An economic survey of hydrogen production from conventional and alternative energy sources

A source of hydrogen is needed in the developing hydrogen economy, and many technologies are available for producing hydrogen from both conventional and alternative energy resources such as natural gas, coal, atoms, sunlight, wind, and biomass. The following paper summarizes the economics of producing hydrogen from each of these sources and gives an overview of the energy resource for each feedstock. The results of the analysis show that the most economical sources of hydrogen are coal and natural gas, with an estimated cost of 0.36–1.83 $/kg and 2.48–3.17 $/kg for each energy source, respectively. Alternative energy provides hydrogen at a higher cost; however, fossil fuel feedstock costs are increasing as technology enhancements are decreasing the cost of alternative energy sources, and therefore alternative energy sources may become more economical in the future.     

Measuring the relative efficiency of hydrogen energy technologies for implementing the hydrogen economy: An integrated fuzzy AHP/DEA approach

To provide and improve national energy security and low-carbon green energy economy, as a government-supported research institute related to developing new and renewable energy technologies, including energy efficiency, Korea Institute of Energy Research (KIER) needs to establish a long-term strategic energy technology roadmap (ETRM) in the hydrogen economy sector for sustainable economic development. In this paper, we establish a strategic ETRM for hydrogen energy technologies in the hydrogen economy considering five criteria: economic impact (EI), commercial potential (CP), inner capacity (IC), technical spin-off (TS), and development cost (DC). As an extended research, we apply the integrated two-stage multi-criteria decision-making approach, including the hybrid fuzzy analytic hierarchy process (AHP) and data envelopment analysis (DEA) model, to assess the relative efficiency of hydrogen energy technologies in order to scientifically implement the hydrogen economy. Fuzzy AHP reflects the vagueness of human thought with interval values, and allocates the relative importance and weights of four criteria: EI, CP, IC, and TS. The DEA approach measures the relative efficiency of hydrogen energy technologies for the hydrogen economy with a ratio of outputs over inputs.The result of measuring the relative efficiency of hydrogen energy technologies focuses on 4 hydrogen technologies out of 13 hydrogen energy technologies. KIER has to focus on developing 4 strategic hydrogen energy technologies from economic view point in the first phase with limited resources. In addition, if energy policy makers consider as some candidates for strategic hydrogen technologies of the other 9 hydrogen energy technology, the performance and productivity of 9 hydrogen energy technologies should be increased and the input values of them have to be decreased.With a scientific decision-making approach, we can assess the relative efficiency of hydrogen energy technologies efficiently and allocate limited research and development (R&D) resources effectively for well-focused R&D.     

Towards hydrogen economy in Lithuania

Hydrogen energy technologies can play a vital role in solving problems related to the energy sector. In order to create globally acceptable strategies in the development of hydrogen economy international groups have been created. In spite of multinational cooperation, national strategies on development of hydrogen energy technologies vary considerably from country to country due to different national constraints. Lithuania is also in the process of developing its national hydrogen energy strategy taking into account its national peculiarities. The first part of this article analyzes the strategy of hydrogen technology commercialization in the European Union and the second part analyzes the specific problems related to introduction of hydrogen energy technologies into the market in Lithuania.     

On the outlook for solar thermal hydrogen production in South Africa

Global warming and tightening environmental legislation is putting pressure on divesting from fossil fuel in the energy sector, with the transport sector likely to see the biggest changes. Current alternative energy sources are electric vehicles and hydrogen. Conventional hydrogen production technologies are fossil fuel based, emitting significant amounts of CO₂ into the atmosphere. This paper explores various ways to integrate solar thermal technologies into hydrogen production to generate carbon free hydrogen in South Africa. South Africa's abundant solar resource indicates that the country may become a significant player in the hydrogen market. However, the high capital cost associated with solar thermal energy put solar thermal hydrogen at a price disadvantage against conventional production technologies. Significant market penetration for solar thermal hydrogen is not expected within the next decade, but cost reduction due to improved manufacturing techniques and larger manufacturing volumes might close the gap in the long term.     

Potential of renewable hydrogen production for energy supply in Hong Kong

Hong Kong is highly vulnerable to energy and economic security due to the heavy dependence on imported fossil fuels. The combustion of fossil fuels also causes serious environmental pollution. Therefore, it is important to explore the opportunities for clean renewable energy for long-term energy supply. Hong Kong has the potential to develop clean renewable hydrogen energy to improve the environmental performance. This paper reviews the recent development of hydrogen production technologies, followed by an overview of the renewable energy sources and a discussion about potential applications for renewable hydrogen production in Hong Kong. The results show that although renewable energy resources cannot entirely satisfy the energy demand in Hong Kong, solar energy, wind power, and biomass are available renewable sources for significant hydrogen production. A system consisting of wind turbines and photovoltaic (PV) panels coupled with electrolyzers is a promising design to produce hydrogen. Biomass, especially organic waste, offers an economical, environmental-friendly way for renewable hydrogen production. The achievable hydrogen energy output would be as much as 40% of the total energy consumption in transportation.     

Large-vscale hydrogen production and storage technologies: Current status and future directions

Over the past years, hydrogen has been identified as the most promising carrier of clean energy. In a world that aims to replace fossil fuels to mitigate greenhouse emissions and address other environmental concerns, hydrogen generation technologies have become a main player in the energy mix. Since hydrogen is the main working medium in fuel cells and hydrogen-based energy storage systems, integrating these systems with other renewable energy systems is becoming very feasible. For example, the coupling of wind or solar systems hydrogen fuel cells as secondary energy sources is proven to enhance grid stability and secure the reliable energy supply for all times. The current demand for clean energy is unprecedented, and it seems that hydrogen can meet such demand only when produced and stored in large quantities. This paper presents an overview of the main hydrogen production and storage technologies, along with their challenges. They are presented to help identify technologies that have sufficient potential for large-scale energy applications that rely on hydrogen. Producing hydrogen from water and fossil fuels and storing it in underground formations are the best large-scale production and storage technologies. However, the local conditions of a specific region play a key role in determining the most suited production and storage methods, and there might be a need to combine multiple strategies together to allow a significant large-scale production and storage of hydrogen.     

Platform for promoting a hydrogen economy in Southwest Europe: The HYRREG project

The effective promotion of hydrogen technologies is best achieved when there is a strategy and a well defined and accepted plan for a hydrogen-based economy. The HYRREG project, funded by the Program of Cooperation of Southwest Europe (SUDOE), had as main objectives the development of a platform to generate hydrogen-related projects and a roadmap to enhance regional competitiveness and development of industry in this field in the SUDOE region which accounts for approximately 18% of the area and 12% of the population of the European Union. An analysis of the energy profiles in these regions reveals significant growth in capacity of renewable sources, principally from wind energy, yet the region has a high dependence on fossil fuels. The HYRREG consortium therefore believes that there is a good basis for supporting the development and introduction of hydrogen-based technologies in the region, especially with respect to the use of hydrogen for storage, to enhance security of supply and pave the way for a cleaner environment.     

Key strategies of hydrogen energy systems for sustainability

Here we conduct a parametric study to investigate the effects of hydrogen energy utilization on the global stability and sustainability. In this regard, in order to derive the hydrogen energy based sustainability ratio, the green energy based sustainability ratio, as developed earlier, is modified to come up with a new parameter, namely “hydrogen energy utilization ratio through non-fossil fuels”. We take actual historical data from key sources to determine the role of hydrogen energy for sustainability and make some future projections as the road map for hydrogen economy. In addition, an illustrative example on the hydrogen energy based sustainability ratio is presented by considering green energy sources such as solar, wind, hydro and nuclear to make hydrogen economy more environmentally benign and sustainable. It is found that hydrogen energy based global stability and sustainability ratios increase with the rise of hydrogen energy utilization ratio. The best results for hydrogen energy based sustainability ratio are obtained for the highest hydrogen energy impact ratios between 73.33% and 100%. In case of 10% of hydrogen energy utilization ratio, hydrogen based sustainability ratios for year 2010 are, respectively, determined to be 0.21%, 0.23%, 0.25%, 0.27% and 0.29% in 2.92% of hydrogen based global stability ratio by depending on the hydrogen energy impact ratios (=73.33%$=73.33\%$, 80%, 86.67%, 93.33% and 100%). In case of 20% of hydrogen energy utilization ratio, the hydrogen energy based sustainability ratios are found to be 1.09%, 1.19%, 1.28%, 1.38% and 1.48% in 7.41%, respectively. The results are really encouraging in a way that hydrogen economy appears to be one of the most significant players for better sustainability.     

Production of hydrogen for export from wind and solar energy,natural gas,and coal in Australia

Hydrogen production for export to Japan and Korea is increasingly popular in Australia. The theoretically possible paths include the use of the excess wind and solar energy supply to the grid to produce hydrogen from natural gas or coal. As a contribution to this debate, here I discuss the present contribution of wind and solar to the electricity grid, how this contribution might be expanded to make a grid wind and solar only, what is the energy storage needed to permit this supply, and what is the ratio of domestic total primary energy supply to electricity use. These factors are required to determine the likeliness of producing hydrogen for export. The wind and solar energy capacity, presently at 6.7 and 11.4 GW, have to increase almost 8 times up to values of 53 and 90 GW respectively to support a wind and solar energy only electricity grid for the southeast states only. Additionally, it is necessary to build-up energy storage of actual power >50 GW and stored energy >3000 GW h to stabilize the grid. If the other states and territories are considered, and also the total primary energy supply (TPES) rather than just electricity, the wind and solar capacity must be increased of a further 6–8 times. It is concluded that it is extremely unlikely that hydrogen for export could be produced from the splitting of the water molecule by using excess wind and solar energy, and it is very unlikely that wind and solar may fully cover the local TPES needs. The most likely scenario is production hydrogen via syngas from either natural gas or coal. Production from natural gas and coal needs further development of techniques, to include CO₂ capture, a way to reuse or store CO₂, and finally, the better energy efficiency of the conversion processes. There are several challenges for using natural gas or coal to produce hydrogen with near-zero greenhouse gas emissions. Carbon capture, utilization, and storage technologies that ensure no CO₂ is released in the production process, and new technologies to separate the oxygen from the air, and in case of natural gas, the water, and the CO₂ from the combustion products, are urgently needed to make sense of the fossil fuel hydrogen production. There is no benefit from producing hydrogen from fossil fuels without addressing the CO₂ issue, as well as the fuel energy penalty issue during conversion, that is simply translating in a net loss of fuel energy with the same CO₂ emission.     

Hydrogen fuel as an important element of the energy storage needs for future smart cities

A considerable amount of non-dispatchable photovoltaic and wind power have always been planned in smart cities, however, the problem of massive energy storage has not yet been solved which limits the use of green energy on larger scale. At present the only battery energy storage is available, and it is effective only for storing modest quantities of energy for short periods of time. The other storage technology options are not often commercially available items; rather, they are just good concepts that need to be tested for viability. Currently, the only alternative options for turning an urban development into one that exclusively uses green energy is to use that energy to generate hydrogen through electrolyzers, then use this fuel to generate the required electricity in order to stabilize the grid. Even more appealing is the idea of using wind and photovoltaic energy to transform smart communities into a centre for producing hydrogen in addition to a city that solely uses renewable energy. The most likely solution, absent an urgent debate inside the science establishment, will be to import electricity from the burning of hydrocarbons while continuing to pay carbon offsets, which is incompatible with the goal of using only renewables. The smart city has not officially accepted this issue, just like the science establishment.     

Development and assessment of a solar,wind and hydrogen hybrid trigeneration system

A solar-wind hybrid trigeneration system is proposed and analyzed thermodynamically through energy and exergy approaches in this paper. Hydrogen, electricity and heat are the useful products generated by the hybrid system. The system consists of a solar heliostat field, a wind turbine and a thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production linked with a hydrogen compression system. A solar heliostat field is employed as a source of thermal energy while the wind turbine is used to generate electricity. Electric power harvested by the wind turbine is supplied to the electrolyzer and compressors and provides an additional excess of electricity. Hydrogen produced by the thermochemical copper-chlorine (Cu-Cl) cycle is compressed in a hydrogen compression system for storage purposes. Both Aspen Plus 9.0 and EES are employed as software tools for the system modeling and simulation. The system is designed to achieve high hydrogen production rate of 455.1 kg/h. The overall energy and exergy efficiencies of the hybrid system are 49% and 48.2%, respectively. Some additional results about the system performance are obtained, presented and discussed in the paper.     

“Green” path from fossil-based to hydrogen economy: An overview of carbon-neutral technologies

While the dominant role of hydrogen in a sustainable energy future is widely accepted, the strategies for the transition from fossil-based to hydrogen economy are still actively debated. This paper emphasizes the role of carbon-neutral technologies and fuels during the transition period. To satisfy the world's growing appetite for energy and keep our planet healthy, at least 10 TW (or terawatt) of carbon-free power has to be produced by mid-century. Three prominent options discussed in the literature include: decarbonization of fossil energy, nuclear energy and renewable energy sources. These options are analyzed in this paper with a special emphasis on the role of hydrogen as a carbon-free energy carrier. In particular, the authors compare various fossil decarbonization strategies and evaluate the potential of nuclear and renewable energy resources to meet the 10 TW target. An overview of state-of-the-art technologies for production of carbon-free energy carriers and transportation fuels, and the assessment of their commercial potential is provided. It is shown that neither of these three options alone could provide 10 TW of carbon-neutral power without major changes in the existing infrastructure, and/or technological breakthroughs in many areas, and/or a considerable environmental risk. The authors propose a scenario for the transition from current fossil-based to hydrogen economy that includes two key elements: (i) changing the fossil decarbonization strategy from one based on CO₂ sequestration to one that involves sequestration and/or utilization of solid carbon, and (ii) producing carbon-neutral synthetic fuels from bio-carbon and hydrogen generated from water using carbon-free sources (nuclear, solar, wind, geothermal). This strategy would allow taking advantage of the existing fuel infrastructure without an adverse environmental impact, and it would secure a smooth carbon-neutral transition from fossil-based to future hydrogen economy.     

Evaluation of strategic directions for supply and demand of green hydrogen in South Korea

Currently, worldwide efforts are being made to replace fossil fuels with renewable energy to meet the goals of the Paris Agreement signed in 2015. Renewable energy, with solar and wind power as representative examples, focuses on hydrogen as a means of supplementing the intermittency in operation. Moreover, 17 advanced countries, including Australia and Europe, announced policies related to hydrogen, and Korea joined the ranks by announcing a roadmap to revitalize the hydrogen economy in 2019. As of 2020, the unit price of renewable energy in Korea is 0.1 $/kWh and 0.12 $/kWh for solar and wind power, respectively, which are more than five times higher than those of the world's best. The significant difference is due to the low utilization of power plants stemming from environmental factors. Consequently, securing the economic feasibility for the production of green hydrogen in Korea is difficult, and the evaluation of various policies is required to overcome these shortcomings. Currently, Korea's policy on renewable energy is focused on solar power, and despite the goal for a power generation of 57,483 GWh/year centered on offshore wind power by 2034, plans for utilization are lacking. By harnessing such energy, producing a percentage of the total green hydrogen required from the hydrogen economy roadmap can be realized, but securing economic feasibility may be difficult. Therefore, reinforcements in policies for the production of green hydrogen in Korea are required, and implementation of foreign policies for overseas cooperation in hydrogen production and import is necessary.     

The role of hydrogen in high wind energy penetration electricity systems: The Irish case

The deployment of wind energy is constrained by wind uncontrollability, which poses operational problems on the electricity supply system at high penetration levels, lessening the value of wind-generated electricity to a significant extent. This paper studies the viability of hydrogen production via electrolysis using wind power that cannot be easily accommodated on the system. The potential benefits of hydrogen and its role in enabling a large penetration of wind energy are assessed, within the context of the enormous wind energy resource in Ireland. The exploitation of this wind resource may in the future give rise to significant amounts of surplus wind electricity, which could be used to produce hydrogen, the zero-emissions fuel that many experts believe will eventually replace fossil fuels in the transport sector. In this paper the operation of a wind powered hydrogen production system is simulated and optimised. The results reveal that, even allowing for significant cost-reductions in electrolyser and associated balance-of-plant equipment, low average surplus wind electricity cost and a high hydrogen market price are also necessary to achieve the economic viability of the technology. These conditions would facilitate the installation of electrolysis units of sufficient capacity to allow an appreciable increase in installed wind power in Ireland. The simulation model was also used to determine the CO₂ abatement potential associated with the wind energy/hydrogen production.     

Optimizing hydrogen production capacity and day ahead market bidding for a wind farm in Texas

Producing green hydrogen from wind energy is one potential method to mitigate curtailment. This study develops a general approach to examine the economic benefit of adding hydrogen production capacity through water electrolysis along with the fuel cell and storage facilities in a wind farm in north Texas. The study also investigates different day ahead market bidding strategies in the existence of these technologies. The results show that adding hydrogen capacity to the wind farm is profitable when hydrogen price is greater than $3.58/kg, and that the optimal day ahead market bidding strategy changes as hydrogen price changes. The results also suggest that both the addition of a fuel cell to reconvert stored hydrogen to electricity and the addition of a battery to smooth the electricity input to the electrolyzer are suboptimal for the system in the case of this study. The profit of a particular bidding scenario is most sensitive to the selling price of hydrogen, and then the input parameters of the electrolyzer. This study also provides policy implications by investigating the impact of different policy schemes on the optimal hydrogen production level.     

Review on recent optimization strategies for hybrid renewable energy system with hydrogen technologies: State of the art,trends and future directions

The world is currently facing a power shortage due to the inadequacy of conventional energy sources and increased energy requirements in almost all sectors of human life. To mitigate this issue, the researchers have taken the considerable interest of researchers over the past decade in enhancing energy efficiency and viability. A hybrid renewable energy system (HRES) can efficiently produce clean energy to meet energy demand. Thus, it is extensively employed to improve power system quality, reliability, and economy, rather than solely relying on non-renewable energy sources. Nevertheless, RE sources' uncertain and intermittent nature, like wind speed and solar radiation, is associated with HRES. This problem can be solved with proper optimization by coupling HRES with energy conversion and storage devices, e.g., electrolyzer, fuel cell, and hydrogen tank, which can admirably balance power generation and energy demand. The literature is rich in employing optimization techniques on HRES with hydrogen technologies (HRES-H₂). However, a gap is found in the overall research progress of optimization approaches, considering HRES coupled with H₂ equipment. Therefore, the current study comprehensively reviews all the optimization approaches applied in this field worldwide. Further, a text mining-based software VOSviewer is used to investigate the scientific landscape of the literature body to figure out the current trends and future scope of HRES-H₂. It has been investigated that the researchers are focusing on: techno-economic optimization of HRES-H₂, developing sophisticated hydrogen infrastructure to reduce the overall cost of hydrogen fuel, introducing AI-based multi-objective optimization techniques to make the HRES-H₂ system more reliable and economically viable, and the impact of renewable and hydrogen technologies on the reduction of global warming. Lastly, an insightful of the current review highlighting the present shortcomings and opportunities of clean energy and hydrogen has been discussed, and suggestions are provided.     

Emerging technologies by hydrogen: A review

The majority of energy being used is obtained from fossil fuels, which are not renewable resources and require a longer time to recharge or return to its original capacity. Energy from fossil fuels is cheaper but it faces some challenges compared to renewable energy resources. Thus, one of the most potential candidates to fulfil the energy requirements are renewable resources and the most environmentally friendly fuel is Hydrogen. Hydrogen is a clean and efficient energy carrier and a hydrogen-based economy is now widely regarded as a potential solution for the future of energy security and sustainability. Hydrogen energy became the most significant energy as the current demand gradually starts to increase. It is an important key solution to tackle the global temperature rise. The key important factor of hydrogen production is the hydrogen economy. Hydrogen production technologies are commercially available, while some of these technologies are still under development. Therefore, the global interest in minimising the effects of greenhouse gases as well as other pollutant gases also increases. In order to investigate hydrogen implementation as a fuel or energy carrier, easily obtained broad-spectrum knowledge on a variety of processes is involved as well as their advantages, disadvantages, and potential adjustments in making a process that is fit for future development. Aside from directly using the hydrogen produced from these processes in fuel cells, streams rich with hydrogen can also be utilised in producing ethanol, methanol, gasoline as well as various chemicals of high value. This paper provided a brief summary on the current and developing technologies of hydrogen that are noteworthy.     

Integration of wind turbine with heliostat based CSP/CPVT system for hydrogen production and polygeneration: A thermodynamic comparison

In this study, two wind-solar-based polygeneration systems namely CES-1 and CES-2 are developed, modeled, and analyzed thermodynamically. CES-1 hybridizes a heliostat based CSP system with wind turbines while CES-2 integrates heliostat-based CPVT with wind turbines. This study aims to compare the production and thermodynamics performance of two heliostat based concentrated solar power technologies when hybridized with wind turbines. The systems have been modeled to produce, freshwater, hot water, electricity, hydrogen, and cooling with different cycles/subsystems. While the overall objective of the study is to model two polygeneration systems with improved energy and exergy performances, the performances of two solar technologies are compared. The wind turbine system integrated with the comprehensive energy systems will produce 1.14 MW of electricity and it has 72.2% energy and exergy efficiency. Also, based on the same solar energy input, the performance of the heliostat integrated CPVT system (CES-2) is found to be better than that of the CSP based system (CES-1). The polygeneration thermal and exergy efficiencies for the two systems respectively are 48.08% and 31.67% for CES-1; 59.7% and 43.91% for CES-2. Also, the electric power produced by CES-2 is 280 kW higher in comparison to CES-1.     

A regional decision support system for onsite renewable hydrogen production from solar and wind energy sources

Hydrogen technologies driven by renewable energy sources (RES) represent an attractive energy solution to ensure environmental sustainability. In this paper, a decision support system for the hydrogen exploitation is presented, focusing on some specific planning aspects. In particular, the planning aspects regard the selection of locations with high hydrogen production mainly based on the use of solar and wind energy sources. Four modules were considered namely, the evaluation of the wind and solar potentials, the analysis of the hydrogen potential, the development of a regional decision support module and a last module that regards the modelling of a hybrid onsite hydrogen production system. The overall approach was applied to a specific case study in Liguria region, in the north of Italy.     

Role of hydrogen in future North European power system in 2060

The Balmorel model has been used to calculate the economic optimal energy system configuration for the Scandinavian countries and Germany in 2060 assuming a nearly 100% coverage of the energy demands in the power, heat and transport sector with renewable energy sources. Different assumptions about the future success of fuel cell technologies have been investigated as well as different electricity and heat demand assumptions. The variability of wind power production was handled by varying the hydropower production and the production on CHP plants using biomass, by power transmission, by varying the heat production in heat pumps and electric heat boilers, and by varying the production of hydrogen in electrolysis plants in combination with hydrogen storage. Investment in hydrogen storage capacity corresponded to 1.2% of annual wind power production in the scenarios without a hydrogen demand from the transport sector, and approximately 4% in the scenarios with a hydrogen demand from the transport sector. Even the scenarios without a demand for hydrogen from the transport sector saw investments in hydrogen storage due to the need for flexibility provided by the ability to store hydrogen. The storage capacities of the electricity storages provided by plug-in hybrid electric vehicles were too small to make hydrogen storage superfluous.