A hybrid approach of VIKOR and bi-objective integer linear programming for electrification planning in a disaster relief camp

In this paper, we provide a model which optimizes the allocation of electricity generation systems, in terms of their number and location, in a disaster relief camp. The objectives that this model takes into account are minimization of the total cost of the project and prioritization of those generation systems that perform favourably. Energy and specifically electricity plays an important role in the provision of essential needs like lighting, water purification, heating, ventilation and medical care for displaced people. Disaster relief camps are commonly considered as off-grid projects, so individual generation and control systems are the main means of electrification. To support decision makers in electrification planning for temporary and semi-temporary camps, we propose a bi-objective integer linear programming model. The performance evaluation of technologies such as fuel generators, wind turbines and solar panels is conducted with an MCDM (VIKOR) approach. The model is applied on a hypothetical but realistic map site with data regarding commercially available equipment. The better performance of solar panels regarding the evaluation criteria have made them the dominant applied source of renewable electricity generation system and together with application of micro-grids in the model they have proven to reduce the cost of generation significantly. However, installing fuel generators have been found necessary for facilities which can cause a remarkable damage in case of electricity interruption. The model is promising in helping relief aid agencies to design an electrification project with minimum cost and maximum utility

Multicriteria analysis of renewable-based electrification projects in developing countries

The design of wind-photovoltaic stand-alone electrification projects that combine individual systems and microgrids is complex and requires from support tools. In this paper, a multicriteria procedure is presented in detail, which aims to assist project developers in such a design. More specifically, the procedure has been developed under a four-part structure, using support tools and expert consultations to enhance practicality into the rural context of developing countries. First, from a large amount of criteria, a reduced and easy to handle set is chosen, representing the main characteristics to be assessed in rural electrification projects. Second, two iterative processes, one based on the Analytical Hierarchy Process and one based on a typical 1–10 assessment, are tested to assign weights to the criteria, reflecting end-user preferences. Third, some indicators are proposed to evaluate the accomplishment of each solution regarding each criterion, in an objective manner. Fourth, considering the weights and evaluations, the solutions are ranked, using the compromise programming technique, thus selecting the best one/s. The whole procedure is illustrated by designing the electrification project of a real community in the Andean highlands. In short, this paper provides insights about the suitable decision-making process for the design of wind-PV electrification systems and, in addition, shows how different multicriteria techniques are applied to a very local context in rural, remote and very poor areas of developing countries.Peer ReviewedPostprint (author's final draft

Multi-Criteria Decision Making for Photovoltaic Alternatives: A Case Study in Hot Climate Country

Photovoltaic (PV) experiences significant growth and has installed in many locations worldwide over the past decades. However, selecting the best alternative of PV system remains a problem in developing countries which often involves both interest and multiple objectives and from stakeholders. This research aims to select ideal PV model in an isolated island in the eastern part of Indonesia. Multi-criteria decision making (MCDM) will provide an ideal solution that uses a systematic process of decision making. This research proposes an alternative concept of MCDM by taking into account best-worst method and VIKOR method. In general, the main purpose of the both methods are to obtain weights and rank alternatives with the advantages of less information required and produce a more consistent result compared to AHP method. The result shows the best alternative for PV installation, which offers the highest power and potentially developed not only for daily access to electricity but also to support economic activities such as tourism and aquaculture

Disaster relief operations: past, present and future

The aim of the preface is to introduce the scope of this special issue (SI). We explain our editorial approach and summarise our findings based on articles included in this SI. Finally, we outline future research questions which stemmed out of the discussions of this SI

Sustainable energy solutions for the Aegean Archipelago Islands: What is the public attitude?

In contributing towards the realisation of plans to transform the Aegean into a “green” archipelago, the internationally acclaimed TILOS research consortium seeks to transfer tacit knowledge of smart micro-grids beyond the island of Tilos. However, research on public acceptability of sustainable energy technologies suggests that local opposition might undermine such plans. In order to minimize the problems of technological transfers it is, thus, imperative to embark on an early-stage exploration of public attitudes towards proposed interventions. In this paper, we draw on survey data from across the Aegean to uncover the widespread acceptability of green energy solutions. Simultaneously, though, we uncover how broad acceptability does not always translate into actual acceptance of the TILOS energy model, especially with respect to solutions that affect the end-user. In turn, we argue that these findings should inform future interventions with the ultimate aim of securing public support to “green” the Aegean

Bringing innovation to market: business models for battery storage

Power systems around the world have undergone significant transitions towards a decentralization and decarbonization with higher requirements on supply security and flexibility. Technology advancement helps to improve energy efficiency and bring down cost, which in turn promote the growth of battery storage internationally. Business models of battery storage remain vague given its early stages of development but it is clear that there is no universal business model for batteries given the breadth of applications. In this study, we review the main components of existing business models and highlight the areas to be strengthened in a novel business model. Business models should be distinguished at different scales (utility-scale; behind-the-meter application; community-island mode operation) addressing different needs (to replace existing system or to add new capacity). A successful business model of a battery storage system needs to take into account electricity system transition, market and regulatory barriers, among others. Last but not least, it is important to consider innovations in other technologies for the design of a business model

The case for islands’ energy vulnerability: Electricity supply diversity in 44 global islands

Energy supply security is a multifaceted challenge for all countries and especially for small island nations that might have limited adaptive capacity. Previous studies showed that islands experience energy scarcity and isolation from energy markets due to their remote location making energy supply security a challenging issue. We estimate energy supply diversity and concentration for 44 islands in order to provide an island specific benchmark approach for energy supply security. We use established metrics Shannon-Wiener index (SWI), Herfindahl-Hirschman index (HHI) with Energy Information Administration (EIA) fuel mix data. To confront the issues of supply security and sustainability we test energy diversity against energy and emissions intensity. The global character of the research along with the wide range of islands covered allows useful comparisons between countries and for a means of benchmarking against the indices while creating certain defined country clusters. Overall it is found that average island energy intensity increased by 23.4% with a corresponding increase of 12.4% on their emissions intensity for the period 2000–2015. On the other hand, diversity has improved by 21.3% (SWI) and by 2% (HHI) since 2000. We argue that fossil-fuel lock-in for islands must break in order to UN Sustainable Development Goal 7 to be achieved particularly for vulnerable island nations

Humanitarian logistics optimization models: An investigation of decision-maker involvement and directions to promote implementation

Reports of successful implementation of humanitarian optimization models in the field are scarce. Incorporating real conditions and the perspective of decision-makers in the analysis is crucial to enhance the practical value and managerial implications. Although it is known that implementation can be hindered by the lack of practitioner input in the structure of the model, its priorities, and the practicality of solution times, the way these aspects have been introduced in humanitarian optimization models has not been investigated. This study looks at the way research has involved practitioners in different aspects of the design of optimization models to promote implementation. It investigates the aspects affecting the implementation of the models and opportunities to guide future optimization contributions. The article introduces a systematic literature review of 105 articles to answer the research questions. The results are contrasted with a multi-criteria decision analysis using responses from Mexican practitioners. The study found that only 10% of the articles involved practitioners for modelling decisions, which was confirmed by a major gap between the objectives used in the literature and the priorities of Mexican practitioners. In terms of swift decision-making, fewer than 22% of the articles surveyed introduced new solution methods to deliver results in a sensible time. The study also identified very limited inclusion of environmental concerns in the objective functions even though these are a priority in the global agenda. These findings are discussed to propose research directions and suggest best practices for future contributions to promote the implementation of humanitarian logistics models

OPTIMIZACIÓN EN DIMENSIONAMIENTO Y CONTROL ENERGÉTICO DE SISTEMAS HÍBRIDOS DE ENERGÍAS RENOVABLES EN ECUADOR

La creciente demanda de energía eléctrica referida como factor clave en el desarrollo de la sociedad actual, junto con una industria basada principalmente en hidrocarburos, impulsan el desarrollo de nuevas tecnologías renovables que podrían encaminar a un desarrollo sostenible. Por lo tanto, la presente Tesis tiene como objetivo analizar la factibilidad de sistemas híbridos compuestos por energías renovables, su optimización y control energético en el Ecuador. En base a ello, en este documento se han realizado varios estudios donde se analiza el impacto de sistemas híbridos renovables (HRES) compuesto por energía fotovoltaica (PV), turbinas hidrocinéticas (HKT), turbinas eólicas (WT), baterías y gasificadores de biomasa (GB). Las simulaciones de los HRES, en algunos casos se realiza utilizando herramientas computacionales como HOMER Pro y Matlab Simulink. Los resultados demuestran que, al utilizar sistemas renovables conformados por más de una fuente energética son más eficientes con respecto a sistemas con una sola fuente renovable. Esta Tesis también presenta una comparativa entre tres sistemas alternativos para impulsar a un tranvía ubicado en Cuenca - Ecuador. Cada sistema estudia la combinación efectiva de supercondensadores (SC), baterías de iones de litio (LIB) y celdas de combustible de membrana de intercambio de protones (PEMFC) a bordo. El primer sistema trata de la gestión energética de las fuentes renovables (PV/HKT/GB) en conjunto con SC y PEMFC simuladas en HOMER Pro, el segundo sistema utiliza baterías de ion litio como respaldo al sistema anterior mencionado (PV/HKT/GB/SC/PEMFC/LIB). Mientras que el tercer sistema no cuenta con fuentes renovables ya que utiliza energía de la red desde un único punto de carga para abastecer al tranvía, este sistema está formado por (SC/PEMFC/LIB/red eléctrica) haciendo que el tranvía sea completamente autónomo. El análisis energético y económico se basa en la capacidad de cada sistema para abastecer la carga y los recursos utilizados. Los resultados muestran que los nuevos sistemas de control propuestos son siempre capaces de suministrar la potencia que necesita el tranvía durante todo su recorrido. Otro bloque analizado en esta Tesis son los sistemas multienergéticos que, recientemente han sido protagonistas de un creciente interés en este campo. Este tipo de redes involucran diferentes vectores de energía y los trata en su conjunto. Los casos más típicos contemplan subsistemas eléctricos, de gas natural e hidrógeno. Se han realizado múltiples esfuerzos para modelar este tipo de redes para problemas de gestión energética. La sección final de esta Tesis tiene como objetivo desarrollar un modelo de microredes (MG) completo pero manejable y multienergético, que permita representar con precisión la interacción entre los subsistemas eléctricos, de gas natural e hidrógeno. Los resultados muestran que el modelo desarrollado es capaz de representar con precisión el comportamiento operativo de las microrredes multienergéticas, que pueden ser valiosas para múltiples herramientas de investigación y educación aplicadas en estaciones de servicio híbridas.The growing electrical demand considered a key factor in the development of today's society, together with an industry based mainly on hydrocarbons, are driving the development of new renewable technologies that could lead to sustainable development. Therefore, this thesis aims to analyze the feasibility of hybrid systems composed of renewable energies, their optimization and energy control in Ecuador. Based on, several studies have been done where the impact of off-grid renewable hybrid systems (HRES) composed of photovoltaic energy (PV), hydrokinetic turbines (HKT), wind turbines (WT), batteries and biomass gasifiers (GB). The simulations of HRES have been done using computational tools such as HOMER Pro and Matlab Simulink. The results have shown that, by using renewable systems made up of more than one energy source simultaneously, the system is more efficient and promising. This work also presents a comparison of three alternative systems to supply the traction power of a tramway in Cuenca - Ecuador. Each system studies the effective combination of supercapacitors (SC), lithium-ion batteries (LIB), and proton exchange membrane fuel cells (PEMFC) on board. The first system deals with the energy management of renewable sources (PV/HKT/GB) in conjunction with SC and PEMFC simulated in HOMER Pro, the second system uses lithium ion batteries as a backup to the above mentioned system (PV/HKT/GB/SC/PEMFC/LIB). While the third system does not consist of renewable sources, using energy from the grid in a single charging point to supply the tramway (SC/PEMFC/LIB/electrical grid) making the tramway completely autonomous. The energy and economic analyzes are based on the capacity of each system to supply the load and the resources used. The results show that the new proposed control systems are always capable of supplying the tramway on its round trip. Another block analyzed in this thesis is the multi-energy systems that, recently, there has been a growing interest in this field. This type of network involves different energy vectors and treats them as a whole. The most typical cases contemplate electrical, natural gas and hydrogen subsystems. Multiple efforts have been made to model this type of network for energy management problems. The final section of this thesis aims to develop a complete but manageable, but multi-energetic, microgrid model (MG) that allows to accurately represent the interaction between the electrical, natural gas and hydrogen subsystems. The results show that the developed model is capable of accurately representing the operational behavior of multi-energy microgrids, which can be valuable for multiple research and education tools applied to hybrid refueling stations.Tesis Univ. Jaén. Departamento De Ingeniería Eléctrica. Leída el 10 de febrero de 2021

Graph-based Algorithms for Smart Mobility Planning and Large-scale Network Discovery

Graph theory has become a hot topic in the past two decades as evidenced by the increasing number of citations in research. Its applications are found in many fields, e.g. database, clustering, routing, etc. In this thesis, two novel graph-based algorithms are presented. The first algorithm finds itself in the thriving carsharing service, while the second algorithm is about large graph discovery to unearth the unknown graph before any analyses can be performed. In the first scenario, the automatisation of the fleet planning process in carsharing is proposed. The proposed work enhances the accuracy of the planning to the next level by taking an advantage of the open data movement such as street networks, building footprints, and demographic data. By using the street network (based on graph), it solves the questionable aspect in many previous works, feasibility as they tended to use rasterisation to simplify the map, but that comes with the price of accuracy and feasibility. A benchmark suite for further research in this problem is also provided. Along with it, two optimisation models with different sets of objectives and contexts are proposed. Through a series of experiment, a novel hybrid metaheuristic algorithm is proposed. The algorithm is called NGAP, which is based on Reference Point based Non-dominated Sorting genetic Algorithm (NSGA-III) and Pareto Local Search (PLS) and a novel problem specific local search operator designed for the fleet placement problem in carsharing called Extensible Neighbourhood Search (ENS). The designed local search operator exploits the graph structure of the street network and utilises the local knowledge to improve the exploration capability. The results show that the proposed hybrid algorithm outperforms the original NSGA-III in convergence under the same execution time. The work in smart mobility is done on city scale graphs which are considered to be medium size. However, the scale of the graphs in other fields in the real-world can be much larger than that which is why the large graph discovery algorithm is proposed as the second algorithm. To elaborate on the definition of large, some examples are required. The internet graph has over 30 billion nodes. Another one is a human brain network contains around 1011 nodes. Apart of the size, there is another aspect in real-world graph and that is the unknown. With the dynamic nature of the real-world graphs, it is almost impossible to have a complete knowledge of the graph to perform an analysis that is why graph traversal is crucial as the preparation process. I propose a novel memoryless chaos-based graph traversal algorithm called Chaotic Traversal (CHAT). CHAT is the first graph traversal algorithm that utilises the chaotic attractor directly. An experiment with two well-known chaotic attractors, Lozi map and Rössler system is conducted. The proposed algorithm is compared against the memoryless state-of-the-art algorithm, Random Walk. The results demonstrate the superior performance in coverage rate over Random Walk on five tested topologies; ring, small world, random, grid and power-law. In summary, the contribution of this research is twofold. Firstly, it contributes to the research society by introducing new study problems and novel approaches to propel the advance of the current state-of-the-art. And Secondly, it demonstrates a strong case for the conversion of research to the industrial sector to solve a real-world problem