Evolution of the conceptualization of hydrogen through knowledge maps, energy return on investment (EROI) and national policy strategies

In order to address Climate Change and energy dependency challenges, hydrogen (H-2) is emerging as a promising energy carrier. Studies related to its production have conceptualized it as green (GH(2)), clean, renewable (RH2), ecological, and sustainable (SH2). The aim of this research is to deepen the understanding of the GH(2) concept and to state boundaries between different terms. To reach this objective, a bibliometric analysis of publications indexed in SCOPUS is launched. Also, in order to assess the potential of renewable energy sources (RES) for GH(2) production, a review of the meta-analysis literature on the Energy Return on Energy Invested (EROI) ratio as regards these RES is performed. Additionally, an analysis of main national strategies on GH(2) is launched. Results indicate that the GH(2) concept is gaining remarkable relevance, while the keyword maps show no significant differences between SH2, RH2 and GH(2). EROI reveals low average values for the different biomass energy production processes. For their part, GH(2) national strategies focus mainly on solar and wind technologies, albeit leaving the door open to biomass, where EROI could become an adequate metric to guide these strategies towards a low carbon energy path. Although the role of biomass may become fundamental in this energy transition process, given its low EROI values and considering that it is not a totally clean RES, it should be indexed as RH2, but not always as GH(2). Finally, a proposal that guides a more appropriate use of the term GH(2) is made.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Willmer Guevara received a grant to facilitate the stay at the UPV/EHU of trainee researchers from Latin American countries enrolled in doctoral studies at the UPV/EHU (2021), to develop this project

Effect of Symmetrically Switched Rectifier Topologies on the Frequency Regulation of Standalone Micro-Hydro Power Plants

Micro-hydro power plants (μHPPs) are a major energy source in grid-isolated zones because they do not require reservoirs and dams to be built. μHPPs operate in a standalone mode, but a continuously varying load generates voltage unbalances and frequency fluctuations which can cause long-term damage to plant components. One method of frequency regulation is the use of alternating current-alternating current (AC-AC) converters as an electronic load controller (ELC). The disadvantage of AC-AC converters is reactive power consumption with the associated decrease in both the power factor and the capacity of the alternator to deliver current. To avoid this disadvantage, we proposed two rectifier topologies combined with symmetrical switching. However, the performance of the frequency regulation loop with each topology remains unknown. Therefore, the objective of this work was to evaluate the performance of the frequency regulation loop when each topology, with a symmetrical switching form, was inserted. A MATLAB® model was implemented to simulate the frequency loop. The results from a μHPP case study in a small Cuban rural community called ‘Los Gallegos’ showed that the performance of the frequency regulation loop using the proposed topologies satisfied the standard frequency regulation and increased both the power factor and current delivery capabilities of the alternator.This contribution is a result of a cooperation between the APlied Electronic Research Team (APERT) at the University of the Basque Country (UPV/EHU), supported by the Department of Education of the Basque Government, within the fund for research groups of the Basque university system IT978-16, the Power Electronics Control in Energy and Motion Systems group (PECEM) at the University of Oriente, and the IRIS project for Cuban energy transformation. Integration of Renewable Intermittent Sources in the power system (IRIS, 2019-2022) is financed by Academy of Science in Finland, Grant/Award Number 320229. The authors of this article gratefully acknowledge these financers and project partners

World Environment Day: Understanding Environmental Programs Impact on Society Using Twitter Data Mining

Environmental sustainability awareness has encouraged the promotion of a number of environmental programs and initiatives and, accordingly, the use of social networks for the dissemination and support of these initiatives has grown significantly. Thus, the purpose of the work is to understand United Nations World Environment Day (WED) programs impact on the digital public debate using Twitter data mining. For that, an ad hoc methodology is designed to provide it to authorities and organizations that wish to analyze the impact of different initiatives or programs on society. All in all, the research carried out analyzes more than 400,000 tweets sent during the 2021 edition of the WED. The tweets have been processed using Big Data techniques and Social Network Analysis. The research reveals that the WED was a trending topic initiative that was discussed in positive terms, where collective sentiment was shown. The topics covered dealt with the event day and the different initiatives related to restoration of ecosystems. However, it is noted that: there is no coordinated action by the institutions, groups or individuals involved in the conversation and the initiative tends towards homophily; digital mobilization is mostly centered in the host country (Pakistan) and, above all, in the neighboring country (India) and, the conspicuous absence of the business sphere in the discussion.Open Access funding provided thanks to the CRUE‑CSIC agreement with Springer Nature

Heating demand as an energy performance indicator: A case study of buildings built under the passive house standard in Spain

[EN]This paper aims to identify more simplified and appropriate energy performance indicators (EPIs) for residential buildings during their operational stage. The Spanish Energy Performance Certification methodology is used to evaluate the energy performance rate (EPR) of a selected sample of Passive House (PH) buildings. Results of the study indicate: all the certified PH buildings analyzed are nearly zero-energy buildings (NZEBs) under the Spanish certification system; disaggregate indicators (particularly heating and cooling demand), appear to be suitable EPIs for comparing buildings among different certification schemes and labels; the new Technical Building Code (TBC) offers greater flexibility in terms of creating NZEBs than previous laws, having the advantage that it involves very different (albeit closely linked) economic sectors, and represents a step forward in accomplishing the NZEB goal, and a clear boost to the renewable energies and energy efficiency in the Spanish building sector. However, it only states aggregate EPIs as limiting values, which may alter competition between different energy carriers/solutions. On the other part, the requirement level of the new TBC in relation to energy demand still needs to be verified. Moreover, the use of aggregate EPIs does not necessarily pave the way towards the "passive building" concept.The authors acknowledge research funding from the Basque Gov-ernment IT 1259-19 Grant. We would like to thank the inestimable help of Daniel Sanchez Peinado, Technical assistant of the Spanish Passive House Platform (PEP) and Jesus Cuadrado, Professor of the Department of Mechanical Engineering of the UPV-EHU. We also thank the anony-mous reviewers for their comments, which have helped to improve the quality of this work

Organizational Culture Transformation Model: Towards a High Performance Organization

Purpose: The main objective of this research is to design an Organizational Culture Transformation Model (OCTM) prototype, in order to enable a High Performance Organization (HPO). Design/methodology/approach: There are three main processes involved in the methodology. Two of them, the definition of the main OCTM work elements as an initial hypothesis based on a work environment approach and the scientific visualization of the key Organizational Culture research hubs through the analysis of the main topics in research publications, flow in parallel. Subsequently, at a certain point, both of these merges in a third process, the OCTM prototype definition. This last process, will deliver the Organizational Culture Transformation Model prototype, which essentially constitutes the main objective of the study. Findings: As result of the methodology, an Organizational Culture Transformation Model prototype has been developed. Originality/value: The resulting model will serve as a reference framework for those companies that wish to conduct an in-depth re-structuring of their operations, focusing it on their human capital

Commercial maps of the main Latin American countries in the international olive oil market

Aim of study: World trade in olive oil is undergoing structural changes, with the emergence of new relevant actors, notably South American countries. The objective of this study was to analyze the performance of emerging Latin American countries in the world olive oil market during the period 2010–2019. Area of study: Major Latin American countries within an international context. Material and methods: The study was conducted through an analysis of trade networks, the application of the export growth decomposition method, the index of import dependence, and competitiveness matrices developed from the statistical evolution of import share and market share indicators. Main results: European countries continue to dominate international trade in olive oil, however, Chile and Argentina have managed to widen their role. Chile was the country with the highest growth rate in olive oil exports in terms of value and volume in the period analyzed, whereas Argentina was below the world average. Prices in general have been stagnant, although price variability between countries can be distinguished. This may be due to the re-export policy of some countries, the qualities, the format, and some intrinsic characteristics of the markets. Research highlights: Chile and Argentina figure prominently for their commercial capacity, with the former focusing mainly on the USA and Brazilian markets, and the latter on the Spanish

Strategic management of patents on electrochemical conversion fuel cells and batteries in Latin America as a mechanism for moving towards energy sustainability

Electrochemical conversion batteries (ECBs), especially fuel cells and lithium-ion batteries (LIBs), are the focus of attention of the scientific community due to their potential contribution to the decarbonization of the economy. In this context, the objective is to analyze patent publication flows on LIBs in Latin America (LATAM) by proposing a technology adoption matrix, a Patents friendly to sustainable technologies (PFST) indicator, and the use of technology s-curves. Data collection and analysis were carried out using the PatSeer knowledge base, Gephi, VantagePoint, and Loglet Lab software. The results show the leadership of Brazil, Mexico, and Argentina, with high dependence on the United States, Japan, and Germany. The PFST indicates that 79.3% of the published patents address climate change mitigation. In general, there is a low rate of publication of ECB patents in LATAM, marked by a technological lag in the evolution of key technologies. Patents on fuel cells are more published than those related to LIB. Under this scenario, it is unlikely that LATAM will achieve the necessary competitiveness to produce complex technologies in this field. In this regard, it follows that to reverse the position of traditional exporters of low value-added commodities, these countries should formulate strategies that allow the development of the innovation ecosystem, promoting open and applied innovation mechanisms, subsidized adoption, greater integration of universities and, at the same time, strengthening technological integration with countries that currently lead the transfer and others with great potential such as China and South Korea.This project has received Open Access funding provided by University of Basque Country. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

Patentometric: monitoring the scientific and technological trends of Additive Manufacturing in Medical Applications

Patents are a means of protecting inventions developed by firms, institutions or individuals, and they may be interpreted as indicators of invention. Patents indicators convey information on the processes of inventive activities. Therefore, patent statistics will assess science and technology (S&T) activities. Besides, additive manufacturing (AM) has become a revolutionary technology that is changing medical science. For this reason, the patent statistics will allow us to monitor what is the state of the inventive activity of AM in medical applications. The database used in order to retrieve patent information is Patseer and the data have been analyzed through the analytics package called Quick Stats. From the data obtained, it can be concluded that, additive manufacturing in medical applications is an emerging technology with huge market potential. Undoubtedly, the core of invention is located in United States, followed by Germany, United Kingdom and China somewhat behind. Firms are the main holders of legal rights, and the firm’s market value and the knowledge diffusion of technology are ensured by the technological diversity and the number of forward citations presented by patents

High-Voltage Stations for Electric Vehicle Fast-Charging: Trends, Standards, Charging Modes and Comparison of Unity Power-Factor Rectifiers

Emission of greenhouse gases and scarcity of fossil fuels have put the focus of the scientific community, industry and society on the electric vehicle (EV). In order to reduce CO2 emissions, cutting-edge policies and regulations are being imposed worldwide, where the use of EVs is being encouraged. In the best of scenarios reaching 245 million EVs by 2030 is expected. Extensive use of EV-s requires the installation of a wide grid of charging stations and it is very important to stablish the best charging power topology in terms of efficiency and impact in the grid. This paper presents a review of the most relevant issues in EV charging station power topologies. This review includes the impact of the battery technology, currently existing standards and proposals for power converters in the charging stations. In this review process, some disadvantages of current chargers have been identified, such as poor efficiency and power factor. To solve these limitations, five unidirectional three-phase rectifier topologies have been proposed for fast EV charging stations that enhance the current situation of chargers. Simulation results show that all the proposed topologies improve the power factor issue without penalizing efficiency. The topologies with the best overall performance are the Vienna 6-switch and the Vienna T-type rectifier. These two converters achieve high efficiency and power factor, and they allow a better distribution of losses among semiconductors, which significantly increase the life-cycle of the semiconductor devices and the reliability of the converter.This work was supported in part by the Government of the Basque Country through the Fund for Research Groups of the Basque University System under Grant IT978-16, in part by the Research Program ELKARTEK under Project ENSOL2-KK-2020/00077 and Project HARVESTGEN-KK-2020/00113, in part by the Ministerio de Ciencia e Innovacion of Spain under Project PID2020-115126RB-I00, and in part by the FEDER Funds. Documen

¿Es rentable invertir en nueva maquinaría para fabricar paneles solares?

Duración (en horas): De 21 a 30 horas. Destinatario: EstudianteEl proyecto tiene como fin llevar a cabo el proceso de la toma de decisión en lo que respecta a un cambio de maquinaria para producir paneles solares, todo ello basado en variables económicas que se han estudiado a través de la estadística. Para ello, los alumnos se agrupan formando equipos de trabajo de 3-4 personas y se empieza con el desarrollo del proceso para tomar una decisión y presentarsela a los cargos directivos de la empresa. En este proceso se compaginan ambas asignaturas. La asignatura de economía les permitirá estudiar el proceso de rentabilidad de los bienes materiales y la influencia de factores económicos ajenos a empresa, como es la demanda, en la obtención de beneficios. La asignatura de estadística, a su vez, les ayuda a identificar las variables que afectan a la rentabilidad de la empresa y a estudiar qué tipo de distribución siguen, con el fin de realizar una simulación del proceso que pueda justificar el proceso de la toma de decisión