Green hydrogen potentials from surplus hydro energy in Nepal

This paper studies the potentials of green hydrogen production from hydropower energy and its application in electricity regeneration and replacement of petroleum products from the transportation sector in Nepal. The potential surplus hydroelectric energy, and hydrogen production potential from the surplus energy considering different scenarios, is forecasted for the study period (2022–2030). The results showed that hydrogen production potential ranges from 63,072 tons to 3,153,360 tons with the utilization of surplus energy at 20% and 100% respectively, in 2030. The economic analysis of hydrogen from hydropower projects that electricity is valued based on per kg of hydrogen when the surplus electricity is provided at feasible lower price values compared to the US $1.17. This study concludes that hydrogen production from spilled hydro energy and its use in the transportation sector and independent electricity generation is a niche opportunity to lead the country towards sustainable energy solutions and an economy running on hydrogen.     

Hydrogen energy's key contributions to the sustainable energy mix of a low-carbon future in Nigeria

During the period between 2001 and 2007, oil prices increased from $20 to $140 per barrel, making oil prices higher than at any period in the twenty-first century. This was invariably good in gross domestic product terms for Nigeria which most regrettably, has continued to be a monoproduct oil economy since oil production started in the 1960s, with no value addition to the crude oil export. Indeed, the country still imports refined products to meet her domestic requirements, over 50 years after the first oil wells were drilled at Oloibiri in the Niger Delta region. Nigeria's proven oil reserves are reported as 36.2 billion barrels as at the end of 2010, with an R/P ratio of 42.4 and contributing 2.7% of world oil output (http://www.bp.com/assets/bp_internet/globalbp/globalbp_uk_english/reports_and_publications/statistical_energy_review_2011/STAGING/local_assets/pdf/statistical_review_of_world_energy_full_report_2011.pdf). While estimates indicate that the world has 43.44 years left of this non-renewable resource (http://www.bp.com/liveassets/bp_internet/globalbp/globalbp_uk_english/reports_and_publications/statistical_energy_review_2008/STAGING/local_assets/2010_downloads/statistical_review_of_world_energy_full_report_2010.pdf); with all assumptions associated with such estimates, upstream resource investment continues at the exploration end, and in Nigeria, new findings are frequently being announced which make the total resource estimate to be rather dynamic, as expected. An envisaged future built on hydrogen energy is known as the hydrogen economy since it has impacts on the economy, environment and society. Hydrogen can be produced from a variety of ‘raw materials’, some of which are abundantly available in Nigeria and they include natural gas, coal, biomass, agricultural and municipal wastes, and ocean water using energy from the sun and the wind. In light of the ongoing developments in the energy sector in Nigeria, the focus of this present review is to analyse the current energy situation with a view to estimating the potentials and implications of a hydrogen economy for Nigeria. Several issues and constraints are considered such as population growth, urbanisation, the transportation sector, production of hydrogen from fossil fuels as a short-term measure to developing a hydrogen infrastructure and ultimately clean production of hydrogen from renewable energy sources. This paper describes a future hydrogen economy from a climate change perspective that is based on production processes that have zero or near zero-carbon emissions to the environment. The economic impact aspects are, however, not addressed in this work. Nonetheless, the review provides a detailed and realistic assessment of the prospects of a hydrogen economy for a future low-carbon growth path for Nigeria.     

Hydrogen production from idle generation capacity of wind turbines

This paper is concerned with the hydrogen production from wind energy. It is motivated by the new regulations for wind farms that compel them to operate normally with idle generation capacity. The idea is to use the excess wind power to produce hydrogen. The operation of a proposed system configuration, which essentially consists in incorporating an electrolyzer between the electronic converters of a conventional wind turbine, is analyzed. In particular, the control requirements to simultaneously achieve the grid and electrolyzer specifications are investigated. In this context, a control strategy for the different operating modes of the system is developed.     

Hydrogen key technology to cover the energy storage needs of NEOM City

NEOM City is supposed to be a renewable-energy-only city in Saudi Arabia. The project has planned a huge capacity of non-dispatchable wind and solar photovoltaic but has not addressed yet the issue of a long time, large storage of energy. Battery energy storage is the only product off-the-shelf, and we know already only works for the storage of small amounts of energy over short time frames. The other solutions for energy storage are not off-the-shelf products, but in many cases, only nice ideas to be proven workable. The only other opportunity to make NEOM a truly renewable-energy-only City today is to use the extra wind and solar photovoltaic power to produce hydrogen through electrolyzers, and then partially use this hydrogen to produce the missing electricity to stabilize the grid, and export the excess hydrogen. Adopting extra wind and solar photovoltaic to make NEOM a hydrogen production hub in addition to a renewable-energy-only city is an even more attractive proposition. As NEOM has not fully acknowledged this issue, same as the scientific community, the most likely solution without an urgent debate within the scientific community will be to import electricity from the combustion of hydrocarbon fuels while paying carbon credits, with is inconsistent with the renewable-energy-only aspiration.     

Island wind-hydrogen energy: A significant potential US resource

Islands offer the advantages of notional deep ocean wind stations without the problems of mounting wind turbines in a hostile marine environment. In principle, island wind-power stations could take advantage of rich (up to Class 7) wind resources. Because connection to an electricity grid will be difficult for most island-based systems, electrical energy could be converted into hydrogen (by electrolyzing seawater) and stored for use on the island or shipped to the mainland. To attain the benefits of high-speed wind-turbine systems, several technical and policy issues, dealing with wind resources, specialized wind-turbine equipment, and the political and economic potential of island wind stations, need to be addressed. Until such multifaceted research can be completed, the technical potential for island-based wind turbines will remain just that—potential.     

Hydrogen in energy transition: A review

The energy transition is not something that awaits us in the next decade. On the contrary, it is a process in which we are already deeply enrolled. The main step towards the creation of a carbon-neutral society is the implementation of renewable energy sources (RES) as replacements for fossil fuels. Given the intermittency of RES, energy storage has an essential role to play in this transition. Hydrogen technology with its many advances was recognized to be the most promising choice. As multiple hydrogen applications were researched relatively recently, the current development of its technology is not yet on the large-scale implementation level. With the increasing number of studies and initiated projects, the utilization of hydrogen's immense ecological potential is to be expected in the next few decades. New innovative solutions of hydrogen technology that includes hydrogen production, storage, distribution, and usage, are permeating all industry sectors. In a rapidly changing world, technological advances bring forth public discussions, that are a deciding factor whether society will be able to adapt and accept those new contributions or reject them. Currently, hydrogen is the best associated with fuel cell electric vehicles which emit only water vapour and warm air, producing no harmful tailpipe emissions. As various scientists are stressing the gravity of climate change effects that are reaching the physical environment, ecosystems, and humanity in general, concern for the future is becoming the main global topic. Consequently, governments are implementing new sustainable policies that promote RES as a substitute for fossil fuels. Increasing progress in hydrogen technology instigated nations worldwide to incorporate hydrogen in their energy legislations and national development plans, which resulted in numerous national hydrogen strategies. This work shows the progress of hydrogen taking its place as a key factor of the future green energy society. It reviews recent developments of hydrogen technologies, their social, industrial, and environmental standing, as well as the stage of transitioning economies of both advanced and beginner countries. An example of the ongoing energy transition is Croatia, which is in the process of implementing a hydrogen strategy with the ambition to be able to one day equally participates in the rapidly emerging hydrogen market.     

A hydrogen economy and its impact on the world as we know it

An assortment of governmental, technological, environmental, and economic factors has combined to spur renewed interest in alternatives to petroleum, and especially in hydrogen. While there is no clear consensus on the viability of the technology, governments and corporations alike have vigorous hydrogen research programs. The result is that hydrogen may stand on the verge of becoming a true successor to oil. A transition from oil to hydrogen would alter familiar global economic and political structures in profound ways. The ramifications will influence developed and developing nations, oil importers, and exporters alike. New alliances among governments, corporations, and other groups may challenge existing notions of governance. Although a hydrogen-based economy may be decades away, the vision for it requires near- and mid-term thinking to manage the transition smoothly. Further, hydrogen is only a metaphor; any change from the current oil economy will entail dramatic changes to the global status quo that must be planned for now.     

Sustainable and energy efficient hydrogen production via glycerol reforming techniques: A review

Hydrogen-based energy solutions are among the alternative energy choices due to their clean emissions and high efficiency. H₂ is a highly convenient energy source, particularly if derived from sustainable feedstock. With the renewed emphasis on biodiesel production globally, large quantities of glycerol are expected to be produced as a major by-product. Reforming of this glycerol can provide a sustainable and H₂-rich feedstock. The study reveals that 7H₂ molecules were produced/molecule of glycerol in GSR, which is much higher than the commercially available SRM process. This also endorses the concept of circular economy and the 3Rs (Reuse, Reduce, and Recycle) by utilization of a by-product. This review highlights the recent advancements in different types of glycerol reforming technologies for H₂ production. The highly endothermic reaction and the coking of Ni-based catalysts are still the main limitations in its commercialization. It has been found that among different glycerol reforming techniques, the GSR is the finest with the least drawbacks. Hence, corresponding solutions to overcome these obstacles are deliberated.     

Techno-economic analysis for clean hydrogen production using solar energy under varied climate conditions

The paper discusses the feasibility of the use solar energy into hydrogen production using a photovoltaic energy system in the four main cities of Iraq. An off-grid photovoltaic system with a capacity of 22.0 kWp, an 8.0 kW alkaline electrolyser, a hydrogen compressor, and a hydrogen tank were simulated for one year in order to generate hydrogen. A mathematical model of the proposed system behavior is presented using MATLAB/Simulink, considering nine years from the 2021 to 2030 project span using hourly experimental weather data. The outcomes demonstrated that the annual hydrogen production ranged from 1713.92 kg up to 1891.12 kg, oxygen production ranged from 1199.74 to 1323.78 kg, and water consumption ranged from 7139.91 L to 7877.29 L. The hydrogen evaluated costs equal to $3.79/kg. The results show that the optimum site for solar hydrogen production systems can be established in the midwest of Iraq and in other cities with similar climates, especially those that get a lot of sunlight.     

Wind energy potential assessment for the Sultanate of Oman

Wind data analysis for the Sultanate of Oman is carried out in this study. The results are presented mainly in the form of contour maps, in addition to tabulated data and figures for average wind speed and direction as well as wind availability and power density spanning a period of ten years. The analysis covers diurnal, seasonal and height variations on wind parameters. The data used in the analysis were obtained from NASA Langley Research Center. This analysis provides a needed reference for the spatial distribution of wind characteristics for the whole of Oman from which possible locations for the deployment of wind-based energy conversion systems may be identified.     

Hydrogen electrical energy storage by high-temperature steam electrolysis for next-millennium energy security

It would be highly significant if energy, which is intimately related with the continued existence of human beings, were sustainable on the basis of the present resources for the next thousand years. The effectiveness of hydrogen for energy storage by high-temperature steam electrolysis is clarified by showing its features with reference to solar energy and nuclear energy for power storage as examples. It is also shown that use of hydrogen for energy storage would be effective for widespread utilization of current energy resources, such as renewables and nuclear energy, over the next millennium.     

Wave energy exploitation in the Ionian Sea Hellenic coasts: spatial planning of potential wave power stations

Wave energy represents the ‘new entry’ to Renewable Energy Sources discussion, in the context of clean and sustainable energy solutions in the electricity production sector. This research describes a geo-spatial Multiple-Criteria Decision Analysis, based on the Geographic Information Systems technology, for the identification of the best location to deploy a potential Wave Energy Farm in the Ionian Sea, an area offshore the Greek mainland West coast. For this purpose, several factors are taken into consideration; restrictions such as protected areas, military exercise areas etc. and weighted factors such as distance to power grid, wave height etc. The wave resource assessment is completed through real data measurements and numerical wave model approximations. The results pinpoint the most suitable areas for installing the proposed wave power plants, i.e. near the SW coast of Corfu, in the West side of the Straits between Kefallonia and Zakynthos and near the broader area of Pylos, in the SW coast of Peloponnesus. The suggested methodology can be equally applied in other spatial planning cases too, being considered as a checklist, addressed to policy-makers and private investors.     

生活中的潜在能源发掘与利用及可行性探讨

能源问题已经日益成为世界关注的焦点问题,能源利用与新能源开发也越来越多的引起各国的密切关注。在一次能源即将耗尽的今天,开发可再生、绿色环保、低投资高产出的新型能源必将成为世界热点话题。简略地分析了日常生活中能够利用的所谓潜在能源,列举了日常生活中振动发电,压力发电,温差发电,下水势能发电等具体的潜在能源方式。分别简略设计了各自的发电单元的基本原理和构成,并初步分析各中潜在能源利用的可行性。     

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.     

Modelling of energy systems with a high percentage of CHP and wind power

This paper presents the energy system analysis model EnergyPLAN, which has been used to analyse the integration of large scale wind power into the national Danish electricity system. The main purpose of the EnergyPLAN model is to design suitable national energy planning strategies by analysing the consequences of different national energy investments. The model emphasises the analysis of different regulation strategies and different market economic optimisation strategies.At present wind power supply 15% of the Danish electricity demand and ca 50% is produced in CHP (combined heat and power production). The model has been used in the work of an expert group conducted by the Danish Energy Agency for the Danish Parliament. Results are included in the paper in terms of strategies, in order to manage the integration of CHP and wind power in the future Danish energy supply in which more than 40% of the supply is expected to come from wind power.     

Regulatory frameworks for decentralised energy

This paper considers aspects of the current regulatory frameworks for markets and infrastructure which can inhibit the deployment of decentralised energy. The government has stated that decentralised energy can make a positive contribution to reducing the UK's carbon emissions, but recognises that at the moment the technologies face market and regulatory barriers. If it is to become a viable alternative to centralised generation, energy market design and the regulation of energy infrastructure will have to evolve to ensure that decentralised options are no longer locked out.     

Wind characteristics and wind energy potential in Morocco

The wind characteristics of 11 sites in the windy regions in Morocco have been analysed. The annual average wind speed for the considered sites ranged from 5 m/s to 10 m/s and the average power density from 100 W/m² to 1000 W/m², which might be suitable for electrical power production by installing wind farms. On an annual scale the observations of the distribution of hourly wind speed are better fitted by the Weibull hybrid distribution in contrast to the Weibull distribution.The wind power is estimated to be 1817 MW, that is to say, the exploitable wind energy is 15198 GWh, which represents theoretically 11% of the total consumed energy in Morocco in 1994.     

Hydrogen production by methanol aqueous electrolysis using photovoltaic energy: Algerian potential

Hydrogen is considered as the most promising energy carrier for providing a clean, reliable and sustainable energy system. It can be produced from a diverse array of potential feed stocks including water, fossil fuels and organic matter. Electrolysis is the best option for producing hydrogen very quickly and conveniently. Water electrolysis as a source of hydrogen production has recently gained much attention since it can produce high purity hydrogen and can be compatible with renewable energies. Besides the water electrolysis, aqueous methanol electrolysis has been reported in several studies. The aqueous methanol electrolysis proceeds at much lower voltage than that with the water electrolysis. As a result of the substantially lower operating voltage, the energy efficiency for methanol electrolysis can be higher than that for water electrolysis. In this paper, we are interesting to methanol electrolysis in order to produce hydrogen. The relation linking hydrogen production rate to the power needed to electrolyse a unit volume of aqueous methanol solution has been determined. Using this relation, the potential of hydrogen from aqueous methanol solution using a PV solar as the energy system has been evaluated for different locations in Algeria.     

Effect of compression ratio, equivalence ratio and engine speed on the performance and emission characteristics of a spark ignition engine using hydrogen as a fuel

The present energy situation has stimulated active research interest in non-petroleum and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. Researchers have found that hydrogen presents the best and an unprecedented solution to the energy crises and pollution problems, due to its superior combustion qualities and availability. This paper discusses analytically and provides data on the effect of compression ratio, equivalence ratio and engine speed on the engine performance, emissions and pre-ignition limits of a spark ignition engine operating on hydrogen fuel.These data are important in order to understand the interaction between engine performance and emission parameters, which will help engine designers when designing for hydrogen.     

Stable power supply of an independent power source for a remote island using a Hybrid Energy Storage System composed of electric and hydrogen energy storage systems

We propose a self-sustaining power supply system consisting of a “Hybrid Energy Storage System (HESS)” and renewable energy sources to ensure a stable supply of high-quality power in remote islands. The configuration of the self-sustaining power supply system that can utilize renewable energy sources effectively on remote islands where the installation area is limited is investigated. It is found that it is important to select renewable energy sources whose output power curve is close to the load curve to improve the efficiency of the system. The operation methods that can increase the cost-effectiveness of the self-sustaining power supply system are also investigated. It is clarified that it is important for increasing the cost effectiveness of the self-sustaining power supply system to operate the HESS with a smaller capacity of its components by setting upper limits on the output power of the renewable energy sources and cutting the infrequent generated power.