Challenges and Opportunities in Green Hydrogen Production

Green hydrogen, produced through environmentally friendly methods often involving renewable energy sources, holds the promise of transforming our energy landscape by offering a viable alternative to fossil fuels. This chapter serves as a gateway to understanding the multifaceted world of green hydrogen, a critical solution to our global energy challenges. It begins by introducing the fundamental concept of green hydrogen, emphasizing its significance as a clean, sustainable energy carrier. It explores how green hydrogen can contribute to sustainable development by reducing greenhouse gas emissions and enhancing energy efficiency. Furthermore, the chapter emphasizes the real-world applications of hydrogen across various sectors, including transportation, industry, and power generation. Within the context of green hydrogen production, the chapter delves into the challenges and opportunities of making hydrogen generation environmentally friendly. It introduces readers to various production methods and technologies that play a pivotal role in bridging the gap between our current energy systems and a greener future. Culminating with a glimpse into the cutting-edge innovations driving progress in green hydrogen production, this introductory chapter equips readers with the foundational knowledge and context required to navigate the challenges and seize the opportunities presented in subsequent sections. It invites readers to embark on a journey to uncover the intricacies of green hydrogen and its potential to revolutionize our energy paradigm.

In the present energy scenario with growing environmental and climate change concerns and increasing focus on energy security, global interest in low carbon hydrogen is increasing. In an energy system focussing on accelerated deployment of renewable energy systems, the role of hydrogen for balancing it is being increasingly recognised. Hydrogen for industrial use is traditionally produced from fossil fuels such as natural gas and coal, but cleaner hydrogen can be produced from renewable energy sources. Hydrogen is a colourless gas, but many colours have been associated with it depending on the energy sources used for its production and CO₂ emissions associated with it. The definition of green hydrogen is evolving, but hydrogen produced using renewable energy sources is generally considered as green. Presently, most of the hydrogen produced globally is grey as it is derived from fossil fuels without carbon capture. Hydrogen as a versatile energy vector finds several applications in industry, buildings, power, and transport sectors. Moreover, it can also be transformed into derivatives like ammonia, methanol etc. which are used as feedstocks for producing several industrial products and can also be used as green fuels, if produced from green hydrogen. Besides, substituting grey hydrogen used by the industry, green hydrogen can decarbonise many hard to abate industrial processes. However, there are several challenges associated with economically producing green hydrogen and its large-scale utilisation. This chapter discusses the above aspects of hydrogen energy in general and green hydrogen in particular in detail.

The advantages of hydrogen as a versatile and eco-friendly fuel are highlighted, along with its potential as a prospective energy resource for the future. The concept of a “hydrogen economy” is hinted at, wherein electricity and hydrogen work together as complementary energy sources. The text emphasizes the growing energy demand due to population growth and improved living standards. While fossil fuels currently dominate energy consumption, the focus is on sustainable alternatives like hydro, nuclear, solar, wind, geothermal, wave, and tidal energy. Hydrogen has a great potential for a future energy source. Only water vapor is released by hydrogen, which reduces air pollution and greenhouse gas emissions and highlights the flexible and environmentally friendly nature of hydrogen. It can be created using a range of resources, including renewable energy, which adds to its appeal. Nevertheless, it recognizes the existence of challenges and hurdles that must be addressed before hydrogen can be extensively adopted as a replacement for fossil fuels. There are several processes for creating hydrogen, including steam methane reforming, which recovers hydrogen from fossil fuels, and unconventional techniques including water electrolysis and thermochemical reactions. Hydrogen is a practical energy source in terms of environmental sustainability, energy effectiveness, and fuel variety.

As the global community grapples with the urgent need to combat climate change and transition toward a sustainable energy future, hydrogen has emerged as a promising solution. This paper presents a comprehensive exploration of hydrogen energy, its production, storage, and diverse applications, all of which are pivotal in advancing the goals of sustainable development. Hydrogen, when produced through green methods such as electrolysis powered by renewable energy, offers a clean and versatile energy carrier with the potential to decarbonize sectors traditionally reliant on fossil fuels. Furthermore, blue hydrogen, produced with carbon capture and storage, presents a transitional pathway toward reducing emissions while maintaining energy security. This chapter reviews the current state of hydrogen technology, examining key challenges such as production costs, infrastructure development, and energy storage. It highlights the role of hydrogen in transportation, industrial processes, and power generation, showcasing specific examples where hydrogen is reducing greenhouse gas emissions and improving air quality. The study also discusses ongoing research and development efforts aimed at enhancing the efficiency and affordability of hydrogen technologies. With nations worldwide committing to carbon neutrality, hydrogen energy represents a vital component of the sustainable energy landscape, fostering economic growth while mitigating the dire effects of climate change.

The production of green hydrogen has emerged as a promising solution to address global energy demands and environmental concerns. This chapter offers a comprehensive overview of sustainable pathways and technological advancements in green hydrogen production. Emphasizing its significance as a clean energy carrier, the chapter explores the utilization of renewable sources like solar, wind, and hydroelectric power for electrolysis processes. Various electrolysis methods, including alkaline, PEM, and SOEC, are discussed, highlighting their advantages, limitations, and commercial applications. Addressing challenges, the chapter emphasizes efficient energy storage and grid integration to balance intermittent power supply. Additionally, it explores green hydrogen’s integration with transportation, industry, and power generation for decarbonization goals. Recent technological advancements are examined, focusing on cutting-edge catalysts and materials to enhance electrolyzer performance and sustainability. Emerging technologies like photo-electrochemical and biological hydrogen production present novel alternatives to conventional electrolysis. Economic and policy aspects are explored, covering cost reduction strategies, research investments, and supportive policies. The importance of international collaboration for a sustainable energy transition is emphasized. Overall, this chapter serves as a valuable resource for researchers, policymakers, and industry professionals, offering insights into sustainable pathways, technological advancements, and the challenges and opportunities in green hydrogen production.

Hydrogen is being employed for more than only the typical industrial processes that involve creating ammonia, methanol, and refined petroleum. In recent years, there has been an increase in interest in the large-scale adoption of renewable energy-based power plants, as well as industrial and transportation uses, with a focus on manufacturing green hydrogen via the electrolysis process. Water electrolysis stands as a fundamental technique, involving the electrical decomposition of water into hydrogen and oxygen. Recent advances in alkaline water electrolysis have yielded impressive results, with energy efficiencies exceeding 70%. The photoelectrochemical water electrolysis, characterized by its proton-conductive membrane, demonstrates remarkable promise, boasting efficiency levels of up to 80%. Solid oxide cells represent a high-temperature option for hydrogen production, showcasing efficiencies above 70%. The burgeoning fields of photocatalytic and photoelectrochemical water splitting harness solar energy to drive the hydrogen evolution reaction. The results reveal that these technologies have achieved solar-to-hydrogen conversion efficiencies of up to 18%. These diverse approaches offer versatile solutions for green hydrogen production, vital for decarburization efforts. They address the need for sustainable, environmentally friendly, and secure energy sources, aligning with economic, environmental, and social considerations. As continue to advance these methodologies, hydrogen's role in our energy landscape grows, promising a cleaner and more sustainable future.

Hydrogen is the cleanest fuel among the existing with high calorific value ranging from 120 to 140 MJ/kg. It is being considered as ‘a fuel of the future’ from the global warming perspective due to very low or zero carbon emissions. Hydrogen energy is becoming a key component in bringing about the energy transition to ensure a sustainable future. Due to its very high potentials to capture the market in several fields, including automobiles, power generation, chemical, petrochemical and steel industries, and domestic uses, a lot of research has been going on and several innovations have been made in the technologies related to hydrogen production. It can be generated using fossil fuels as well as renewable sources which include natural gas, coal, nuclear, biomass, solar, wind, hydroelectric, and geothermal energy. This book chapter explores the potential of green hydrogen energy generation using renewable energy sources, including solar, wind, and hydroelectric power. It discusses the advantages of making use of renewable energy sources for green hydrogen generation, including the elimination of carbon emissions associated with traditional methods. This chapter also explores the challenges and opportunities associated with green hydrogen energy production with the help of renewable sources of energy, including the need for infrastructure development and investment in their research and development. Overall, this book chapter provides a comprehensive overview of the advantages of green hydrogen energy generation using renewable sources of energy and highlights its role in the gradual shift to a carbon–neutral economy along with future prospects.

Currently, significant efforts are being made to achieve near-zero greenhouse gas emissions. This transformation can be greatly facilitated by the development of new and improved procedures, with hydrogen being a promising source. Various methods, such as steam reforming, gasification of coal, and FT distillate process, are utilized to produce hydrogen. As a contemporary source, hydrogen can generate electrical power in a fuel cell, emitting only water vapor and warm air. The report acknowledges the benefits and usefulness of hydrogen in achieving a near-zero greenhouse effect. This project report delves into the production and application of hydrogen through electrochemical techniques. The main objective is to investigate different electrochemical methods for hydrogen production, including water electrolysis and photoelectrochemical cells. The report thoroughly examines the efficiency, cost-effectiveness, and scalability of these techniques. It starts with an overview of hydrogen, its production, and its significance in achieving sustainable energy goals. Subsequently, it explores various production methods, principles, and mechanisms of electrochemical processes for hydrogen generation while highlighting the advantages and limitations of each technique. Additionally, the report explores the storage and utilization of hydrogen for electricity generation and other applications while investigating potential challenges and opportunities associated with the real-world implementation of these technologies. Furthermore, it discusses the environmental benefits of hydrogen as a clean energy carrier and its potential to contribute to a sustainable and carbon–neutral future.

The only fuel, Green Hydrogen is recognized as a net zero carbon combustion product which favours environmental sustainability. It can be widely used to fulfil energy needs owing to its green impact on environment and many other advantages over the traditional fossil fuels. Green Hydrogen is becoming an inevitable alternate energy source replacing fossil fuels in industries, transportation, and also for decentralized power generation, aviation, and marine transport. Green Hydrogen is produced by an electrochemical process in which water molecules are dissociated with the help of electrolysis into hydrogen and oxygen. The potential technologies of producing Green Hydrogen are proton exchange membrane (PEM), alkaline cell, solid oxide electrolysis cells (SOEC), photo electrochemical (PEC) and solar-driven water splitting, biological and microbial electrolysis as well as hybrid technologies. These technologies have their own merits and demerits in production of Green Hydrogen in view of efficiency, cleanliness, production rate, initial cost, production cost, availability, and extent of sustainability. The present chapter provides the fundamental detailed description of these Green Hydrogen producing technologies along with their suitability and sustainability for the stated purpose. The durability of membrane, cost, and reliability are the main constraints limiting the usage of PEM for Green Hydrogen production in large scale. PEC is the potential green hydrogen producing technology and can be used to store abandoned solar energy in the form of Green Hydrogen. But the applicability of PEC is limited by its poor efficiency along with the sluggish reaction. Biological and microbial electrolysis can also be used as a suitable and sustainable Green Hydrogen producing technique as per its relevant zone of operation. The hybrid technologies are proposed by integrating multiple techniques with the objectives of enhancing Green Hydrogen production and reducing their adverse effects to enhance the sustainability of the aggregate process.

Hydrogen (H₂) production currently faces difficulties with regard to its feasibility in terms of cost competitiveness when compared to traditional fossil fuel-based H₂ production systems. In these conditions, producing green hydrogen (GH) using solar thermal systems (STS) is undoubtedly a viable and promising option. The present study examines recent developments in the application of various STSs for the production of GH with a focus on their actual analytical approach, application, scaling-up strategies, and economic viability, particularly in the context of tropical regions. GH offers an opportunity to decarbonize various critical sectors, such as transportation, industry, and power generation. It facilitates a smooth transition to a low-carbon economy and aids nations in achieving their climate goals. The chapter opens up with an emphasis on the value of renewable energy sources for the generation of power for any country in the introductory part. An overview of the various STSs used to produce H₂ is provided in the section that follows. The effectiveness and practicality of the new STSs used for GH generation are also critically assessed. This comprises life cycle evaluations, techno-economic analysis, and modeling and simulation approaches. Finally, the economics of GH production in developing nations using STSs is investigated. The critical observation and findings are intended to educate policymakers, researchers, and industry stakeholders on the potential of these technologies to promote sustainable development and energy transition in the targeted tropical regions.

The increasing human energy requirements necessitate the efficient utilization of renewable resources to ensure a sustainable power supply and mitigate the detrimental environmental impacts associated with fossil fuels. This need has motivated research towards water splitting as a way to generate hydrogen fuel since hydrogen is a prospective eco-friendly energy substitute for petroleum-based products. Photocatalytic water splitting with nanostructured metal oxides is one of the assuring means of large-scale, sustainable, and clean fuel production. This chapter focuses on H₂ production techniques with a specific and elaborative focus on photocatalytic H₂ production with UV and Visible light responsive photocatalysts. The UV light responsive metal oxides include TiO₂, Nb₂O₅, Ta₂O₅, and Ga₂O₃ and Visible light responsive metal oxides include WO₃, BiVO₄, Cu₂O, ZnO, etc. High stability, effective charge separation, and surface properties of photocatalysts discussed play a crucial role in photocatalysis. Different factors which influence the water splitting were also discussed in this book chapter. While significant steps have been taken in the advancement of alternative methods for generating hydrogen, further technical advancements and cost reductions are necessary to make them competitive with the prevailing large-scale reforming technology.

Water electrolysis or electrochemical water splitting is considered a promising technology for delivering a portable and sustainable energy source through hydrogen fuel. The crucial aspect for advancing toward industrial implementation rests in the utilization of cost-effective electrocatalysts with high efficiency. This book chapter provides a comprehensive overview of catalysts for electrochemical water splitting, emphasizing their importance, state-of-the-art advancements, challenges, and opportunities. Since catalysts play a critical role in facilitating efficient hydrogen production by improving reaction kinetics and selectivity, various catalyst types and their performance and stability evaluation are also explored. It highlights recent advancements in catalyst design, including nanostructuring and surface engineering. Challenges such as degradation, cost, and material availability are discussed, along with opportunities for innovation in earth-abundant catalysts and improved durability. This chapter aims to foster progress in catalyst design and development and inspire future research in electrolysis and electrochemical water splitting for sustainable hydrogen production.

Solar water splitting technology is a fast-rising approach and has offered a promise of producing renewable H₂ at a lower cost using non-toxic, inexpensive, and scalable materials for several years. Techno-economic analysis demonstrates that renewable H₂ production using direct solar water splitting can compete with photovoltaic (PV)-electrolyser technology if specific device stability and solar-to-hydrogen (STH) efficiency using scalable and earth-abundant semiconductor-based photoelectrodes are met. Various earth-abundant semiconductor materials as photoelectrodes have been designed and engineered to achieve enhanced water splitting performance. However, the poor STH efficiency and device stability of these earth-abundant photoelectrodes are the current challenges of solar water splitting technology to produce renewable H₂ at a large scale. The chapter explores solar-driven hydrogen production, focusing on efficient light absorption, charge separation, and catalytic processes. Key materials for semiconductor photocatalysts, photoelectrodes, and cocatalysts are discussed, highlighting their design principles and properties for solar energy conversion. Recent advancements, such as nanostructuring and surface modifications, are explored for improved light harvesting and catalytic activity. The chapter addresses challenges, including the poor STH efficiency and device stability, and presents an outlook on emerging materials and technologies like perovskite-based materials and earth-abundant catalysts. It concludes by emphasizing the importance of interdisciplinary collaborations and continued research efforts to accelerate the development and deployment of materials for solar-driven hydrogen production, contributing to renewable energy innovation.

Biohydrogen is regarded as an attractive renewable source of clean energy and an environmentally friendly alternative to conventional fossil fuels. BioH₂ can be produced via different biological pathways like direct and indirect biophotolysis, photo-fermentation, dark-fermentation, and bio-electrolysis using microbial electrolysis cells (MEC). The MEC is a bioelectrochemical approach that can be used to treat wastewater and produce biohydrogen, simultaneously. The MEC performance is highly affected by several factors such as microbial communities, cathode and anode catalysts’ activities, electrode materials and structures, current output, reactor design, associated anode and biocathode, catalysts, and substrate type, and concentration used. This chapter provides an overview of the recent developments in biological and non-biological materials involved in microbial electrolysis cells for biohydrogen production. The microbial species and enzymes, bio-inspired catalysts, advances in materials, and integration systems applied in these bioprocesses to improve catalytic performance, achieve lower configuration cost, and provide stable and efficient biohydrogen production are presented.

Hydrogen is considered as a promising source of renewable energy owing to its high energy content and minimal greenhouse gas emissions. The production of green-hydrogen from renewable sources such as water and biomass is increasingly gaining attention. This chapter provokes the urge to produce green-hydrogen (as the demand reaches 660 million metric tons annually by 2050) using carbon materials as an essential ingredient through various processes such as steam-reforming, water splitting, and photocatalysis. The main focus is to elaborate the recent development on carbon-based catalysts for these reactions, which are cost-effective, eco-friendly, easy to make and efficient. These materials are constituted with enormous features including high surface area, tuneable pore size, and unique electronic and chemical properties, which make them suitable for hydrogen production. This chapter also discusses the role of different types of carbon materials such as activated carbon (AC), carbon nanotubes (CNTs), carbon nanofibers (CNFs), 0D carbon quantum dots (CQDs), 2D/3D graphene, and carbide-derived carbon that can be used for green-hydrogen production. Additionally, the chapter highlights the factors that influence the performance of carbon-based catalysts, including morphology, structure, and surface chemistry. Overall, this special issue will contribute an outlook on the future of carbon-based materials towards the overall hydrogen economy and potential for industrial applications.

Using green hydrogen as a clean energy carrier has gained unprecedented attention in the global pursuit of sustainable energy solutions. This chapter delves into the pivotal role that two-dimensional (2D) materials play in advancing the field of green hydrogen production. With a focus on electrocatalytic and photoelectrochemical processes, this chapter explores how 2D materials possess unique properties that enable efficient hydrogen evolution and oxygen evolution reactions, crucial steps in water splitting. The application landscape of 2D materials in green hydrogen production is then unveiled, covering their roles in electrocatalytic hydrogen and oxygen evolution, as well as photoelectrochemical water splitting. The integration of 2D materials with renewable energy sources is explored, along with the technological challenges that must be overcome for successful implementation. The chapter culminates in a forward-looking analysis, outlining the emerging trends in 2D material research, computational modeling, stability enhancement, and economic feasibility. Through a blend of experimental insights and theoretical understanding, this chapter underscores the vital contribution of 2D materials to unlocking the potential of green hydrogen production. By shedding light on their remarkable catalytic properties and unveiling strategies for addressing challenges, this chapter serves as a springboard for researchers, policymakers, and industries invested in shaping a sustainable energy future.

Two-dimensional transition metal carbides and nitrides known as MXenes, having general formula of M_n+1X_n (where n = 1 to 3), tender the advantages of metallic conductive transition metals with large groups of carbides, nitrides, or carbonitrides moieties. Two-dimensional nanomaterials with intriguing applications in the electro- and photocatalytic water splitting are being developed by MXenes with distinctive properties. Due to their unique interface characteristics, MXene and semiconductor hybrids are regarded as effective photocatalysts and photoelectrodes. MXene has many uses for producing hydrogen through solar-powered water splitting. This chapter discusses in depth various MXene-based catalyst/electrode systems for splitting water.

Since centuries, human development in industry has been regularly correlated with fossil fuel combustion and the release of greenhouse gases. As the overall demand for energy has risen drastically in the modern era, the problems related to the reduction of energy resources and increased environmental pollution cannot be ignored. It is required to seek novel energy sources to avoid the risks associated with the reduction of non-renewable energy resources and health issues due to the emission of dangerous gases. Among all the alternative resources for the demand of energy for various applications, hydrogen energy has been recognized as a superlative candidate for water electrolysis to produce cost-effective clean energy. This is called a sustainable strategy due to the immense abundance of resources (i.e., water), the only production of water, superior energy density, and net-zero carbon emissions (negligible air pollution). For electrocatalytic hydrogen evolution reactions (HER), the basic requirement is the choice of better electrocatalysts. Various electrocatalysts such as precious (e.g., Pt, Pd, Ir, and Ru etc.), earth-abundant metal (e.g., Fe, Co, Ni, and Cu etc.), and metal-free electrocatalysts are established for a practical HER progression. With them, ruthenium (Ru)-derived electrocatalysts hold opposite hydrogen bonding energy, have a rational price, and behave as an excellent alternative to platinum (Pt) for HER activity. Thus, this chapter delivers a perception of the current breakthroughs in the field of Ru-electrocatalysts, their synthesis strategies, and progress towards their utilization in green hydrogen production. With this, it also addresses the prospects of Ru-electrocatalysts towards their implementation in large-scale green hydrogen production.

In recent years, green hydrogen has emerged as the prime solution for meeting the challenges of the energy crisis and climate change posed by the overuse of fossil fuels. Green hydrogen is the hydrogen produced from water-splitting reactions driven by renewable and sustainable energy resources such as solar, geothermal, hydro, wind, and biomass resources that do not emit greenhouse gases, such as carbon dioxide and others. There are other different mechanisms and conversion routes for producing green hydrogen. Due to the increasing demand for hydrogen for various applications such as steel, off-grid electricity, ammonia, agriculture, and automobiles, there is a need for large-scale green hydrogen production. This technology enhancement is required to meet the coveted target of USD 1 per kg, \(\textrm{H}_2\). There are some established technologies such as alkaline, polymer electrolyte membranes, and solid-oxide electrolyzers for hydrogen production. However, several challenges in their efficient utilization are being addressed through the use of suitable materials and design modifications at the appropriate scale of production. Therefore, there is a requirement for a multiscale modeling framework for the selection of compatible and efficient material, and optimum design parameters keeping in mind the safety aspects and the economic viability of scaling criteria. Modeling and digital-twin development are high-performance tools that enhance and utilize the capability of electrolyzers and the associated balance of plants to develop efficient coupling with renewable resources for more efficient hydrogen production. This chapter focuses on the modeling tools and techniques that have been employed to develop reliable models and digital twins of electrolyzers for understanding optimum operating conditions to produce cost-effective hydrogen with high efficiency of conversion in the optimum pressure range. In addition to this, challenges with materials and design aspects have been discussed with a focus on the development of efficient, low-cost electrocatalysts for anode and cathode, porous transport layers, gas diffusion layers, separators, and electrolyte membranes to achieve high conversion efficiency, low gas crossover, and others. In addition, in this chapter, a discussion of the different cell architectures and modular designs of membrane electrolyzers is presented to achieve better conversion efficiency, low gas dissolution, and higher flow rate of the produced hydrogen with minimum components. Moreover, scaling or sizing of the green hydrogen production systems from cells and stacks up to plants (10 MW to 1 GW) requires thorough techno-economic analysis taking into account the renewable energy capacity of the region and the costs of the equipment. Thus, discussions on the techno-economic analyses and case studies of such region-based and renewable energy resource-specific hydrogen production have been presented.

Energy is the very basic requirement for the sustainability of the human race and its development. Immediate action is needed to accelerate the development of technology that uses renewable energy sources such as sunlight, wind, tides, hydrogen, and waste heat management. Hydrogen is used to generate electricity in fuel cells, it has the potential to solve two major issues: the need for clean energy and global warming. Hydrogen is abundant and efficient source of clean energy as earth has a lot of hydrogen in the form of water and hydrocarbons and it exhibits complete combustion yielding only water. But a high risk is involved in hydrogen-based technology due to the lightest known element and highly inflammable nature of hydrogen. Materials need to be developed for appropriate hydrogen production, storage and detection to make economic, efficient and safe hydrogen technologies in order to compete with fossil fuels and for introducing a hydrogen-based economy. Several methods of compressed storage, hydrogen liquefaction, chemical absorption, and physical adsorption have been proposed so far for storing hydrogen. The broad use of hydrogen energy is hampered by concerns about compressed and liquified hydrogen’s safety, cost, and transportation. Due to its superior transit and storage capabilities, solid hydrogen storage materials are viable hydrogen storage technique. There are numerous physical and chemical ways to store hydrogen. Each storage method has benefits and drawbacks of its own. The key difficulties for hydrogen storage materials are hydrogen storage density, dehydrogenation temperature, and dehydrogenation kinetics. In this chapter, we have discussed various methods of the hydrogen storage and current developments in hydrogen storage materials as well. Merits and demerits of different materials and potential solutions given in literature for various challenges in these technologies have been discussed.

The transition towards a sustainable energy future has increased interest in green hydrogen production and fuel cell technology as viable solutions for decarbonizing the power sector. However, successfully integrating these technologies into the existing power grid presents opportunities and challenges that must be addressed to achieve a reliable and resilient energy system. This book chapter overviews the opportunities and challenges of integrating green hydrogen production and fuel cell technology with the power grid. It explores the potential benefits of coupling these technologies with the power grid, including energy storage, grid balancing, and sector coupling, enabling the utilization of renewable energy on a larger scale. The opportunities arising from the power grid integration of green hydrogen production include providing grid services through hydrogen storage and dispatchable power generation from fuel cells. The flexible operation of electrolyzers and fuel cells can help balance fluctuations in renewable energy supply and demand, supporting grid stability and enhancing the integration of intermittent renewable energy sources. However, several challenges need to be addressed for successful power grid integration. Additionally, establishing hydrogen infrastructure, including storage, transportation, and distribution systems, is crucial for enabling the widespread deployment of green hydrogen in various sectors. Furthermore, integrating fuel cells into the power grid requires addressing technical and economic barriers, such as optimizing fuel cell efficiency, and durability, and reducing manufacturing costs. This chapter emphasizes the need for collaborative efforts between policymakers, researchers, industry stakeholders, and grid operators to overcome the challenges and unlock the full potential of green hydrogen production and fuel cell technology in the power sector. It discusses the importance of demonstration projects, pilot studies, and real-world deployment to validate the technical, economic, and environmental feasibility of integrating these technologies into the power grid.

The production stage of green hydrogen, particularly through electrolysis, is confronted with numerous challenges. These include energy inefficiencies during the process, a lack of recognition of the inherent value of green hydrogen, complexities in maintaining sustainability, and elevated production costs. This chapter presents a detailed techno-economic examination of green hydrogen production, focusing on the balance between efficiency and sustainability. It commences by establishing the fundamental role of green hydrogen in a sustainable energy future, setting the stage for the assessment of various production techniques. Through this, we scrutinise the prevailing electrolysis methods, including alkaline, proton exchange membrane (PEM), solid oxide electrolysis, and anion exchange membrane (AEM) as well as emerging novel technologies. Each technique’s environmental footprint, energy efficiency, scalability, and cost factors are critically evaluated, drawing upon the latest research and advancements. Furthermore, we explore the influence of renewable energy integration on the economics and carbon emissions of green hydrogen production. This evaluation considers the variable nature of renewable energy sources and the potential of energy storage systems to manage this challenge. The chapter also delves into the policy frameworks shaping the green hydrogen sector, exploring how they could be leveraged to foster technological innovation and improve economic viability. Through this comprehensive analysis, we seek to provide insights into the optimisation of green hydrogen production processes and contribute to achieving a truly sustainable energy system.

Techno-economic aspects of green hydrogen production play a significant role in shaping the development and deployment of new hydrogen facilities. Comprehensive analyses of cost components that impact the levelized cost of green hydrogen have become increasingly important for supporting investment strategies and production planning processes. Furthermore, these analyses have proven valuable in decision-making processes related to the establishment of support mechanisms that ensure the sustainable energy transition of national and local power, heating, and transport sectors. This chapter identifies and discusses various metrics and factors affecting the nascent green hydrogen market. Additionally, this chapter is devoted to identifying the current economic trends and future prospects of green hydrogen production technologies, specifically alkaline, proton exchange membranes, and solid oxide water electrolysis powered by renewable energy sources. Finally, the chapter analyzes existing policy efforts and various policy instruments to promote green hydrogen as a critical element in the decarbonization of global economies.