Prospects for the production of green hydrogen: Review of countries with high potential

The article provides a review of the current hydrogen production and the prospects for the development of the production of “green” hydrogen using renewable energy sources in various countries of the world that are leaders in this field. The potential of hydrogen energy in such countries and regions as Australia, the European Union, India, Canada, China, the Russian Federation, United States of America, South Korea, the Republic of South Africa, Japan and the northern countries of Africa is considered. These countries have significant potential for the production of hydrogen and “green” hydrogen, in particular through mining of fossil fuels and the use of renewable energy sources. The quantitative indicators of the production of “green” hydrogen in the future and the direction of its export are considered; the most developed hydrogen technologies in these countries are presented. The production of “green” hydrogen in most countries is the way to transition from the consumption of fossil fuels to the clean energy of the future, which will significantly improve the environmental situation, reduce greenhouse gas emissions and improve the energy independence of the regions.     

Techno-economic analysis of adiabatic four-stage CO2 methanation process for optimization and evaluation of power-to-gas technology

Owing to increasing demands for clean energy, caused by global warming, renewable energy sources have attracted significant attention. However, these sources can affect the reliability of electrical grids owing to their intermittency. Power-to-gas technology is expected to help address this issue. In this study, the CO₂ methanation process, which yields synthetic natural gas (SNG) via the synthesis of CO₂ and H₂ through proton exchange membrane (PEM) water electrolysis using surplus electricity generated from renewable energy, was evaluated and optimized based on techno-economic analyses. Requirements for the introduction of SNG produced through CO₂ methanation in domestic natural gas markets are presented by considering various scenarios. Results indicate that, even if the electricity costs, including system marginal price and renewable energy costs, are minimal, the costs for PEM water electrolysis and CO₂ methanation must be reduced by ~$550/kW and 25%, respectively, relative to current levels for the viable introduction of SNG in domestic markets.     

Multi-objective assessment of rural electrification in remote areas with poverty considerations

Rural electrification with renewable energy technologies (RETs) offers several benefits to remote areas where diesel generation is unsuitable due to fuel supply constraints. Such benefits include environmental and social aspects, which are linked to energy access and poverty reduction in less-favored areas of developing countries. In this case, multi-objective methods are suitable tools for planning in rural areas. In this study, assessment of rural electrification with renewable energy systems is conducted by means of goal programming towards fuel substitution. The approach showed that, in the Non-Interconnected Zones of Colombia, substitution of traditional biomass with an electrification scheme using renewable energy sources provides significant environmental benefits, measured as land use and avoided emissions, as well as higher employment generation rates than diesel generation schemes. Nevertheless, fuel substitution is constrained by the elevated cost of electricity compared to traditional biomass, which raises households’ energy expenditures between twofold to five times higher values. The present approach, yet wide in scope, is still limited for quantifying the impact of energy access improvements on poverty reduction, as well as for the assessment of energy system's technical feasibility.     

Modelling and control of hydrogen and energy flows in a network of green hydrogen refuelling stations powered by mixed renewable energy systems

The planning of a hydrogen infrastructure with production facilities, distribution chains, and refuelling stations is a hard task. Difficulties may rise essentially in the choice of the optimal configurations. An innovative design of hydrogen network has been proposed in this paper. It consists of a network of green hydrogen refuelling stations (GHRSs) and several production nodes. The proposed model has been formulated as a mathematical programming, where the main decisions are the selection of GHRSs that are powered by the production nodes based on distance and population density criteria, as well the energy and hydrogen flows exchanged among the system components from the production nodes to the demand points. The approaches and methodologies developed can be taken as a support to decision makers, stakeholders and local authorities in the implementation of new hydrogen infrastructures. Optimal configurations have been reported taking into account the presence of an additional hydrogen industrial market demand and a connection with the electrical network. The main challenge that has been treated within the paper is the technical feasibility of the hydrogen supply chain, that is mainly driven by uncertain, but clean solar and wind energy resources. Using a Northern Italian case study, the clean hydrogen produced can be technically considered feasible to supply a network of hydrogen refuelling stations. Results show that the demands are satisfied for each time period and for the market penetration scenarios adopted.     

The implementation of the EU renewable directive in Spain. Strategies and challenges

Based on the European project RES2020, the analysis evaluates the energy strategies to be implemented in Spain in order to satisfy the EU Renewable Directive. The modelling framework relies on the technico-economic model TIMES-Spain, part of the Pan-European TIMES model used in the project. TIMES is a bottom-up technology rich optimisation model representing the whole energy systems of the countries. Among the results, it appears that the gap regarding the renewable deployment in Spain between the Business-as-Usual case (including the existing policies) and the EU Directive should be compensated mainly by the penetration of bioenergy in transport and industry, and by the implementation of conservation measures, which contribute to reduce the total energy demand and thus makes useless additional investments in renewable power plants compared to the Business-as-Usual case. Only higher climate mitigation ambitions result in an absolute increase in the renewable-based electricity generation compared to the Business-as-Usual case. Moreover, when allowed, Spain is offering renewable energy credits under the statistical transfer mechanism to other European countries. The cost increase of the modelled renewable and climate policies compared to the Business-as-Usual remains relatively minor.     

Optimal sizing study of hybrid wind/PV/diesel power generation unit

In this paper, a methodology of sizing optimization of a stand-alone hybrid wind/PV/diesel energy system is presented. This approach makes use of a deterministic algorithm to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the total cost of the system is minimized while guaranteeing the availability of the energy. The collection of 6 months of data of wind speed, solar radiation and ambient temperature recorded for every hour of the day were used. The mathematical modeling of the main elements of the hybrid wind/PV/diesel system is exposed showing the more relevant sizing variables. A deterministic algorithm is used to minimize the total cost of the system while guaranteeing the satisfaction of the load demand. A comparison between the total cost of the hybrid wind/PV/diesel energy system with batteries and the hybrid wind/PV/diesel energy system without batteries is presented.The reached results demonstrate the practical utility of the used sizing methodology and show the influence of the battery storage on the total cost of the hybrid system.     

欧盟能源转型的路径及对我国的启示

欧盟在发展低碳经济的背景下通过制定具体且严格的温室气体减排和可再生能源发展目标,大力推广各种低碳能源技术的应用,积极倡导低碳化的能源转型。欧盟能源转型的理念和行动已成为各国制定能源政策的重要参考,并引领了当前全球能源转型的主流发展方向。本文在对欧盟各国能源转型战略进行梳理的基础上,归纳了各国能源转型的核心及关键措施,分析了欧盟低碳能源发展迅速的主要原因,并总结了欧盟能源转型对我国推进能源生产和消费革命的启示。     

Putting renewables and energy efficiency to work: How many jobs can the clean energy industry generate in the US?

An analytical job creation model for the US power sector from 2009 to 2030 is presented. The model synthesizes data from 15 job studies covering renewable energy (RE), energy efficiency (EE), carbon capture and storage (CCS) and nuclear power. The paper employs a consistent methodology of normalizing job data to average employment per unit energy produced over plant lifetime. Job losses in the coal and natural gas industry are modeled to project net employment impacts. Benefits and drawbacks of the methodology are assessed and the resulting model is used for job projections under various renewable portfolio standards (RPS), EE, and low carbon energy scenarios We find that all non-fossil fuel technologies (renewable energy, EE, low carbon) create more jobs per unit energy than coal and natural gas. Aggressive EE measures combined with a 30% RPS target in 2030 can generate over 4 million full-time-equivalent job-years by 2030 while increasing nuclear power to 25% and CCS to 10% of overall generation in 2030 can yield an additional 500,000 job-years.     

Dynamic planning,conversion, and management strategy of different renewable energy sources: A Sustainable Solution for Severe Energy Crises in Emerging Economies

Green hydrogen energy is a natural substitute for fuel-based energy and it increases a country's long-term energy safety. Pakistan has been a victim of a severe energy crisis for the past few decades. In this context, this research addresses green hydrogen generation and renewable energy supply (i.e., wind, solar, biomass, public waste, geothermal and small hydropower) as an alternate energy source in Pakistan. The assessment is carried out through a two-step framework (i.e., Fuzzy-AHP and non-parametric DEA). Results show that Pakistan has abundant renewable power capacity from wind, which the light-duty transport in the country can opt. Almost 4.89 billion gallons of fuel are consumed annually in Sindh, whereas Punjab uses up around 6.92 billion gallons of fuel annually, which need to be substituted with 1.63 billion kg and 2.31 billion kg of wind-produced hydrogen, respectively. It has been discovered that solar and wind energy attain the same criterion of weights (i.e., 0.070) in-line with the commercial potential criterion. Besides, wind-generated power is ideal for green hydrogen generation in Pakistan, and the subsequent choice for green hydrogen energy is small hydropower and solar, which are also good for green hydrogen generation in the country. Hence, this research offers a solid recommendation for the use of wind energy, which is ideal for the production of Green Hydrogen energy in the country.     

Techno-economic optimization of wind energy based hydrogen refueling station case study Salalah city Oman

Clean energy resources will be used more for sustainability improvement and durable development. Efficient technologies of energy production, storage, and usage results in reduction of gas emissions and improvement of the world economy. Despite 30% of electricity being produced from wind energy, the connection of wind farms to medium and large-scale grid power systems is still leading to instability and intermittency problems. Therefore, the conversion of electrical energy generated from wind parks into green hydrogen consists of an exciting solution for advancing the development of green hydrogen production, and the clean transportation sector. This paper presents a techno-economic optimization of hydrogen production for refueling fuel cell vehicles, using wind energy resources. The paper analyses three configurations, standalone Wind-Park Hydrogen Refueling Station (WP-HRS) with backup batteries, WP-HRS with backup fuel cells, and grid-connected WP-HRS. The analysis of different configurations is based on the wind potential at the site, costs of different equipment, and hydrogen load. Therefore, the study aims to find the optimized capacity of wind turbines, electrolyzers, power converters, and storage tanks. The optimization results show that the WP-HRS connected to the grid has the lowest Present Worth Cost (PWC) of 6,500,000 €. Moreover, the Levelized Hydrogen Cost (LHC) of this solution was found to be 6.24 €/kg. This renewable energy system produces 80,000 kg of green hydrogen yearly.     

Optimization of energy production system in the Dodecanese Islands

The ongoing depletion of the fossil fuels and the dependency of the economies on them have made the need for new sources of energy more obvious. Renewable energy sources (RES) can ensure the sustainable development of the communities, and especially of those in which RES are in abundance. This study deals with the exploitation of RES in the Dodecanese Islands. Specifically, it is examined the optimum percentage by which the renewable sources can participate in the energy production system. Three different scenarios are examined. The first scenario considers that the existent system should be used less than 75% for environmental reasons, in the second scenario, a minimization of the electricity production cost is sought without any environmental constraints, while in the third scenario, it is considered that the RES’ participation in the electricity production would be 30% at most according to the current legislation. The environmental impacts from the energy production are quantified and a comparison is made between the impacts resulting from the existing system and the system found from the first scenario, because this is the scenario with the highest penetration of the RES to the energy production system.