Application of normal wiggly dual hesitant fuzzy sets to site selection for hydrogen underground storage

The hesitant fuzzy set is a mathematical tool to express multiple values in decision making. If they could not give a resolution, it is important to give priority and importance to a number of different values. Here, we propose normal wiggly dual hesitant fuzzy set (NWDHFS), as an extension of normal wiggly hesitant fuzzy set. We define a new score function of normal wiggly dual hesitant fuzzy information. The NWDHFS can express deep ideas of membership and non-membership information. In this work, we use hesitant fuzzy set to expose the deepest ideas hidden in the thought-level of the decision makers. We show that the NWDHFS can handle the hesitant fuzzy information. It expresses the deeper ideas of hesitant fuzzy set. An illustration is provided to demonstrate the practicality and effectiveness to the application of site selection of the underground storage of hydrogen. We are compelled to look for alternating fuels to suits changing weather conditions and increasing number of vehicles. This alternative fuel is necessary to control global warming and to be economically viable. Based on this, hydrogen gas is selected as a good alternative fuel. The most important statement is the saving of the selected hydrogen gas. Thus, when saving hydrogen fuel, a safe storage space must be selected. Here, we use the MCDM ideas by use of proposed NWDHFV method is to select the appropriate hydrogen underground storage location.     

Multidimensional evaluation of global investments on the renewable energy with the integrated fuzzy decision‐making model under the hesitancy

This study aims to assess global investment alternatives with respect to renewable energy. Within this framework, five different renewable energy types (biomass, hydropower, geothermal, wind, and solar) are determined as investment alternatives. Moreover, eight different criteria are selected by considering the four different dimensions of balanced scorecard. Additionally, the fuzzy‐based decision making trial and the evaluation laboratory under the hesitancy (HF‐DEMATEL) model are taken into the account to weight these dimensions and criteria and the technique for order the preferences by the similarity to the ideal solution with the fuzzy hesitant methodology (HF‐TOPSIS) is considered to select the alternatives of renewable energy investments. The novelties of this study are to propose an integrated model and provide the balanced scorecard–based evaluations of global renewable energy investment alternatives. The findings show that learning and growth and customer are the most important dimensions for the investment on renewable energy. It is also identified that market potential, product customization, and technological development are the most significant criteria for this situation. On the other side, solar and wind energy are the most important renewable investment alternatives. These results explain that technological improvement should be maintained, and customer expectations should be met by the companies. Furthermore, solar power plant and wind power plant should be developed in the countries. For this purpose, governments should give necessary incentives to the investors, such as allocating appropriate lands. These actions can attract the attentions of the potential investors for these renewable energy alternatives. Owing to this issue, it can be possible to increase the capacity of electricity productions in the countries with a potential minimum cost.     

Comparative fuel cell sustainability assessment with a novel approach

Fuel cells have been attracting many researchers and industry partners' attention due to their clean, quiet, modular, and flexible operation characteristics. As Power-to-Gas technologies evolve and get more sustainable, well-developed fuel cells will be needed to convert the chemical energy stored in the gas form to useful products such as power and heat. For that reason, a comprehensive sustainability investigation of fuel cells is conducted by taking their economic, environmental, social, and technical performance into account. The selected fuel cells are polymer electrolyte membrane, alkaline, phosphoric acid, molten carbonate, and solid oxide. These fuel cells’ performance is comparatively investigated based on four primary and 15 sub-criteria. The selected performance criteria are economic (initial and running costs), environmental (GHG emissions, land use, solid waste generation, and water discharge quality), social (employment and training opportunities, impact on public health, and public acceptance), and technical (energy and exergy efficiencies, process control, start-up time, and scalability). This study is the first in the literature to conduct an in-detail and very inclusive sustainability evaluation of fuel cells. It is expected to guide many professionals from academia and industry towards developing cleaner, safer, more affordable, and efficient fuel cells.     

General sustainability indicator of renewable energy system based on grey relational analysis

This research answers the question of how to measure the sustainability of a renewable energy systems (RESs) as a physical parameter. Renewable energy is considered as a solution for mitigating the energy crisis, climate change and environmental pollution; however, an important problem of its application is that it is very difficult to evaluate the sustainability of RESs. This study develops a general sustainability indicator which is a tool to evaluate sustainability of RESs precisely and comprehensively. Based on the Triple Bottom Line approach, 11 Basic Sustainability Indicators with different dimensions and various units are selected from environmental, economic and social sustainability assessment criteria. In order to deal with the uncertainties in the definition and the assessment of sustainability, the grey regression analysis method is employed to quantify the basic indicators and to aggregate them into the general indicator. In addition, for explaining application of the general indicator, the cases of four RESs in hot‐arid Australia are presented. In the case study, the grey indicator is used to assess the sustainability of four systems with different combinations of grid, solar photovoltaic and wind renewable energy. The final results are compared with the general indicator based on fuzzy sets theory developed in previous studies. It is found that for the case of Australian system, the grey sustainability indicator has a good linear correlation to the fuzzy indicator results. The grey indicator is an effective way to assess the sustainability of RESs and provides a good tool for designers, users, decision makers and researchers. Copyright © 2013 John Wiley & Sons, Ltd.     

Review on multi-criteria decision analysis aid in sustainable energy decision-making

Multi-criteria decision analysis (MCDA) methods have become increasingly popular in decision-making for sustainable energy because of the multi-dimensionality of the sustainability goal and the complexity of socio-economic and biophysical systems. This article reviewed the corresponding methods in different stages of multi-criteria decision-making for sustainable energy, i.e., criteria selection, criteria weighting, evaluation, and final aggregation. The criteria of energy supply systems are summarized from technical, economic, environmental and social aspects. The weighting methods of criteria are classified into three categories: subjective weighting, objective weighting and combination weighting methods. Several methods based on weighted sum, priority setting, outranking, fuzzy set methodology and their combinations are employed for energy decision-making. It is observed that the investment cost locates the first place in all evaluation criteria and CO₂ emission follows closely because of more focuses on environment protection, equal criteria weights are still the most popular weighting method, analytical hierarchy process is the most popular comprehensive MCDA method, and the aggregation methods are helpful to get the rational result in sustainable energy decision-making.     

The role of hydrogen and fuel cells to store renewable energy in the future energy network – potentials and challenges

The penetration of renewable energy sources is expected to rapidly increase from 15% to 50% in 2050 due to their vital contribution to the global energy requirements, sustainability and quality of life in economical, environmental and health aspects. This huge rise highlights the necessity of development of energy storage systems, especially for intermittency renewable energies such as solar photovoltaic and wind turbine, in order to balance the energy network. In this study, renewable energy options including pumped hydro, pressurized air, flywheels, Li ion batteries, hydrogen and super-capacitors are compared based on a specific set of criteria. The criteria considered are energy/power density, ease of integration with the existing energy network, cost effectiveness, durability, efficiency and safety. Our study showed that storing renewable energy sources in the form of hydrogen through the electrolysis process is ranked as the most promising option considering the mentioned criteria. It brings about several benefits suggesting that hydrogen and fuel cells are promising contributors towards a more sustainable future, both in energy demand and environmental sustainability.     

Hybridized off-grid fuel cell/wind/solar PV /battery for energy generation in a small household: A multi-criteria perspective

In this paper, the robust capability of HOMER and Criteria-COPRAS is deployed to explore the prospect of selecting a renewable energy system. The energy system consisting of wind turbines, solar photovoltaic (PV), fuel cell (FC), electrolyzer, hydrogen storage, and battery energy storage is intended to power a residential load in Lagos Nigeria. Based on the economic metric, the results show that the optimal system is a PV-Battery whose total net present cost (TNPC) and initial investment cost are $9060 and $3,818, respectively. However, if the energy systems are ranked based on multiple criteria (economic, technical and environmental aspects), the most preferred of the feasible energy systems is a hybrid PV-FC-wind-battery (TNPC-$10,324, initial cost: $7670). The study results indicate that, for viability in the adoption of hydrogen energy storage as part of the hybrid energy system, the selection metric should be based on more than one criterion.     

Developing a novel fuzzy neutrosophic numbers based decision making analysis for prioritizing the energy storage technologies

The energy storage plays a fundamental role for sustainable energy systems and potential future economy. The aim of this study is to evaluate and prioritize the energy storage technology alternatives (methods) considering technical, cost, and environmental and social criteria. We propose a hybrid trapezoidal neutrosophic fuzzy numbers based Dombi weighted geometric averaging operator and MultiAtributive Ideal-Real Comparative Analysis (MAIRCA) model. A case study in Romania is carried out to demonstrate the applicability of the proposed model. It is also compared with some existing methods to verify the superiority of the proposed model. Six technical storage methods are examined as follows: A₁: Hydro-pumping (HP), A₂: Hydrogen Underground Storage (HU), A₃: Hydrogen “on ground” multiple storage solution (HM), A₄: Hybrid 1 (HP + HU), A₅: Hybrid 2 (HP + HM), and A₆: Hybrid 3 (HU + HM). The results show that the alternative A₄: hydro-pumping and hydrogen underground storage method is the best among all alternatives.     

A review on clean energy solutions for better sustainability

This paper focuses on clean energy solutions in order to achieve better sustainability, and hence discusses opportunities and challenges from various dimensions, including social, economic, energetic and environmental aspects. It also evaluates the current and potential states and applications of possible clean‐energy systems. In the first part of this study, renewable and nuclear energy sources are comparatively assessed and ranked based on their outputs. By ranking energy sources based on technical, economic, and environmental performance criteria, it is aimed to identify the improvement potential for each option considered. The results show that in power generation, nuclear has the highest (7.06/10) and solar photovoltaic (PV) has the lowest (2.30/10). When nonair pollution criteria, such as land use, water contamination, and waste issues are considered, the power generation ranking changes, and geothermal has the best (7.23/10) and biomass has the lowest performance (3.72/10). When heating and cooling modes are considered as useful outputs, geothermal and biomass have approximately the same technical, environmental, and cost performances (as 4.9/10), and solar has the lowest ranking (2/10). Among hydrogen production energy sources, nuclear gives the highest (6.5/10) and biomass provides the lowest (3.6/10) in ranking. In the second part of the present study, multigeneration systems are introduced, and their potential benefits are discussed along with the recent studies in the literature. It is shown that numerous advantages are offered by renewable energy‐based integrated systems with multiple outputs, especially in reducing overall energy demand, system cost and emissions while significantly improving overall efficiencies and hence output generation rates. Copyright © 2015 John Wiley & Sons, Ltd.     

Towards a sustainable hydrogen economy: A multi-criteria sustainability appraisal of competing hydrogen futures

The ‘hydrogen economy’ has the potential to provide a sustainable and secure energy system, and there is a wide and growing literature promoting and exploring different possible hydrogen futures. However, despite broad agreement that hydrogen could make a significant contribution to energy policy goals, the literature exhibits strong disagreements about the form that a future hydrogen economy should take. Visions of the future select, combine and reconfigure individual hydrogen generation, storage, transport and end-use technologies into more or less mutually compatible energy and transportation systems, which embody deeply contested and conflicting views of sustainability.

This paper describes the application of a novel foresight methodology, which combined participatory scenario development, using a backcasting approach, with an expert-stakeholder multi-criteria mapping (MCM) process, in order to provide an integrated, transparent assessment of the environmental, social and economic sustainability of six possible future hydrogen energy systems for the UK. The findings suggest that: hydrogen has the potential to deliver substantial sustainability benefits over the status quo, or, business as usual, futures, but that hydrogen is not automatically a sustainable option; carbon emissions are the single most important dimension of sustainability, but that issues other than carbon and cost need to be considered if hydrogen is truly to deliver greater sustainability. Furthermore, there was significant disagreement about which visions were considered more or less sustainable. These findings reflect two important sources of divergence in the final sustainability rankings: uncertainties and contested views of sustainability.     

Towards integrated sustainability assessment for energetic use of biomass: A state of the art evaluation of assessment tools

Biomass is expected to play an increasingly significant role in the ‘greening’ of energy supply. Nevertheless, concerns are rising about the sustainability of large-scale energy crop production. Impacts must be assessed carefully before deciding whether and how this industry should be developed, and what technologies, policies and investment strategies should be pursued. There is need for a comprehensive and reliable sustainability assessment tool to evaluate the environmental, social and economic performance of biomass energy production. This paper paves the way for such a tool by analysing and comparing the performance and applicability of a selection of existing tools that are potentially useful for sustainability assessment of bioenergy systems. The selected tools are: Criteria And Indicators (C&I), Life Cycle Assessment (LCA), Environmental Impact Assessment (EIA), Cost Benefit Analysis (CBA), Exergy Analysis (EA) and System Perturbation Analysis (SPA). To evaluate the tools, a framework was constructed that consists of four evaluation levels: sustainability issues, tool attributes, model structure, area of application. The tools were then evaluated using literature data and with the help of a Delphi panel of experts. Finally, a statistical analysis was performed on the resulting data matrix to detect significant differences between tools. It becomes clear that none of the selected tools is able to perform a comprehensive sustainability assessment of bioenergy systems. Every tool has its particular advantages and disadvantages, which means that trade-offs are inevitable and a balance must be found between scientific accuracy and pragmatic decision making. A good definition of the assessment objective is therefore crucial. It seems an interesting option to create a toolbox that combines procedural parts of C&I and EIA, supplemented with calculation algorithms of LCA and CBA for respectively environmental and economic sustainability indicators. Nevertheless, this would require a more comprehensive interdisciplinary approach to align the different tool characteristics and focuses.     

Life cycle assessment (LCA) and life cycle cost (LCC) analysis model for a stand-alone hybrid renewable energy system

Nowadays the biggest challenge for most organizations is a real and substantial application of sustainability through the measurement and comparability of results in order to satisfy the principles of sustainability of all the stakeholders. Definitively, it is necessary to pursue sustainability through the measurements of specific indicators and control the variables that influence the state of the economic, social and environmental issues. The aim of this paper is to contribute to the development of a comprehensive, yet practical and reliable tool for a systematic sustainability assessment, based on the Life Cycle Assessment (LCA) and the Analytic Hierarchy Process (AHP) to support decision makers in complex decision problems in the field of environmental sustainability. The results are applied to a novel compressed air energy storage system proposed as a suitable technology for the energy storage in a small scale stand-alone renewable energy power plant (photovoltaic power plant) that is designed to satisfy the energy demand of a radio base station for mobile telecommunications. The outcome is a dynamic analysis and iterative integrated sustainability assessment of corporate performance.     

Micro-grid design and life-cycle assessment of a mountain hut's stand-alone energy system with hydrogen used for seasonal storage

Mountain huts, as special, stand-alone, micro-grid systems, are not connected to a power grid and represent a burden on the environment. The micro-grid has to be flexible to cover daily and seasonal fluctuations. Heat and electricity are usually generated with fossil fuels due to the simple on-off operation. By introducing renewable energy sources (RESs), the generation of energy could be more sustainable, but the generation and consumption must be balanced. The paper describes the integration of a hydrogen-storage system (HSS) and a battery-storage system (BattS) in a mountain hut. The HSS involves a proton-exchange-membrane water electrolyser (PEMWE), a hydrogen storage tank (H₂ tank), a PEM fuel cell (PEMFC) and a BattS consisting of lead-acid batteries. Eight micro-grid configurations were modelled using HOMER and evaluated from the technical, environmental and economic points of view. A life-cycle assessment analysis was made from the cradle to the gate. The micro-grid configurations with the HSS achieve, on average, a more than 70% decrease in the environmental impacts in comparison to the state of play at the beginning, but require a larger investment. Comparing the HSS with the BattS as a seasonal energy storage, the hydrogen-based technology had advantages for all of the assessed criteria.     

Site selection for hydrogen underground storage using interval type-2 hesitant fuzzy sets

This study presents an interval type-2 hesitant fuzzy set (IT2HFS) based multi-criteria decision making (MCDM) method for selecting hydrogen underground storage sites in Turkey. The proposed method is utilized in a case study that aims to determine the best site among three alternatives. The results show that the proposed method can effectively and flexibly handle the interval type-2 hesitant fuzzy MCDM site selection problems. Finally, the sensitivity analysis is also demonstrated for the proposed method.     

The Lebanese electricity system in the context of sustainable development

The Lebanese electricity system has been evaluated in terms of its sustainability. An integrated approach was adopted to assess the life-cycle technical, environmental, energy and economic attributes of the system. The findings show that the Lebanese electricity system is characterized by a weak performance in all analysed aspects related to the sustainability of energy systems. Specifically, the system lacks adequacy and security leading to a supply–demand deficit and poor diversity. It gives rise to significant environmental emissions (including green-house gases), and produces large economic inefficiencies. The costs and benefits of optimising the performance of the centralised electricity system are presented, indicating substantial net benefits (together with considerable benefits in reduced environmental impacts across the life-cycle assessment categories, including carbon emissions) from improving the transmission and distribution networks, upgrading existing conventional plants to their design standards, and shifting towards the use of natural gas. The expected levelised cost of various energy sources in Lebanon also indicates that renewable energy sources are competitive alternatives at the present time.     

Life cycle sustainability assessment of hydrogen from biomass gasification: A comparison with conventional hydrogen

Hydrogen is a key product for a cleaner energy sector. However, the suitability of the different hydrogen production options should be checked from a life-cycle perspective. The Life Cycle Sustainability Assessment (LCSA) methodology is helpful for this purpose, allowing a thorough interpretation of a product system's performance by integrating economic, environmental and social indicators. This work presents an LCSA of renewable hydrogen from biomass gasification, and its sustainability benchmarking against conventional hydrogen from steam methane reforming. Environmental (global warming and acidification), economic (levelised cost) and social (child labour, gender wage gap, and health expenditure) life-cycle indicators are characterised and jointly interpreted. The results show that hydrogen from biomass gasification cannot yet be thoroughly considered a sustainable alternative to conventional hydrogen mainly due to economic and social concerns. However, improvement actions leading to an increase in process efficiency would significantly enhance the system's performance in each of the three sustainability dimensions.     

Assessment of hydrogen production methods via integrated MCDM approach under uncertainty

Energy has a crucial role for the existence and social well-being of human. Among various options, hydrogen is the promising energy carrier for sustainable energy systems. As an important source of hydrogen, Hydrogen Sulphide (H₂S) is abundantly found in Black Sea waters and known as an environmental pollutant. The main aim of this study is to evaluate Thermochemical, Electrochemical, Thermal, Photochemical, Plasma, and Thermal methods as decomposition methods, which meet sustainability aspects better than other technologies, based on expert opinions. As sustainable criteria, economically feasibility, ecologically feasibility, efficiency, process simplicity, energy requirement, safety and reliability, applicability and operational suitability and technical maturity are considered to determine the most appropriate hydrogen production method. In this sense, we have suggested a new integrated Multi-Criteria-Decision-Making (MCDM) methodology consisting of stepwise weight assessment ratio analysis (SWARA) with fuzzy set theory (FST) and Weighted Aggregated Sum Product Assessment (WASPAS) by employing interval valued intuitionistic fuzzy sets (IVIFS) in the selection process. The contribution of the study is not only proposing a new method which hybridizes the SWARA and WASPAS under uncertainty but also selecting the most sustainable Hydrogen production method utilizing from H₂S in the Black Sea in Turkey, considering sustainable criteria which are unavoidable in energy management problems. At the end, the results are discussed, and sensitivity and comparative analyses are utilized to check the robustness and feasibility of solutions. Consequently, electrochemical is selected as the best and most appropriate hydrogen production method in terms of providing high efficiency in conversion and sustainable processes, i.e handling, transporting and storing harmful chemicals.     

Sustainability assessment of hydrogen energy systems

This paper gives an overview of the potential on multi-criteria assessment of hydrogen systems. With respective selection of the criteria comprising performance, environment, market and social indicators the assessment procedure is adapted for the assessment of the selected options of the hydrogen energy systems and their comparison with new and renewable energy systems.The single parameter assessment for each indicator is demonstrated as the traditional approach in the evaluation of the option under consideration which reflects a biased result depending on the selected indicator. In order to apply the multi-criteria approach to the hydrogen systems, it was necessary to use the multi-criteria procedure based on the sustainability index rating composed of linear aggregative functions of all indicators with respective weighting function.The example under consideration are hydrogen fuel cell systems with three options including natural gas turbine, photovoltaic and wind energy systems representing different renewable power plant option. These options are evaluated with the multi-criteria method comprising the following indicators: performance indicator, market indicator, environment indicator and social indicator. The indicators are composed of a number of sub-indicators agglomerated in respective indicators. The evaluation of options under consideration was performed under constraint expressing non-numeric relation among the indicators. The group comprises cases when priority is given to a single indicator and other indicators have the same value.     

Hydrogen-based systems for integration of renewable energy in power systems: Achievements and perspectives

This paper is a critical review of selected real-world energy storage systems based on hydrogen, ranging from lab-scale systems to full-scale systems in continuous operation. 15 projects are presented with a critical overview of their concept and performance. A review of research related to power electronics, control systems and energy management strategies has been added to integrate the findings with outlooks usually described in separate literature. Results show that while hydrogen energy storage systems are technically feasible, they still require large cost reductions to become commercially attractive. A challenge that affects the cost per unit of energy is the low energy efficiency of some of the system components in real-world operating conditions. Due to losses in the conversion and storage processes, hydrogen energy storage systems lose anywhere between 60 and 85% of the incoming electricity with current technology. However, there are currently very few alternatives for long-term storage of electricity in power systems so the interest in hydrogen for this application remains high from both industry and academia. Additionally, it is expected that the share of intermittent renewable energy in power systems will increase in the coming decades. This could lead to technology development and cost reductions within hydrogen technology if this technology is needed to store excess renewable energy. Results from the reviewed projects indicate that the best solution from a technical viewpoint consists in hybrid systems where hydrogen is combined with short-term energy storage technologies like batteries and supercapacitors. In these hybrid systems the advantages with each storage technology can be fully exploited to maximize efficiency if the system is specifically tailored to the given situation. The disadvantage is that this will obviously increase the complexity and total cost of the energy system. Therefore, control systems and energy management strategies are important factors to achieve optimal results, both in terms of efficiency and cost. By considering the reviewed projects and evaluating operation modes and control systems, new hybrid energy systems could be tailored to fit each situation and to reduce energy losses.     

Selection criteria and ranking for sustainable hydrogen production options

This paper aims to holistically study hydrogen production options essential for a sustainable and carbon-free future. This study also outlines the benefits and challenges of hydrogen production methods to provide sustainable alternatives to fossil fuels by meeting the global energy demand and net-zero targets. In this study, sixteen hydrogen production methods are selected for sustainability investigation based on seven different criteria. The criteria selected in the comparative evaluation cover various dimensions of hydrogen production in terms of economic, technical, environmental, and thermodynamic aspects for better sustainability. The current study results show that steam methane reforming with carbon capture could provide sustainable hydrogen in the near future while the other technologies’ maturity levels increase and the costs decrease. In the medium- and long-terms, photonic and thermal-based hydrogen production methods can be the key to sustainable hydrogen production.