Pro 3.18.3 software was utilized to model and optimize the levelized cost of hydrogen (LCOH) of steam reforming using different hydrocarbons in various scenarios. The results of this study indicate that natural gas (NG) reforming represents the most cost-effective method of gray hydrogen production in this city with an LCOH of −0.423 USD/kg. Other hydrocarbons such as diesel gasoline propane methanol and ethanol have a price per kilogram of produced hydrogen as follows: USD −0.4 USD −0.293 USD 1.17 USD 1.48 and USD 2.15. In addition integrating RE sources into hydrogen production was found to be viable. Moreover by implementing RE technologies CO2 emissions can be significantly reduced and energy security can be achieved.

Inspired by the announcement of the new Hydrogen Strategy for the UK in 2021 this study aimed to determine how the oil and gas industry responds and adapts to the changes. This paper analyses qualitative and quantitative data from the companies’ annual and energy reports. Four oil and gas companies involved in hydrogen projects in the UK were selected as case studies. The responses from the companies were collected using the content analysis research strategy in 2019–2021. A steady increase was observed based on the code frequency reflecting the increasing discussions and actions the companies took regarding this hydrogen pathway. Although only one company appears to be at the forefront of this transition progress with a score of almost 90% based on the strategy management analysis other companies continue to demonstrate their commitment to supporting the national target.

With the continuous development of hydrogen storage systems power-to-gas (P2G) and combined heat and power (CHP) the coupling between electricity–heat–hydrogen–gas has been promoted and energy conversion equipment has been transformed from an independent operation with low energy utilization efficiency to a joint operation with high efficiency. This study proposes a low-carbon optimization strategy for a multi-energy coupled IES containing hydrogen energy storage operating jointly with a two-stage P2G adjustable thermoelectric ratio CHP. Firstly the hydrogen energy storage system is analyzed to enhance the wind power consumption ability of the system by dynamically absorbing and releasing energy at the right time through electricity–hydrogen coupling. Then the two-stage P2G operation process is refined and combined with the CHP operation with an adjustable thermoelectric ratio to further improve the low-carbon and economic performance of the system. Finally multiple scenarios are set up and the comparative analysis shows that the addition of a hydrogen storage system can increase the wind power consumption capacity of the system by 4.6%; considering the adjustable thermoelectric ratio CHP and the twostage P2G the system emissions reduction can be 5.97% and 23.07% respectively and the total cost of operation can be reduced by 7.5% and 14.5% respectively.

For the safe and efficient utilization of hydrogen-enriched natural gas combustion in industrial gas-fired boilers the present study adopted a combination of numerical simulation and field tests to investigate its adaptability. Firstly the combustion characteristics of hydrogen-enriched natural gas with different hydrogen blending ratios and equivalence ratios were evaluated by using the Chemkin Pro platform. Secondly a field experimental study was carried out based on the WNS2- 1.25-Q gas-fired boiler to investigate the boiler’s thermal efficiency heat loss and pollutant emissions after hydrogen addition. The results show that at the same equivalence ratio with the hydrogen blending ratio increasing from 0% to 25% the laminar flame propagation speed of the fuel increases the extinction strain rate rises and the combustion limit expands. The laminar flame propagation speed of premixed methane/air gas reaches the maximum value when the equivalence ratio is 1.0 and the combustion intensity of the flame is the highest at this time. In the field tests as the hydrogen blending ratio increases from 0% to nearly 10% with the increasing excess air ratio the boiler’s thermal efficiency decreases as well as the NOx emission. This indicates that there exists a tradeoff between the boiler thermal efficiency and NOx emission in practice.

In this paper we aim to analyse the impact of hydrogen production decarbonisation and electrification scenarios on the infrastructure development generation mix CO2 emissions and system costs of the European power system considering the retrofit of the natural gas infrastructure. We define a reference scenario for the European power system in 2050 and use scenario variants to obtain additional insights by breaking down the effects of different assumptions. The scenarios were analysed using the European electricity market model COMPETES including a proposed formulation to consider retrofitting existing natural gas networks to transport hydrogen instead of methane. According to the results 60% of the EU’s hydrogen demand is electrified and approximately 30% of the total electricity demand will be to cover that hydrogen demand. The primary source of this electricity would be non-polluting technologies. Moreover hydrogen flexibility significantly increases variable renewable energy investment and production and reduces CO2 emissions. In contrast relying on only electricity transmission increases costs and CO2 emissions emphasising the importance of investing in an H2 network through retrofitting or new pipelines. In conclusion this paper shows that electrifying hydrogen is necessary and cost-effective to achieve the EU’s objective of reducing long-term emissions.