Hydrogen-Based Energy Systems: Current Technology Development Status, Opportunities and Challenges

Abstract

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.

Comparative Technical and Economic Analyses of Hydrogen-Based Steel and Power Sectors

“…Due to limited data from the selected case study, additional technical specifications of DRI-EAF have been used for the current study [77]. Current available alkaline electrolyzer [63,64,78] with 2020 efficiency has a stack with a lifetime period of 60,000.00-80,000.00 h, and the electrolyzer units in the current study are operated during sunshine hours with an overall 51,100.00 h in the 20 years of HDRI-EAF's lifespan period. Operational expenditures on stack replacement for the electrolyzer were not included in the calculations of the LCOP.…”

Research on Hybrid Rectifier for High Power Electrolytic Hydrogen Production Based on Modular Multilevel Converter

“…Hydrogen holds great potential as a future energy source due to its cleanliness, high energy density, and efficient conversion. Electrolytic hydrogen production using renewable energy sources provides high purity and zero carbon emissions while effectively integrating fluctuating renewable energy and minimizing grid impact [1][2][3][4]. However, power consumption remains a significant consideration.…”

A Review of the Role of Hydrogen in the Heat Decarbonization of Future Energy Systems: Insights and Perspectives

“…Additionally, literature reviews on hydrogen energy systems provide insights into the challenges, prospects, and convergence with renewable energy sources (RESs), shedding light on the critical role of hydrogen in the transition to sustainable energy economies [8]. Different aspects of available technologies for utilizing hydrogen as an energy carrier in various countries such as the United Kingdom (UK), Germany, the United States, Norway, and Australia are demonstrated in [9]. Furthermore, the need for further research, innovation, and collaboration to maximize its potential in facilitating the decarbonization of global energy production and utilization is highlighted.…”