Papers by J. Sánchez-Lozano
The diverse socio-economic and environmental impacts that the set-up of a new photovoltaic instal... more The diverse socio-economic and environmental impacts that the set-up of a new photovoltaic installation has must be weighed carefully in order to reach the best possible solution. Among the different photovoltaic systems there are several classification criteria, depending on the technology, application and the size of the modules that define them. The size (installed nominal capacity) stands out as an impartial and critical measure in the decision making process. In this article we use a multi-criteria decision making method to analyse the responses of five experts to a detailed questionnaire in which several different criteria are correlated with various photovoltaic installation sizes. The limitation associated to the low number of experts is addressed with a robustness and sensitivity analysis. With this study we seek first, to apply and demonstrate the feasibility of a methodology which combines technical information with multi-criteria decision making methods, and second, to o...
Scientific Reports, 2016
The impact of a near-Earth object (NEO) may release large amounts of energy and cause serious dam... more The impact of a near-Earth object (NEO) may release large amounts of energy and cause serious damage. Several NEO hazard studies conducted over the past few years provide forecasts, impact probabilities and assessment ratings, such as the Torino and Palermo scales. These high-risk NEO assessments involve several criteria, including impact energy, mass, and absolute magnitude. The main objective of this paper is to provide the first Multi-Criteria Decision Making (MCDM) approach to classify hazardous NEOs. Our approach applies a combination of two methods from a widely utilized decision making theory. Specifically, the Analytic Hierarchy Process (AHP) methodology is employed to determine the criteria weights, which influence the decision making, and the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) is used to obtain a ranking of alternatives (potentially hazardous NEOs). In addition, NEO datasets provided by the NASA Near-Earth Object Program are utilized. This approach allows the classification of NEOs by descending order of their TOPSIS ratio, a single quantity that contains all of the relevant information for each object.
Studies in Fuzziness and Soft Computing, 2015
One of the first decisions that must be made when hosting a photovoltaic solar farms to pour the ... more One of the first decisions that must be made when hosting a photovoltaic solar farms to pour the energy generated to the network is to choose a proper location (towns, existing infrastructure, etc) but also the legislative framework that is applicable since, it is involved a large number of both restrictions (protected areas, distances to streams and watercourses, etc) that will give us the guidelines to eliminate those unsuitable areas and certain criteria (proximity to power lines, slope, solar radiation, etc) according to which it will be made an evaluation of the suitable areas that condition any facility and, it is precisely for these reasons why the management of spatial visualization tools such as Geographic Information Systems (GIS) are particularly useful. The objective of this paper is to demonstrate how the aggregation of GIS to decision procedures in the field of renewable energy, can solve complex location problems. In the present case it will be appealed to the use of a GIS (called gvSIG) in order to obtain suitable locations to host photovoltaic solar farms in the Northwest of the Region of Murcia.
Computers & Industrial Engineering, 2015
The aim of the present paper is to determine the best location to host a solar thermoelectric pow... more The aim of the present paper is to determine the best location to host a solar thermoelectric power plant. We will seek to show how Geographic Information Systems (GIS) and Multi Criteria Decision Making (MCDM) such as the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS method) and Analytic Hierarchy Process (AHP), are an excellent combination to solve complex locations problems. The coast of the Region of Murcia in the southeast of Spain has been chosen as the study area to carry out this evaluation. The GIS will be shown to be a very useful tool, since GIS are able to generate a database which serves as a starting point for conducting any decision support system. The posed problem will be resolved using restrictions to reduce the area of study, and the criteria that will influence the decision-making. These criteria will be of different natures; with quantitative criteria (numerical values) coexisting with qualitative criteria (labels and linguistic variables). In this article, AHP will be used to obtain the weights of the criteria, and the fuzzy TOPSIS method for the evaluation of the alternatives. In order to compare the results obtained with TOPSIS, the ELECTRE-TRI methodology will be applied.
Spatial Analysis Using Gis for Obtaining Optimal Locations for Solar Farms, Case Study: The Northwest of the Region of Murcia Analisis Mediante Sig Para Seleccionar Emplazamientos Optimos De Huertos Solares Fotovoltaicos, Caso De Estudio: Noroeste De La Región De Murcia
One of the first decisions that must be made when hosting a photovoltaic solar farms to pour the ... more One of the first decisions that must be made when hosting a photovoltaic solar farms to pour the energy generated to the network is to choose a proper location (towns, existing infrastructure, etc) but also the legislative framework that is applicable since, it is involved a large number of both restrictions (protected areas, distances to streams and watercourses, etc) that will give us the guidelines to eliminate those unsuitable areas and certain criteria (proximity to power lines, slope, solar radiation, etc) according to which it will be made an evaluation of the suitable areas that condition any facility and, it is precisely for these reasons why the management of spatial visualization tools such as Geographic Information Systems (GIS) are particularly useful. The objective of this paper is to demonstrate how the aggregation of GIS to decision procedures in the field of renewable energy, can solve complex location problems. In the present case it will be appealed to the use of ...
Numerical Modelling of Mechanical Contact and Stress Distribution in Spot Welding for Similar Thickness Metal Plates Modelización Numérica Del Contacto Mecánico y Distribución De Tensiones en Soldadura Por Puntos Para Chapas De Metal Con Espesores Similares
This paper shows research work which is considered in the context of joint technologies, in parti... more This paper shows research work which is considered in the context of joint technologies, in particular with resistance spot welding (RSW). The welding process by electrical resistance is formed by different necessary steps in order to get a joint among two plates by electrodes. This paper is focused on the first step of the welding process, that is, in the mechanical contact prior to heating of plate by the Joule effect. In this first step several geometrical factors are studied, like the diameter of the electrode, the thickness of the plate, the applied pressure and radius wear on the electrode tip. These variables characterize the mechanical contact by the stress distribution between plate and electrode. In next papers, we will carried out with the process analysis, performing a study of transient state welding process with different roughness of plate and its influence on forge process.
Evaluation of Manufacturing Technology of Photovoltaic Cells
World Scientific Proceedings Series on Computer Engineering and Information Science, 2012
It is often advisable to combine spatial representation tools such as Geographic Information Syst... more It is often advisable to combine spatial representation tools such as Geographic Information Systems (GIS) with Multi criteria Decision Making Methods (MCDM) when solving location complex problems. The current case refers to the search for and selection of sites for onshore wind farms on the coast of the Region of Murcia, in the southeast of Spain. When resolving the proposed problem, the legal restrictions and the criteria (wind speed, area, slope, etc.) that influence the location will be considered. These will be defined in the form of thematic layers that will be entered into the GIS. Restrictions will be imposed taking into account the legislative framework of the study area so that, through their analysis and editing, it will be possible to reduce the initial area and obtain suitable sites where this type of facilities can be installed. Moreover, as the objective of the study is to select the locations and obtain a ranking two different models will be applied, initially a categorical assessment through a lexicographic order will be performed using the tools available in the GIS and, later it will be applied the ELECTRE-TRI methodology will be applied in order to make a comparison between the methods.
Decision Criteria for Optimal Location of Solar Plants: Photovoltaic and Thermoelectric
Green Energy and Technology, 2013
This chapter deals with the study and evaluation of decision criteria that should be considered f... more This chapter deals with the study and evaluation of decision criteria that should be considered for the optimal location of solar photovoltaic plants and solar thermal plants with high temperature and which are to be connected to the electricity distribution network. Criteria and subcriteria to be regarded will be of different nature, since environmental, geomorphologic, location, and strictly climatic criteria will all be considered, some of which are dependent on the technology being installed. Thus, we consider as possible alternatives the optimal locations and we will begin with a set of criteria, which must be evaluated for each of the possible alternatives for such a purpose, and includes both quantitative as well as qualitative information. As vaguely implied linguistic variables and numeric values have to be employed due to this disparity in the nature of the information, we will model the weights of the criteria by triangular fuzzy numbers. In order to reflect this and to carry out the extraction of knowledge a survey based on the fuzzy AHP methodology will be elaborated and sent to experts. In this way it will be possible to obtain the weights of the considered criteria for further evaluation of the alternatives.
Procedings of the Fourth International Workshop on Knowledge Discovery, Knowledge Management and Decision Support, 2013
In decision-making situations, it is common to have a set of alternatives and to choose the best ... more In decision-making situations, it is common to have a set of alternatives and to choose the best among them or to establish a ranking. Multi-criteria decision methods can be applied to obtain different rankings, even though the set of alternatives and criteria are the same. Considering this, the idea of Pareto analysis is discussed to process the results obtained by different methods and reach a consensus. Those alternatives that are non-dominated will be considered the best set. That reduces the number of alternatives to be chosen because only the best set of alternatives should be taking into account.
Soft Computing Applications for Renewable Energy and Energy Efficiency
In this chapter, a model that calculates the impact on the grid of the simultaneous injection of ... more In this chapter, a model that calculates the impact on the grid of the simultaneous injection of electricity both from photovoltaic and wind sources is presented. The best locations for wind and photovoltaic technologies within Región de Murcia, southeast Spain, have been selected from a GIS database and evaluated and classified using a fuzzy version of the multicriteria decision method called Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). After the classification, the best locations are selected for each technology. Then, the impact on the grid arising from the injection of power generated in wind of photovoltaic systems installed at these specific locations and that are connected to the grid has been calculated in a power range of several kWp, including random steps of up to 50kW. The results show that stable grid parameters are obtained within 500ms in all cases, even when this relatively large power surge (or variation) is considered.
Evaluation of photovoltaic cells in a multi-criteria decision making process
Annals of Operations Research, 2011
ABSTRACT The requirements to satisfy the energy needs of today without compromising those of futu... more ABSTRACT The requirements to satisfy the energy needs of today without compromising those of future generations have forced humans to adopt rules that permit a better use of the available resources, of which the sun is an inexhaustible energy source. Amongst the energy sources that offer the possibility of exploiting the resources offered by the Earth, solar energy has acquired great strength. Photovoltaic energy has presented a major evolution and it is forecasted as being an important contributor to power generation and an alternative to other non-renewable energy sources. The high cost of solar electricity is today the main reason why electricity from photovoltaic systems has not been introduced in a more widespread way. In this context, the aim of this paper is the study and analysis of the decision criteria to be used when searching for the best photovoltaic cell, studying both the criteria that exert most influence or their manufacture (defined by quantitative and qualitative values) and the alternatives which will be the decision problem to be solved; each alternative will correspond to one type of photovoltaic cell. Thus, relevant information has been provided by three experts and the TOPSIS method has been used to aggregate all the information combined with the use of fuzzy sets which will model the use of linguistic labels in the process.
Sustainability, 2016
Today, Renewable Energy Sources (RES) are a key pillar to achieving sustainable development, whic... more Today, Renewable Energy Sources (RES) are a key pillar to achieving sustainable development, which is the main reason why energy projects are being carried out not only in developed countries but also in many emerging countries. Since the technical and financial risk remains a major barrier to financing renewable energy projects, several mechanisms are available to reduce risks on investment into clean energy projects. This paper discusses risk management tools in solar photovoltaic facilities based on the guide to the Project Management (PMBOK Guide). To do this, a combination of different decision-making methodologies will be carried out. These methodologies enable to not only extract the knowledge by experts but also to know the causes and effects that help to make the best decision. In order to do so, techniques to seek information (Delphi and Checklist) as well as diagram techniques such as cause and effect diagrams or Strengths Weaknesses Opportunities and Threats (SWOT) are applied. The categorization and prioritization of risks will be carried out through the Analytic Hierarchy Process (AHP). Finally, a sensitivity analysis will allow for providing consistency to the obtained results. A real case in the Dominican Republic will also be presented as case study.
Today, Renewable Energy Sources (RES) are a key pillar to achieving sustainable development, whic... more Today, Renewable Energy Sources (RES) are a key pillar to achieving sustainable development, which is the main reason why energy projects are being carried out not only in developed countries but also in many emerging countries. Since the technical and financial risk remains a major barrier to financing renewable energy projects, several mechanisms are available to reduce risks on investment into clean energy projects. This paper discusses risk management tools in solar photovoltaic facilities based on the guide to the Project Management (PMBOK Guide). To do this, a combination of different decision-making methodologies will be carried out. These methodologies enable to not only extract the knowledge by experts but also to know the causes and effects that help to make the best decision. In order to do so, techniques to seek information (Delphi and Checklist) as well as diagram techniques such as cause and effect diagrams or Strengths Weaknesses Opportunities and Threats (SWOT) are applied. The categorization and prioritization of risks will be carried out through the Analytic Hierarchy Process (AHP). Finally, a sensitivity analysis will allow for providing consistency to the obtained results. A real case in the Dominican Republic will also be presented as case study.
The impact of a near-Earth object (NEO) may release large amounts of energy and cause serious dam... more The impact of a near-Earth object (NEO) may release large amounts of energy and cause serious damage. Several NEO hazard studies conducted over the past few years provide forecasts, impact probabilities and assessment ratings, such as the Torino and Palermo scales. These high-risk NEO assessments involve several criteria, including impact energy, mass, and absolute magnitude. The main objective of this paper is to provide the first Multi-Criteria Decision Making (MCDM) approach to classify hazardous NEOs. Our approach applies a combination of two methods from a widely utilized decision making theory. Specifically, the Analytic Hierarchy Process (AHP) methodology is employed to determine the criteria weights, which influence the decision making, and the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) is used to obtain a ranking of alternatives (potentially hazardous NEOs). In addition, NEO datasets provided by the NASA Near-Earth Object Program are utilized. This approach allows the classification of NEOs by descending order of their TOPSIS ratio, a single quantity that contains all of the relevant information for each object. Asteroids, described as small rocky bodies with sizes consisting of a few metres to a few hundred kilometres in diameter, constitute a potential threat. While most of them might impact the Earth in the next million years with a probability close to 0.5% 1 , there is a chance of approximately 1% that an impact > 1000 MT (equivalent to 100 Tunguskas) might happen once each century 2. Hence, several studies have explored the implications of large asteroid impacts on early Earth ecosystems 3,4. It turns out that the determination of the statistical frequency of an asteroid impact is less relevant than stating whether an asteroid may impact the Earth 5. Even small objects (with diameters ranging from 50 to 100 m) may cause great damage. In fact, these types of small objects may lead to so-called Tunguska-class events whose impact energy is equivalent to 10 MT of TNT 6. Near-Earth objects (NEOs) are small asteroids that orbit close to the Earth's orbit. NEO research provides information concerning the evolution of the early solar system 7. Several measures to rate hazardous NEOs have been contributed in the scientific literature 8. Among them are the Torino scale 9 , which evaluates the a priori risk due to a potentially hazardous asteroid, and the Palermo scale 10 , which takes into account the energy at impact and the estimated probability of the event (that might happen in a time period spanning from present time to predicted impact) with respect to a record of events with a comparable or greater level 11. Several factors, including impact energy, impact velocity, estimated diameter, number of potential impacts, absolute magnitude, and impact probability, are also used to quantify the risk of NEO impacts 10. Furthermore, other non-physical factors such as Purgatorio Ratio (PR) have been used to manage the communication of impact threats; in this case, the PR is expressed by the ratio of time between the first and last observation to the time between the present and next possible impact date 12. Therefore, it is clear that an assessment of hazardous NEOs involves a wide list of varied nature criteria. The impact hazard assessment requires the development of ad hoc techniques beyond what is routinely conducted by automatic impact monitoring systems 13. In this paper, we contribute the first known Multi-Criteria Decision Making (MCDM) approach for hazardous NEO assessment. More specifically, we have applied the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) to classify hazardous NEOs. Next, we will motivate the application of MCDM techniques to hazardous NEO assessment. A MCDM problem consists of a set of alternatives to be evaluated with respect to a list of criteria. All that information is contained in a decision matrix. The main goal is to find the best option among all the alternatives once they have
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Papers by J. Sánchez-Lozano