Publications

The energy transition is pushing towards a considerable diffusion of local energy communities based on renewable energy systems and coupled with energy storage systems or energy vectors to provide independence from fossil fuels and limit carbon emissions. Indeed the variable and intermittent nature of renewables make them inadequate to satisfy the end-users’ electricity demand throughout the whole day; thus the study of energy storage systems considering their seasonal storage behaviour (e.g. energy-power coupling selfdischarge loss and minimum state of charge) is fundamental to guarantee the proper energy coverage. This work aims at identifying the off-grid operation of a local energy community powered by a 220 kW small-scale hydropower plant in the center of Italy using either a battery energy storage system or a hydrogen one with the Calliope framework. Results show that whereas the hydrogen storage system is composed of a 137 kW electrolyser a 41 kW fuel cell and a storage of 5247 kgH2 a battery system storage system would have a capacity of 280 MWh. Even though the battery storage has a better round-trip efficiency its self-discharge loss and minimum state of charge limitation involve a discharging phase with a steeper slope thus requiring considerable economic investments because of the high energy-to-power ratio.

The demand for clean and sustainable energy solutions is escalating as the global population grows and economies develop. Fossil fuels which currently dominate the energy sector contribute to greenhouse gas emissions and environmental degradation. In response to these challenges hydrogen storage technologies have emerged as a promising avenue for achieving energy sustainability. This review provides an overview of recent advancements in hydrogen storage materials and technologies emphasizing the importance of efficient storage for maximizing hydrogen’s potential. The review highlights physical storage methods such as compressed hydrogen (reaching pressures of up to 70 MPa) and material-based approaches utilizing metal hydrides and carboncontaining substances. It also explores design considerations computational chemistry high-throughput screening and machine-learning techniques employed in developing efficient hydrogen storage materials. This comprehensive analysis showcases the potential of hydrogen storage in addressing energy demands reducing greenhouse gas emissions and driving clean energy innovation.

This work aims to investigate the time-resolved cost of electrolytic hydrogen in a future climate-neutral electricity system with high shares of variable renewable electricity generation in which hydrogen is used in the industry and transport sectors as well as for time-shifting electricity generation. The work applies a techno-economic optimization model which incorporates both exogenous (industry and transport) and endogenous (time-shifting of electricity generation) hydrogen demands to elucidate the parameters that affect the cost of hydrogen. The results highlight that several parameters influence the cost of hydrogen. The strongest influential parameter is the cost of electricity. Also important are cost-optimal dimensioning of the electrolyzer and hydrogen storage capacities as these capacities during certain periods limit hydrogen production thereby setting the marginal cost of hydrogen. Another decisive factor is the nature of the hydrogen demand whereby flexibility in the hydrogen demand can reduce the cost of supplying hydrogen given that the demand can be shifted in time. In addition the modeling shows that time-shifting electricity generation via hydrogen production with subsequent reconversion back to electricity plays an important in the climate-neutral electricity system investigated decreasing the average electricity cost by 2%–16%. Furthermore as expected the results show that the cost of hydrogen from an off-grid island-mode-operated industry is more expensive than the cost of hydrogen from all scenarios with a fully interconnected electricity system.

The Italian National Recovery and Resilience Plan (NRRP) includes among other measures investments in hydrogen vehicle refuelling stations intending to promote the use of fuel cell electric vehicles (FCEVs) for long-haul freight transport. This paper evaluates the impact that this action could have on CO2 emissions and fuel consumption focusing on a case study of the Campania region. The proposed approach which can also be transferred to other geographical contexts requires the implementation of a freight road transport simulation model; this model is based on the construction of a supply model the estimation of road freight demand and an assignment procedure for computing traffic flows. This study covers the period from 2025 to 2040 according to the forecasts of the NRRP and some assumptions on the action effects; moreover it is assumed that hydrogen is entirely produced from renewable sources (green hydrogen). The key findings from three different scenarios show that savings between 423832 and 778538 tonnes of CO2 and between 144 and 264 million litres of diesel could be obtained.

The existing combustion-centered energy mix in Malaysia has shown that replacing fossil fuels with zero-carbon alternative fuels could be a better approach to achieve the reduction of the carbon footprint of the power generation industry. In this study the potential of zero-carbon alternative fuels generated from renewable sources such as green hydrogen and green ammonia was addressed in terms of the production transport storage and utilization in Malaysia’s thermal power plants. The updated developments associated to green hydrogen and green ammonia across the globe have also been reviewed to support the existing potential in Malaysia. Though green hydrogen and green ammonia are hardly commercialized in Malaysia for the time being numerous potentialities have been identified in utilizing these fuels to achieve the zero-carbon power generation market in Malaysia. The vast and strategic location of natural gas network in Malaysia has the potential to deliver green hydrogen with minimal retrofitting required. Moreover there are active participation of Malaysia’s academic institutions in the development of water electrolysis that is the core process to convert the electricity from renewables plant into hydrogen. Malaysia also has the capacity to use its abundance of depleted gas reservoirs for the storage of green hydrogen. A large number of GT plants in Malaysia would definitely have the potential to utilize hydrogen co-firing with natural gas to minimize the amount of carbon dioxide (CO2) released. The significant number of ammonia production plants in Malaysia could provide a surplus of ammonia to be used as an alternative fuel for power plants. With regard to the energy policy in Malaysia positive acceptance of the implementation of renewable energy has been shown with the introduction of various energy policies aimed at promoting the incorporation of renewables into the energy mix. However there is still inadequate support for the implementation of alternative zero-carbon fuels in Malaysia.

Renewable and low carbon hydrogen is both an energy carrier able to produce other fuels and downstream products such as the e-fuels or e-ammonia and a decarbonised gas produced through renewable electricity. It has the potential to decarbonise hard to abate sectors which are difficult to directly electrify and play a crucial role in achieving net zero emissions target in 2050. The European Commission has recently outlined the policy context and necessary actions for the development and deployment of renewable and low carbon hydrogen within the 2030 time horizon with the Hydrogen Strategy for a Climate Neutral Europe Communication (the Hydrogen Strategy). The REPowerEU Communication4 has further addressed the joint EU and Member State actions needed in the context of the crisis triggered by the invasion of Ukraine in February 2022 and the necessity to phase out dependence on Russian supplies. The EC has strengthened the policy narrative around hydrogen and increased objectives for a pan European framework accelerating and upscaling the production of RES and low-carbon hydrogen. The main objectives and actions of the REPowerEU Plan which build on the Hydrogen Strategy are the deployment of several tens of GW of electrolyser capacity and the production and imports of 10 Mt and 10 Mt respectively of renewable hydrogen by 2030. Currently the most mature and promising green hydrogen production technology is water electrolysis. The main technologies5 considered in this report are: Alkaline electrolysis Polymer Exchange Membrane (PEM) electrolysis Solid Oxide electrolysis and Anion Exchange Membrane electrolysers (AEM).

Effective global decarbonization will require an array of solutions across a portfolio of low-carbon resources. One such solution is developing clean hydrogen. This unique fuel has the potential to minimize climate change impacts helping decarbonize hard-to-abate sectors such as heavy industry and global transport while also promoting energy security sustainable growth and job creation. The authors estimate suggest that hydrogen needs to grow seven-fold to support the global energy transition eventually accounting for ten percent of total energy consumption by 2050. A scaleup of this magnitude will increase demand for materials such as aluminum copper iridium nickel platinum vanadium and zinc to support hydrogen technologies - renewable electricity technologies and the electrolyzers for renewable hydrogen carbon storage for low-carbon hydrogen or fuel cells using hydrogen to power transport. This report a joint product of the World Bank and the Hydrogen Council examines these three critical areas. Using new data on the material intensities of key technologies the report estimates the amount of critical minerals needed to scale clean hydrogen. In addition it shows how incorporating sustainable practices and policies for mining and processing materials can help minimize environmental impacts. Key among these approaches is the use of recycled materials innovations in design in order to reduce material intensities and adoption of policies from the Climate Smart Mining (CSM) Framework to reduce impacts to greenhouse gas emissions and water footprint.

As a case study on sustainable energy use in educational institutions this study examines the design and integration of a solar–hydrogen storage system within the energy management framework of Kangwon National University’s Samcheok Campus. This paper provides an extensive analysis of the architecture and integrated design of such a system which is necessary given the increasing focus on renewable energy sources and the requirement for effective energy management. This study starts with a survey of the literature on hydrogen storage techniques solar energy storage technologies and current university energy management systems. In order to pinpoint areas in need of improvement and chances for progress it also looks at earlier research on solar–hydrogen storage systems. This study’s methodology describes the system architecture which includes fuel cell integration electrolysis for hydrogen production solar energy harvesting hydrogen storage and an energy management system customized for the needs of the university. This research explores the energy consumption characteristics of the Samcheok Campus of Kangwon National University and provides recommendations for the scalability and scale of the suggested system by designing three architecture systems of microgrids with EMS Optimization for solar–hydrogen hybrid solar–hydrogen and energy storage. To guarantee effective and safe functioning control strategies and safety considerations are also covered. Prototype creation testing and validation are all part of the implementation process which ends with a thorough case study of the solar–hydrogen storage system’s integration into the university’s energy grid. The effectiveness of the system its effect on campus energy consumption patterns its financial sustainability and comparisons with conventional energy management systems are all assessed in the findings and discussion section. Problems that arise during implementation are addressed along with suggested fixes and directions for further research—such as scalability issues and technology developments—are indicated. This study sheds important light on the viability and efficiency of solar–hydrogen storage systems in academic environments particularly with regard to accomplishing sustainable energy objectives.

Over the past few years the rapid growth of air traffic and the associated increase in emissions have created a need for sustainable aviation. Motivated by these challenges this paper explores how a 50-passenger regional aircraft can be hybridized to fly with the lowest possible emissions in 2040. In particular the use of liquid hydrogen in this aircraft is an innovative power source that promises to reduce CO2 and NOx emissions to zero. Combined with a fuel-cell system the energy obtained from the liquid hydrogen can be used efficiently. To realize a feasible concept in the near future considering the aspects of performance and security the system must be hybridized. In terms of maximized aircraft sustainability this paper analyses the flight phases and ground phases resulting in an aircraft design with a significant reduction in operating costs. Promising technologies such as a wingtip propeller and electric green taxiing are discussed in this paper and their potential impacts on the future of aviation are highlighted. In essence the hybridization of regional aircraft is promising and feasible by 2040; however more research is needed in the areas of fuel-cell technology thermal management and hydrogen production and storage.

We consider a profit-maximizing renewable energy producer operating in a rural area with limited electricity distribution capacity to the grid. While maximizing profits the energy producer is responsible for the electricity supply of a local community that aims to be self-sufficient. Energy storage is required to deal with the energy productions' uncertain and intermittent character. A promising new solution is to use strategic hydrogen reserves. This provides a long-term storage option to deal with seasonal mismatches in energy production and the local community's demand. Using a Markov decision process we provide a model that determines optimal daily decisions on how much energy to store as hydrogen and buy or sell from the power grid. We explicitly consider the seasonality and uncertainty of production demand and electricity prices. We show that ignoring seasonal demand and production patterns is suboptimal and that introducing hydrogen storage transforms loss-making operations into profitable ones. Extensive numerical experiments show that the distribution capacity should not be too small to prevent local grid congestion. A higher storage capacity increases the number of buying actions from the grid thereby causing more congestion which is problematic for the grid operator. We conclude that a profit-maximizing hydrogen storage operation alone is not an alternative to grid expansion to solve congestion which is essential knowledge for policy-makers and grid operators.

Green hydrogen will be an essential part of the future 100% sustainable energy and industry system. Up to one-third of the required solar and wind electricity would eventually be used for water electrolysis to produce hydrogen increasing the cumulative electrolyzer capacity to about 17 TWel by 2050. The key method applied in this research is a learning curve approach for the key technologies i.e. solar photovoltaics (PV) and water electrolyzers and levelized cost of hydrogen (LCOH). Sensitivities for the hydrogen demand and various input parameters are considered. Electrolyzer capital expenditure (CAPEX) for a large utility-scale system is expected to decrease from the current 400 €/kWel to 240 €/kWel by 2030 and to 80 €/kWel by 2050. With the continuing solar PV cost decrease this will lead to an LCOH decrease from the current 31–81 €/ MWhH2LHV (1.0–2.7 €/kgH2) to 20–54 €/MWhH2LHV (0.7–1.8 €/kgH2) by 2030 and 10–27 €/MWhH2LHV (0.3–0.9 €/kgH2) by 2050 depending on the location. The share of PV electricity cost in the LCOH will increase from the current 63% to 74% by 2050.

Many factors to be appropriately addressed in moving towards energy sustainability are examined. These include harnessing sustainable energy sources utilizing sustainable energy carriers increasing efficiency reducing environmental impact and improving socioeconomic acceptability. The latter factor includes community involvement and social acceptability economic affordability and equity lifestyles land use and aesthetics. Numerous illustrations demonstrate measures consistent with the approach put forward and options for energy sustainability and the broader objective of sustainability. Energy sustainability is of great importance to overall sustainability given the pervasiveness of energy use its importance in economic development and living standards and its impact on the environment.

The transition from fossil-based primary steel production to a low-emission alternative has gained increasing attention in recent years. Various schemes including Carbon Capture and Utilization (CCU) and Carbon Direct Avoidance (CDA) via hydrogen-based as well as electrochemical routes have been proposed. With multiple technical analyses being available and technical feasibility being proven by first pilot plants pathways towards commercial market entry are of increasing interest. While multiple publications on the economic feasibility of CCU are available data on CDA approaches is scarce. In this work an economic model for the quantification of production cost as well as CO2 emission mitigation cost is presented. The approach is characterized by a seamless integration with a flowsheet-based process model of a direct reduction-based crude steel production plant detailed in a previous work and allows for the investigation of multiple economic aspects. Firstly the gradual transition from the natural gas-based state-of-the-art direct reduction towards a fossil-free hydrogen-based reduction is analyzed. Furthermore a comparison between the more mature technology of low-temperature electrolysis and a potentially more efficient solid oxide electrolysis (SOEL) is given highlighting the potential of SOEL technology. The conducted forecast to 2050 shows that SOEL-based CDA offers lower production cost when technological maturity is reached. Based on the results of the economic assessment possible legislative support mechanisms are studied showing that legislative actions are necessary to allow for market entry as well as for sustainable and economically feasible operation of fossil-free direct reduction plants.

The development of innovative technologies based on employing green energy carriers such as hydrogen is becoming high in demand especially in the automotive sector as a result of the challenges associated with sustainable mobility. In the present review a detailed overview of the entire hydrogen supply chain is proposed spanning from its production to storage and final use in cars. Notably the main focus is on Polymer Electrolyte Membrane Fuel Cells (PEMFC) as the fuel-cell type most typically used in fuel cell electric vehicles. The analysis also includes a cost assessment of the various systems involved; specifically the materials commonly employed to manufacture fuel cells stacks and hydrogen storage systems are considered emphasizing the strengths and weaknesses of the selected strategies together with assessing the solutions to current problems. Moreover as a sought-after parallelism a comparison is also proposed and discussed between traditional diesel or gasoline cars battery-powered electric cars and fuel cell electric cars thus highlighting the advantages and main drawbacks of the propulsion systems currently available on the market.

Renewable hydrogen production has an important role in global decarbonization. However when coupled with intermittent and variable sources such as wind or PV electrolyzers are subjected to part-load and dynamic operation. This can lead to low utilization factors and faster degradation of the electrolyzers and affect the specific hydrogen cost. The design and sizing of such electrolysis systems are fundamental to minimize costs. In this study several configurations of an electrolysis system producing green hydrogen from a 39 MWwind farm are compared. The effects of both the size of the plant and the number of separated groups into which it is divided are investigated. Dividing the plant into two separated groups resulted to be enough to increase hydrogen production; a further increase in the number of groups didn't produce significant differences. The most profitable configurations resulted that with one or two groups depending on the hydrogen selling price.

Steam natural gas reforming is the preferred technique presently used to produce hydrogen. Proposed in 1932 the technique is very well established but still subjected to perfections. Herein first the improvements being sought in catalysts and processes are reviewed and then the advantage of replacing the energy supply from burning fuels with concentrated solar energy is discussed. It is especially this advance that may drastically reduce the economic and environmental cost of hydrogen production. Steam reforming can be easily integrated into concentrated solar with thermal storage for continuous hydrogen production.

In this episode of Hydrogen Europe's podcast "Hydrogen the first element" our CEO Jorgo Chatzimarkakis discusses with Wind Europe's CEO Giles Dickson. Starting off on how Giles joined Wind Europe the two CEOs discuss the responsibilities their industries have in the new energy strategy set in the REPowerEU as well as the fruitful synergies between hydrogen and wind.

Colombia a privileged country in terms of diversity availability of natural resources and geographical location has set a roadmap for hydrogen as part of the energy transition plan proposed in 2021. To reduce its emissions in the mid-term and foster its economy hydrogen production should be green and blue with specific targets set for 2030 for the hydrogen costs and produced quantities. This work compares the state-of-the-art production of blue and green hydrogen and how Colombia is doing in each pathway. A deeper analysis considers the advantages of Colombia’s natural resources the possible paths the government could follow and the feedstock’s geographical location for hydrogen production and transportation. Then one discusses what may be the next steps in terms of policies and developments to succeed in implementing the plan. Overall it is concluded that green hydrogen could be the faster more sustainable and more efficient method to implement in Colombia. However blue hydrogen could play an essential role if oil and gas companies assess the advantages of carbon dioxide utilization and promote its deployment.

In this paper we present the first systematic review of Power to X processes applied to the iron and steel industry. These processes convert renewable electricity into valuable chemicals through an electrolysis stage that produces the final product or a necessary intermediate. We have classified them in five categories (Power to Iron Power to Hydrogen Power to Syngas Power to Methane and Power to Methanol) to compare the results of the different studies published so far gathering specific energy consumption electrolysis power capacity CO2 emissions and technology readiness level. We also present for the first time novel concepts that integrate oxy-fuel ironmaking and Power to Gas. Lastly we round the review off with a summary of the most important research projects on the topic including relevant data on the largest pilot facilities (2–6 MW).

The hydrogen (H2) momentum affects the aviation sector. However a macroeconomic consideration is currently missing. To address this research gap the paper derives a methodology for evaluating macroeconomic effects of H2 in aviation and applies this approach to Germany. Three goals are addressed: (1) Construction of a German macroeconomic database. (2) Translation of H2 supply chains to the system of national accounts. (3) Implementation of H2-powered aviation into the macroeconomic data framework. The article presents an economy-wide database for analyzing H2-powered aviation. Subsequently the paper highlights three H2 supply pathways provides an exemplary techno-economic cost break-down for ten H2 components and translates them into the data framework. Eight relevant macroeconomic sectors for H2-powered aviation are identified and quantified. Overall the paper contributes on a suitable foundation to apply the macroeconomic dataset to and conduct macroeconomic analyses on H2-powered aviation. Finally the article highlights further research potential on job effects related to future H2 demand.

An unusual philosophical approach is proposed here to decarbonise larger civil aircraft that fly long ranges and consume a large fraction of civil aviation fuel. These inject an important amount of carbon emissions into the atmosphere and holistic decarbonising solutions must consider this sector. A philosophical–analytical investigation is reported here on the feasibility of an airliner family to fly over long ranges and assist in the elimination of carbon dioxide emissions from civil aviation. Backed by state-of-the-art correlations and engine performance integration analytical tools a family of large airliners is proposed based on the development and integration of the body of a very large two-deck four-engine airliner with the engines wings and flight control surfaces of a very long-range twin widebody jet. The proposal is for a derivative design and not a retrofit. This derivative design may enable a swifter entry to service. The main contribution of this study is a philosophical one: a carefully evaluated aircraft family that appears to have very good potential for first-generation hydrogen-fuelled airliners using gas turbine engines for propulsion. This family offers three variants: a 380-passenger aircraft with a range of 3300nm a 330-passenger aircraft with a range of 4800nm and a 230- passenger aircraft with a range of 5500nm. The latter range is crucially important because it permits travel from anywhere in the globe to anywhere else with only one stop. The jet engine of choice is a 450kN high-bypass turbofan.

Hydrogen is a key enabler of a sustainable society. Refurbishment of the existing natural gas infrastructure for up to 100% H2 is considered one of the most energy- and resource-efficient energy transportation methods. The question remains whether the transportation of 100% H2 with reasonable adaptions of the infrastructure and comparable energy amounts to natural gas is possible. The well-known critical components for refurbishment such as increased compressor power reduced linepack as well as pipeline transport efficiencies and their influencing factors were considered based on thermodynamic calculations with a step-by-step overview. A H2 content of 20–30% results in comparable operation parameters to pure natural gas. In addition to transport in pipelines decentralized H2 production will also play an important role in addressing future demands.

Solid oxide electrolysis cells (SOECs) have great application prospects because of their excellent performance but the long-term applications of the stacks are restricted by the structural degradation under the high-temperature conditions. Therefore an SOEC degradation model is developed and embedded in a process model of the high-temperature steam electrolysis (HTSE) system to investigate the influence of the stack degradation at the system level. The sensitivity analysis and optimization were carried out to study the influence factors of the stack degradation and system hydrogen production efficiency and search for the optimal operating conditions to improve the hydrogen production efficiency and mitigate the stack degradation. The analysis results show that the high temperature and large current density can accelerate the stack degradation but improve the hydrogen production efficiency while the high temperature gradually becomes unfavorable in the late stage. The low air-to-fuel feed ratio is beneficial to both the degradation rate and hydrogen production efficiency. The results show that the optimization method can improve the hydrogen production efficiency and inhibit the stack degradation effectively. Moreover part of the hydrogen production efficiency has to be sacrificed in order to obtain a lower stack degradation rate.

As a high-quality secondary energy hydrogen energy has great potential in energy storage and utilization. The development of power-to-hydrogen (P2H) technology has alleviated the problem of wind curtailment and improved the coupling between the power grid and the natural gas grid. Under the premise of ensuring safety using P2H technology to mix the produced hydrogen into the natural gas network for long-distance transmission and power generation can not only promote the development of hydrogen energy but also reduce carbon emissions. This paper presents a new model for incorporating hydrogen into natural gas pipelines. To minimize the sum of wind curtailment cost operation cost and carbon emission cost an electric–gas integrated energy system (EGIES) model of hydrogen-compressed natural gas (HCNG) containing P2H for power generation is constructed. Aiming at the problem of global warming caused by a lot of abandoned wind and carbon emissions the economy and environmental protection of the system model are analyzed. The results show that the model of EGIES considering HCNG can not only absorb excess wind power but also reduce carbon emission costs and system costs which can reduce the total cost of the environmental economic dispatch of the EGIES by about 34.1%. In the context of the EGIES the proposal of this model is of great significance to the economical and environmentally friendly operation of the system.

In this seventh episode Steffan Eldred Hydrogen Innovation Network Knowledge Transfer Manager and Jenni McDonnell MBE Heating and Cooling Knowledge Transfer Manager from Innovate UK KTN discuss why using hydrogen to generate heat is so important and explore the hydrogen economy opportunities and challenges within this sector alongside their special guest Jeff House Head of External Affairs Baxi Boilers.

The podcast can be found on their website.