Hydrogen production for energy: An overview

In this paper, a new multi-criteria problem solving method—the Full Consistency Method (FUCOM)—is proposed. The model implies the definition of two groups of constraints that need to satisfy the optimal values of weight coefficients. The first group of constraints is the condition that the relations of the weight coefficients of criteria should be equal to the comparative priorities of the criteria. The second group of constraints is defined on the basis of the conditions of mathematical transitivity. After defining the constraints and solving the model, in addition to optimal weight values, a deviation from full consistency (DFC) is obtained. The degree of DFC is the deviation value of the obtained weight coefficients from the estimated comparative priorities of the criteria. In addition, DFC is also the reliability confirmation of the obtained weights of criteria. In order to illustrate the proposed model and evaluate its performance, FUCOM was tested on several numerical examples from the literature. The model validation was performed by comparing it with the other subjective models (the Best Worst Method (BWM) and Analytic Hierarchy Process (AHP)), based on the pairwise comparisons of the criteria and the validation of the results by using DFC. The results show that FUCOM provides better results than the BWM and AHP methods, when the relation between consistency and the required number of the comparisons of the criteria are taken into consideration. The main advantages of FUCOM in relation to the existing multi-criteria decision-making (MCDM) methods are as follows: (1) a significantly smaller number of pairwise comparisons (only n − 1), (2) a consistent pairwise comparison of criteria, and (3) the calculation of the reliable values of criteria weight coefficients, which contribute to rational judgment.

https://www.mdpi.com/2073-8994/10/9/393/pdf

A New Model for Determining Weight Coefficients of Criteria in MCDM Models: Full Consistency Method (FUCOM)

Floods are natural disasters with significant socio-economic consequences Urban areas with uncontrolled urban development, rapid population growth, an unregulated municipal system and an unplanned change of land use belong to the highly sensitive areas where floods cause devastating economic and social losses The aim of this paper is to present a reliable GIS multi-criteria methodology for hazard zones’ mapping of flood-prone areas in urban areas The proposed methodology is based on the combined application of geographical information systems (GIS) and multi-criteria decision analysis (MCDA) The methodology considers six factors that are relevant to the hazard of flooding in urban areas: the height, slope, distance to the sewage network, the distance from the water surface, the water table and land use The expert evaluation takes into account the nature and severity of observed criteria, and it is tested using three scenarios: the modalities of the analytic hierarchy process (AHP) The first of them uses a new approach to the exploitation of uncertainty in the application of the AHP technique, the interval rough numbers (IR’AHP) The second one uses the fuzzy technique for the exploitation of uncertainty with the AHP method (F’AHP), and the third scenario contemplates the use of the traditional (crisp) AHP method The proposed methodology is demonstrated in Palilula Municipality, Belgrade, Serbia In the last few decades, Palilula Municipality has been repeatedly devastated by extreme flood events These floods severely affected the transportation networks and other infrastructure Historical flood inundation data have been used in the validation process The final urban flood hazard map proves a satisfactory agreement between the flood hazard zones and the spatial distribution of historical floods that happened in the last 58 years The results indicate that the scenario in which the IR’AHP methodology is used provides the highest level of compatibility with historical data on floods The produced map showed that the areas of very high flood hazard are located on the left Danube River bank These areas are characterized by lowland morphology, gentle slope, sewage network, expansion of impermeable locations and intense urbanization The proposed GIS-IR’AHP methodology and the results of this study provide a good basis for developing a system of flood hazard management in urban areas and can be successfully used for spatial city development policy

Application of GIS-Interval Rough AHP Methodology for Flood Hazard Mapping in Urban Areas

The climate changes that are becoming visible today are a challenge for the global research community. The stationary applications sector is one of the most important energy consumers. Harnessing the potential of renewable energy worldwide is currently being considered to find alternatives for obtaining energy by using technologies that offer maximum efficiency and minimum pollution. In this context, new energy generation technologies are needed to both generate low carbon emissions, as well as identifying, planning and implementing the directions for harnessing the potential of renewable energy sources. Hydrogen fuel cell technology represents one of the alternative solutions for future clean energy systems. This article reviews the specific characteristics of hydrogen energy, which recommends it as a clean energy to power stationary applications. The aim of review was to provide an overview of the sustainability elements and the potential of using hydrogen as an alternative energy source for stationary applications, and for identifying the possibilities of increasing the share of hydrogen energy in stationary applications, respectively. As a study method was applied a SWOT analysis, following which a series of strategies that could be adopted in order to increase the degree of use of hydrogen energy as an alternative to the classical energy for stationary applications were recommended. The SWOT analysis conducted in the present study highlights that the implementation of the hydrogen economy depends decisively on the following main factors: legislative framework, energy decision makers, information and interest from the end beneficiaries, potential investors, and existence of specialists in this field.

https://www.mdpi.com/1996-1073/12/23/4593/pdf

Hydrogen Fuel Cell Technology for the Sustainable Future of Stationary Applications

Trends in design of distributed energy systems using hydrogen as energy vector: A systematic literature review

Nowadays, the evolution of solar energy use has turned into a profound issue because of the implications of many points of view, such as technical, social, economic and environmental that impose major constraints for policy-makers in optimizing solar energy alternatives. The topographical constraints regarding the availability of inexhaustible solar energy is driving field development and highlights the need for increasingly more complex solar power systems. The solar energy is an inexhaustible source of CO2 emission-free energy at a global level. Solar thermal technologies may produce electric power when they are associated with thermal energy storage, and this may be used as a disposable source of limitless energy. Furthermore, it can also be used in industrial processes. Using these high-tech systems in a large area of practice emboldens progress at the performance level. This work compiles the latest literature in order to provide a timely review of the evolution and worldwide implementation of Concentrated Solar Power—CSP—mechanization. The objective of this analysis is to provide thematic documentation as a basis for approaching the concept of a polygeneration solar system and the implementation possibilities. It also aims to highlight the role of the CSP in the current and future world energy system.

https://www.mdpi.com/1996-1073/12/6/1048/pdf

Concentrating Solar Power Technologies

Choosing the Optimal Technology to Rehabilitate the Pipes in Water Distribution Systems Using the AHP Method

Since mid 2010, petrol consumption in the transport sector has increased at a higher rate than in other sectors. The transport sector generates 35% of the total CO2 emissions. In this context, strategies have been adopted to use clean energy, with electromobility being the main directive. This paper examines the possibility of charging electric vehicle batteries with clean energy using solar autochthonous renewable resources. An isolated system was designed, dimensioned, and simulated in operation for a charging station for electric vehicles with photovoltaic panels and batteries as their main components. The optimal configuration of the photovoltaic system was complete with improved Hybrid Optimization by Genetic Algorithms (iHOGA) software version 2.4 and we simulated its operation. The solar energy system has to be designed to ensure that the charging station always has enough electricity to supply several electric vehicles throughout all 24 h of the day. The main results were related to the energy, environmental, and economic performance achieved by the system during one year of operation.

https://www.mdpi.com/1996-1073/12/1/74/pdf

Design and Simulation of Romanian Solar Energy Charging Station for Electric Vehicles

Hydrogen Production Using Solar Energy - Technical Analysis☆

This paper aims to present partial results of a large study regarding the alternative energen solutions (sun, wind, hydrogen) for power supply of passive house placed on Cluj-Napoca, Romania. Five scenarios for different combinations were optimized and analyzed of hybrid energy system. The best energy and environmental performances are achieved by hydrogen technology and fuel cell, also the use of hydrogen energy is more efficient and less expensive then primary renewable energy seasonal storage by batteries.

Gheorghe Badea

Papers

Concentrating Solar Power Technologies

Choosing the Optimal Technology to Rehabilitate the Pipes in Water Distribution Systems Using the AHP Method

Design and Simulation of Romanian Solar Energy Charging Station for Electric Vehicles

Hydrogen Production Using Solar Energy - Technical Analysis☆

Energen System for Power Supply of Passive House: Case Study