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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
701

Kogenerační zdroj / Cogeneration Unit

Jančok, Lukáš January 2013 (has links)
V diplomové práci je krok po kroce vypracováno řešení zabezpečení energetického zdroje pro typické město v Sibiřské oblasti. Data, která tvoří zadání, byla získána od zákazníka pomocí dotazníku, protože pro nás oblast v čase vypracování nebyla dostupná. Na základě informací o aktuální energetické situaci, obyvatelstvu a dřevospracujícímu průmyslu je vybrána vhodná technologie pro zabezpečení tepla a elektrické energie. Druh zdroje byl vybrán dle dostupného paliva a následně byl proveden výpočet a design en- ergetického zdoje založeného na Rankine Clausiovém cyklu. Řešení obsahuje technický i ekonomický návrh. Technické řešení ukázalo, že nejdůležitější parametry jsou spolehlivost, bezpečnost a jednoduchost řešení. Design sítí, přídavných zařízení a plánování údržby není obsahem této práce. O dalších projektových krocích pojednává závěr.
702

Towards Prescriptive Analytics in Cyber-Physical Systems

Siksnys, Laurynas 14 May 2014 (has links)
More and more of our physical world today is being monitored and controlled by so-called cyber-physical systems (CPSs). These are compositions of networked autonomous cyber and physical agents such as sensors, actuators, computational elements, and humans in the loop. Today, CPSs are still relatively small-scale and very limited compared to CPSs to be witnessed in the future. Future CPSs are expected to be far more complex, large-scale, wide-spread, and mission-critical, and found in a variety of domains such as transportation, medicine, manufacturing, and energy, where they will bring many advantages such as the increased efficiency, sustainability, reliability, and security. To unleash their full potential, CPSs need to be equipped with, among other features, the support for automated planning and control, where computing agents collaboratively and continuously plan and control their actions in an intelligent and well-coordinated manner to secure and optimize a physical process, e.g., electricity flow in the power grid. In today’s CPSs, the control is typically automated, but the planning is solely performed by humans. Unfortunately, it is intractable and infeasible for humans to plan every action in a future CPS due to the complexity, scale, and volatility of a physical process. Due to these properties, the control and planning has to be continuous and automated in future CPSs. Humans may only analyse and tweak the system’s operation using the set of tools supporting prescriptive analytics that allows them (1) to make predictions, (2) to get the suggestions of the most prominent set of actions (decisions) to be taken, and (3) to analyse the implications as if such actions were taken. This thesis considers the planning and control in the context of a large-scale multi-agent CPS. Based on the smart-grid use-case, it presents a so-called PrescriptiveCPS – which is (the conceptual model of) a multi-agent, multi-role, and multi-level CPS automatically and continuously taking and realizing decisions in near real-time and providing (human) users prescriptive analytics tools to analyse and manage the performance of the underlying physical system (or process). Acknowledging the complexity of CPSs, this thesis provides contributions at the following three levels of scale: (1) the level of a (full) PrescriptiveCPS, (2) the level of a single PrescriptiveCPS agent, and (3) the level of a component of a CPS agent software system. At the CPS level, the contributions include the definition of PrescriptiveCPS, according to which it is the system of interacting physical and cyber (sub-)systems. Here, the cyber system consists of hierarchically organized inter-connected agents, collectively managing instances of so-called flexibility, decision, and prescription models, which are short-lived, focus on the future, and represent a capability, an (user’s) intention, and actions to change the behaviour (state) of a physical system, respectively. At the agent level, the contributions include the three-layer architecture of an agent software system, integrating the number of components specially designed or enhanced to support the functionality of PrescriptiveCPS. At the component level, the most of the thesis contribution is provided. The contributions include the description, design, and experimental evaluation of (1) a unified multi-dimensional schema for storing flexibility and prescription models (and related data), (2) techniques to incrementally aggregate flexibility model instances and disaggregate prescription model instances, (3) a database management system (DBMS) with built-in optimization problem solving capability allowing to formulate optimization problems using SQL-like queries and to solve them “inside a database”, (4) a real-time data management architecture for processing instances of flexibility and prescription models under (soft or hard) timing constraints, and (5) a graphical user interface (GUI) to visually analyse the flexibility and prescription model instances. Additionally, the thesis discusses and exemplifies (but provides no evaluations of) (1) domain-specific and in-DBMS generic forecasting techniques allowing to forecast instances of flexibility models based on historical data, and (2) powerful ways to analyse past, current, and future based on so-called hypothetical what-if scenarios and flexibility and prescription model instances stored in a database. Most of the contributions at this level are based on the smart-grid use-case. In summary, the thesis provides (1) the model of a CPS with planning capabilities, (2) the design and experimental evaluation of prescriptive analytics techniques allowing to effectively forecast, aggregate, disaggregate, visualize, and analyse complex models of the physical world, and (3) the use-case from the energy domain, showing how the introduced concepts are applicable in the real world. We believe that all this contribution makes a significant step towards developing planning-capable CPSs in the future. / Mehr und mehr wird heute unsere physische Welt überwacht und durch sogenannte Cyber-Physical-Systems (CPS) geregelt. Dies sind Kombinationen von vernetzten autonomen cyber und physischen Agenten wie Sensoren, Aktoren, Rechenelementen und Menschen. Heute sind CPS noch relativ klein und im Vergleich zu CPS der Zukunft sehr begrenzt. Zukünftige CPS werden voraussichtlich weit komplexer, größer, weit verbreiteter und unternehmenskritischer sein sowie in einer Vielzahl von Bereichen wie Transport, Medizin, Fertigung und Energie – in denen sie viele Vorteile wie erhöhte Effizienz, Nachhaltigkeit, Zuverlässigkeit und Sicherheit bringen – anzutreffen sein. Um ihr volles Potenzial entfalten zu können, müssen CPS unter anderem mit der Unterstützung automatisierter Planungs- und Steuerungsfunktionalität ausgestattet sein, so dass Agents ihre Aktionen gemeinsam und kontinuierlich auf intelligente und gut koordinierte Weise planen und kontrollieren können, um einen physischen Prozess wie den Stromfluss im Stromnetz sicherzustellen und zu optimieren. Zwar sind in den heutigen CPS Steuerung und Kontrolle typischerweise automatisiert, aber die Planung wird weiterhin allein von Menschen durchgeführt. Leider ist diese Aufgabe nur schwer zu bewältigen, und es ist für den Menschen schlicht unmöglich, jede Aktion in einem zukünftigen CPS auf Basis der Komplexität, des Umfangs und der Volatilität eines physikalischen Prozesses zu planen. Aufgrund dieser Eigenschaften müssen Steuerung und Planung in CPS der Zukunft kontinuierlich und automatisiert ablaufen. Der Mensch soll sich dabei ganz auf die Analyse und Einflussnahme auf das System mit Hilfe einer Reihe von Werkzeugen konzentrieren können. Derartige Werkzeuge erlauben (1) Vorhersagen, (2) Vorschläge der wichtigsten auszuführenden Aktionen (Entscheidungen) und (3) die Analyse und potentiellen Auswirkungen der zu fällenden Entscheidungen. Diese Arbeit beschäftigt sich mit der Planung und Kontrolle im Rahmen großer Multi-Agent-CPS. Basierend auf dem Smart-Grid als Anwendungsfall wird ein sogenanntes PrescriptiveCPS vorgestellt, welches einem Multi-Agent-, Multi-Role- und Multi-Level-CPS bzw. dessen konzeptionellem Modell entspricht. Diese PrescriptiveCPS treffen und realisieren automatisch und kontinuierlich Entscheidungen in naher Echtzeit und stellen Benutzern (Menschen) Prescriptive-Analytics-Werkzeuge und Verwaltung der Leistung der zugrundeliegenden physischen Systeme bzw. Prozesse zur Verfügung. In Anbetracht der Komplexität von CPS leistet diese Arbeit Beiträge auf folgenden Ebenen: (1) Gesamtsystem eines PrescriptiveCPS, (2) PrescriptiveCPS-Agenten und (3) Komponenten eines CPS-Agent-Software-Systems. Auf CPS-Ebene umfassen die Beiträge die Definition von PrescriptiveCPS als ein System von wechselwirkenden physischen und cyber (Sub-)Systemen. Das Cyber-System besteht hierbei aus hierarchisch organisierten verbundenen Agenten, die zusammen Instanzen sogenannter Flexibility-, Decision- und Prescription-Models verwalten, welche von kurzer Dauer sind, sich auf die Zukunft konzentrieren und Fähigkeiten, Absichten (des Benutzers) und Aktionen darstellen, die das Verhalten des physischen Systems verändern. Auf Agenten-Ebene umfassen die Beiträge die Drei-Ebenen-Architektur eines Agentensoftwaresystems sowie die Integration von Komponenten, die insbesondere zur besseren Unterstützung der Funktionalität von PrescriptiveCPS entwickelt wurden. Der Schwerpunkt dieser Arbeit bilden die Beiträge auf der Komponenten-Ebene, diese umfassen Beschreibung, Design und experimentelle Evaluation (1) eines einheitlichen multidimensionalen Schemas für die Speicherung von Flexibility- and Prescription-Models (und verwandten Daten), (2) der Techniken zur inkrementellen Aggregation von Instanzen eines Flexibilitätsmodells und Disaggregation von Prescription-Models, (3) eines Datenbankmanagementsystem (DBMS) mit integrierter Optimierungskomponente, die es erlaubt, Optimierungsprobleme mit Hilfe von SQL-ähnlichen Anfragen zu formulieren und sie „in einer Datenbank zu lösen“, (4) einer Echtzeit-Datenmanagementarchitektur zur Verarbeitung von Instanzen der Flexibility- and Prescription-Models unter (weichen oder harten) Zeitvorgaben und (5) einer grafische Benutzeroberfläche (GUI) zur Visualisierung und Analyse von Instanzen der Flexibility- and Prescription-Models. Darüber hinaus diskutiert und veranschaulicht diese Arbeit beispielhaft ohne detaillierte Evaluation (1) anwendungsspezifische und im DBMS integrierte Vorhersageverfahren, die die Vorhersage von Instanzen der Flexibility- and Prescription-Models auf Basis historischer Daten ermöglichen, und (2) leistungsfähige Möglichkeiten zur Analyse von Vergangenheit, Gegenwart und Zukunft auf Basis sogenannter hypothetischer „What-if“-Szenarien und der in der Datenbank hinterlegten Instanzen der Flexibility- and Prescription-Models. Die meisten der Beiträge auf dieser Ebene basieren auf dem Smart-Grid-Anwendungsfall. Zusammenfassend befasst sich diese Arbeit mit (1) dem Modell eines CPS mit Planungsfunktionen, (2) dem Design und der experimentellen Evaluierung von Prescriptive-Analytics-Techniken, die eine effektive Vorhersage, Aggregation, Disaggregation, Visualisierung und Analyse komplexer Modelle der physischen Welt ermöglichen und (3) dem Anwendungsfall der Energiedomäne, der zeigt, wie die vorgestellten Konzepte in der Praxis Anwendung finden. Wir glauben, dass diese Beiträge einen wesentlichen Schritt in der zukünftigen Entwicklung planender CPS darstellen. / Mere og mere af vores fysiske verden bliver overvåget og kontrolleret af såkaldte cyber-fysiske systemer (CPSer). Disse er sammensætninger af netværksbaserede autonome IT (cyber) og fysiske (physical) agenter, såsom sensorer, aktuatorer, beregningsenheder, og mennesker. I dag er CPSer stadig forholdsvis små og meget begrænsede i forhold til de CPSer vi kan forvente i fremtiden. Fremtidige CPSer forventes at være langt mere komplekse, storstilede, udbredte, og missionskritiske, og vil kunne findes i en række områder såsom transport, medicin, produktion og energi, hvor de vil give mange fordele, såsom øget effektivitet, bæredygtighed, pålidelighed og sikkerhed. For at frigøre CPSernes fulde potentiale, skal de bl.a. udstyres med støtte til automatiseret planlægning og kontrol, hvor beregningsagenter i samspil og løbende planlægger og styrer deres handlinger på en intelligent og velkoordineret måde for at sikre og optimere en fysisk proces, såsom elforsyningen i elnettet. I nuværende CPSer er styringen typisk automatiseret, mens planlægningen udelukkende er foretaget af mennesker. Det er umuligt for mennesker at planlægge hver handling i et fremtidigt CPS på grund af kompleksiteten, skalaen, og omskifteligheden af en fysisk proces. På grund af disse egenskaber, skal kontrol og planlægning være kontinuerlig og automatiseret i fremtidens CPSer. Mennesker kan kun analysere og justere systemets drift ved hjælp af det sæt af værktøjer, der understøtter præskriptive analyser (prescriptive analytics), der giver dem mulighed for (1) at lave forudsigelser, (2) at få forslagene fra de mest fremtrædende sæt handlinger (beslutninger), der skal tages, og (3) at analysere konsekvenserne, hvis sådanne handlinger blev udført. Denne afhandling omhandler planlægning og kontrol i forbindelse med store multi-agent CPSer. Baseret på en smart-grid use case, præsenterer afhandlingen det såkaldte PrescriptiveCPS hvilket er (den konceptuelle model af) et multi-agent, multi-rolle, og multi-level CPS, der automatisk og kontinuerligt tager beslutninger i nær-realtid og leverer (menneskelige) brugere præskriptiveanalyseværktøjer til at analysere og håndtere det underliggende fysiske system (eller proces). I erkendelse af kompleksiteten af CPSer, giver denne afhandling bidrag til følgende tre niveauer: (1) niveauet for et (fuldt) PrescriptiveCPS, (2) niveauet for en enkelt PrescriptiveCPS agent, og (3) niveauet for en komponent af et CPS agent software system. På CPS-niveau, omfatter bidragene definitionen af PrescriptiveCPS, i henhold til hvilken det er det system med interagerende fysiske- og IT- (under-) systemer. Her består IT-systemet af hierarkisk organiserede forbundne agenter der sammen styrer instanser af såkaldte fleksibilitet (flexibility), beslutning (decision) og præskriptive (prescription) modeller, som henholdsvis er kortvarige, fokuserer på fremtiden, og repræsenterer en kapacitet, en (brugers) intention, og måder til at ændre adfærd (tilstand) af et fysisk system. På agentniveau omfatter bidragene en tre-lags arkitektur af et agent software system, der integrerer antallet af komponenter, der er specielt konstrueret eller udbygges til at understøtte funktionaliteten af PrescriptiveCPS. Komponentniveauet er hvor afhandlingen har sit hovedbidrag. Bidragene omfatter beskrivelse, design og eksperimentel evaluering af (1) et samlet multi- dimensionelt skema til at opbevare fleksibilitet og præskriptive modeller (og data), (2) teknikker til trinvis aggregering af fleksibilitet modelinstanser og disaggregering af præskriptive modelinstanser (3) et database management system (DBMS) med indbygget optimeringsproblemløsning (optimization problem solving) der gør det muligt at formulere optimeringsproblemer ved hjælp af SQL-lignende forespørgsler og at løse dem "inde i en database", (4) en realtids data management arkitektur til at behandle instanser af fleksibilitet og præskriptive modeller under (bløde eller hårde) tidsbegrænsninger, og (5) en grafisk brugergrænseflade (GUI) til visuelt at analysere fleksibilitet og præskriptive modelinstanser. Derudover diskuterer og eksemplificerer afhandlingen (men giver ingen evalueringer af) (1) domæne-specifikke og in-DBMS generiske prognosemetoder der gør det muligt at forudsige instanser af fleksibilitet modeller baseret på historiske data, og (2) kraftfulde måder at analysere tidligere-, nutids- og fremtidsbaserede såkaldte hypotetiske hvad-hvis scenarier og fleksibilitet og præskriptive modelinstanser gemt i en database. De fleste af bidragene på dette niveau er baseret på et smart-grid brugsscenarie. Sammenfattende giver afhandlingen (1) modellen for et CPS med planlægningsmulighed, (2) design og eksperimentel evaluering af præskriptive analyse teknikker der gør det muligt effektivt at forudsige, aggregere, disaggregere, visualisere og analysere komplekse modeller af den fysiske verden, og (3) brugsscenariet fra energiområdet, der viser, hvordan de indførte begreber kan anvendes i den virkelige verden. Vi mener, at dette bidrag udgør et betydeligt skridt i retning af at udvikle CPSer til planlægningsbrug i fremtiden.
703

Are solar home systems a more financially viable method of electrifying Ghana households?

Radebe, Thandwefika 24 February 2021 (has links)
Africa still has the lowest electrification rates in the world with over 600 million people estimated to be living without access to electricity. What makes the challenge even greater for Africa is that the continent is so sparsely populated that building grid infrastructure is not viable in many cases. However, “pay-as-you-go” solar home systems have provided the continent with the opportunity to correct its electrification deficit. These innovations are not new and many of the costs of operating these systems have reached grid parity when one considers the Levelized Cost of Energy Model. However, these projects still fail to meet institutional investors' bankability criteria. The aim of this study is to try and understand whether solar home systems provide the investor with an opportunity to make a larger risk-adjusted return versus existing grid-based power station projects being considered on the continent. This study uses Ghana's recently built Kpone power station as a case study to complete this analysis. The study also seeks to assess what viability criteria is employed by a broad base of investors if they were to consider funding off-grid power. The study makes use of the Net Present Value model to compare the returns for Kpone and Zola Electric's Infinity solar home system. The study also conducts inductive qualitative analysis to try and ascertain what criteria is assessed for project viability and then builds a conceptual framework for assessing future projects. The study found that Kpone provided a better risk-adjusted return to that of Zola Electric's solar home system, largely because of Kpone's project finance structure reducing the risk of the investment. Our findings also show that investment ticket size, company track record and management track record are among the most highly considered criteria for investments into off-grid companies.
704

Smart Grids and Turkey: An Overview of the Current Power System and Smart Grid Development

Keskin, Müge January 2021 (has links)
Successful integration of the smart grids is crucial for ensuring the efficiency, resiliency, and sustainability of future power systems. With a 46.53% increase in total primary energy supply between 2008 and 2018 (IEA, 2020a), Turkey has the fastest-growing energy market within OECD countries (Erdin and Ozkaya, 2019).Though, Turkey’s current electrical grid faces many challenges; such as high loss rates from the transmission and distribution lines (Damar, 2016; Düzgün, 2018; IBRD/The World Bank, 2016; TEİAŞ, 2019), frequent power outages (Guner and Ozdemir, 2011; Öztürk, 2017; Yanılmaz, 2016) and several incidents of large-scale blackouts (OECD/IEA, 2016; Project Group Turkey, 2015). Smart grid technologies can address Turkey’s power system’s challenges with a holistic approach, as the smart grid does not have a strict definition yet but has distinctive characteristics. This paper provides an overview of Turkey’s current electric power system’s challenges while analyzing Turkey’s progress up to the present day towards the smart grid transition. Also, in order to summarize fundamental smart grid technologies globally, a smart grid framework was designed. Founded upon the framework; Turkey’s previous actions for its power system development were assessed from the smart grid perspective, and further steps were proposed to accomplish a successful smart grid transition. Country-specific remarks regarding the electrical grid were highlighted, such as the risk of terrorism, high seismic activity in the region, and emerging nuclear power in the country. As a result, it is concluded that Turkey has initiated the process towards the smart grid transition not only to achieve a “smart grid ideal” but mainly to meet its growing energy demands. Furthermore, it is also concluded that if the smart grid technologies’ scope could be extended throughout the country, Turkey would overcome the challenges with its power system in short to medium-term.
705

Performance Indicators for Smart Grids : An analysis of indicators that measure and evaluate smart grids

Busuladzic, Ishak, Tjäder, Marcus January 2020 (has links)
Sweden has developed ambitious goals regarding energy and climate politics. One major goal is to change the entire electricity production from fossil fuels to sustainable energy sources, this will contribute to Sweden being one of the first countries in the world with non-fossil fuel in the electricity sector. To manage this, major changes need to be implemented and difficulties on the existing grid will occur with the expansion of digitalization, electrification and urbanization. By using smart grids, it is possible to deal with these problems and change the existing electricity grid to use more distributed power generation, contributing to flexibility, stability and controllability. The goal with smart grids is to have a sustainable electricity grid with low losses, security of supply, environmental-friendly generation and also have choices and affordable electricity for customers. The purpose of this project is to identify and evaluate several indicators for a smart grid, how they relate and are affected when different scenarios with different technologies are implemented in a test system. Smart grid indicators are quantified metrics that measure the smartness of an electrical grid. There are five scenarios where all are based on possible changes in the society and electricity consumption, these scenarios are; Scenario A – Solar power integration, Scenario B – Energy storage integration, Scenario C – Electric vehicles integration, Scenario D – Demand response and Scenario E – Solar power, Energy storage, Electric vehicles and Demand response integration. A model is implemented in MATLAB and with Monte Carlo simulations expected values, standard deviation and confidence interval were gained. Four selected indicators (Efficiency, capacity factor, load factor and relative utilization) was then analyzed. The results show that progress on indicators related to all smart grid characteristics is needed for the successful development of a smart grid. In scenario C, all four selected indicators improved. This shows that these indicators could be useful for promoting the integration of electric vehicles in an electricity grid. In Scenario A, solar power integration contributed to all indicators deteriorate, this means that, technical solutions that can stabilize the grid are necessary to implement when integrating photovoltaic systems. The load factor is a good indicator for evaluating smart grids. This indicator can incentivize for an even load and minimize the peak loads which contributes to a flexible and efficient grid. With the capacity factor, the utilization and free capacity can be measured in the grid, but it can counteract renewable energy integration if the indicator is used in regulation.
706

A Mapping of Scandinavian Smart Grid Development in the Distribution System from an ICT perspective

Christensson, Anja, Gerson, Nadine, Wallin, Edit January 2013 (has links)
No description available.
707

Solarizing Indian agriculture by deploying solar irrigation pumps

Dekker, Tobias Dylan January 2015 (has links)
Solar Irrigation Pumps (SIPs) are used to pump (ground and surface) water to irrigate farm lands. In a country with a historical mismatch of energy supply and demand, and almost 120 million families dependent on earnings from agriculture (Prachi Salve, 2014), SIPs offer great prospects. Unlike electric and diesel pumps – dominating the market till today – SIPs have almost zero marginal costs. This leads to extra crop production at negligible costs and also generation of electricity when not being used for pumping. Due to almost zero emissions, it simultaneously addresses the issue of climate change hence bringing prosperity to the population at all levels.SIPs are a new phenomenon in India and due to the comparatively1 high capital costs, SIPs require subsidies to make them affordable for a farmer. Support in the form of subsidies has been given to around 15,000 farms in the whole country. By introducing solar pumps on a subsidy scheme in 2009-2010, Rajasthan has become the pioneer state of India. Since then numerous solar pumps have been deployed and farmers have gained experience with their usage. These farmers appear to be happy with the functioning of the pumps; 95% of the farmers, who gained enough knowledge to answer the question, say that the pump works better than their diesel or electric pump. A surprising finding is that the project cost per pump is getting higher while the pumps are getting cheaper. This means that the government is using more money to run the project. To find the reasons for the rising project costs and to find a way to decrease them, further research is needed. If the project cost could be decreased more pumps could be supplied with the same amount of subsidy.It was also found that the SIPs were not successful in replacing the electric and diesel pumps. The diesel and electric pumps had more horse power (hp) so were able to pump more water resulting in irrigation of more land in the same amount of time. Farmers expressed they could fully switch to SIPs when more powerful pumps were supplied.Because the present SIPs are off grid systems, it is not possible to sell the excess electricity that is not needed for pumping water. Because there are no marginal costs, there is no incentive for switching off the machines either. The consequence is excessive pumping of water leading to groundwater depletion. An important improvement would be to connect these pumps to the electricity grid. The possibility to earn some money with delivering energy would probably be a good reason to stop needless pumping.The subsidy program that was in place in Rajasthan had an 86% capital subsidy (the farmer had to pay only 14% of the price of SIP). With the available money only 10,000 pumps per year could be supplied (Dr. Dinesh Kumar Goyal, 2013). When the subsidy per pump is decreased more pumps could be deployed and it was shown that even with a lower subsidy getting a SIP will still be attractive.One of the points of improvement for a quick roll out of SIPs might be found in the way these pumps are financed. Pumps have a high capital cost and are currently financed by 70-90% capital subsidies of the government. The amount of total subsidy is limited and so with a high percentage of subsidy a small amount of pumps are deployed by this subsidy. These subsidies could be dramatically reduced when a loan/lease product would be put in place. Without a bank loan farmers are unable to pay the major part of the capital cost of the pump. Offering a bank loan is a win-win situation for the farmers and the people of India, represented by the government. With these pumps farmers are able to sell electricity to the grid and earn extra income or they can sell water to other farmers for a price below the price of current diesel pumping. With this income they could pay off the loan in 7 years and earn a reasonable income. The people of India will not only benefit by having to pay less for subsidies, they will also benefit from less greenhouse gas emissions as solar has almost zero emissions compared to mainly coal based electricity pumps and diesel pumps.SIPs supplying electricity can have a big effect on grid stability. Hence, in chapter 6 the question of grid stability was raised. Under what conditions can the Indian grid deal with a large amount of electricity injected from SIPs. India currently has 70% of the electricity produced from coal power plants while 3% comes from Nuclear power plants (Trading Economics, 2011a). These sources have a response time of several hours which is not quick enough to respond to fluctuations in the demand of energy by for example households, or a change in production by other sources, for example solar. The present sources should be partly replaced by quick response sources like the renewable sources and gas turbines. Currently 6% of the installed capacity is a gas power plant (Central Electricity Authority, 2015) but this percentage should be increased. Also other solutions should be implemented, such as developing storage of energy and more interconnections between grids of states and other countries.Since the idea is that SIPs would not use electricity from the grid anymore unlike electric pumps, 25% of electricity currently used from the grid by agriculture will be less. The current electric pumps only get electricity for certain hours a day and are used to balance the grid, only at times of low electricity use of other users, farmers will get electricity. When the electric pumps are replaced by SIPs that do not use electricity from the grid the balancing function that the electric pumps currently fulfil will no longer be present. Having no experience with SIPs connected to the grid so far, it will be difficult for the state load dispatch centres, which manage the grid, to schedule the expected load. Hence, pilots should be set up to find out how these pumps are used throughout the day so that in the future these loads can be predicted. In Gujarat the solar installed capacity could easily be a fivefold without having to invest in extra capacity of quick responsive sources, since enough installed capacity of gas turbines is already in place but currently not used. Extra investment would be needed in the grid in order to be able to transmit so much electricity over the grid from the (distributed) solar plants.Solar irrigation pumps, when implemented correctly, can not only lead to much cheaper irrigation for farmers but also less groundwater depletion and a source of extra income. Solar pumps can lead the way to more prosperity for the Indian people, but new guidelines and plans have to be made by the government to realise this potential. Without policy changes as described in this thesis SIPs benefit a small number of lucky farmers at the expense of the larger whole (wasting public money and groundwater).
708

Dimensionering & simulering av ett PV-system för en eldriven båt / Sizing & simulation of a PV-system for an electric boat

Hjalmarsson, Tobias January 2021 (has links)
Examensarbetet som presenteras i denna rapport är ett delprojekt utfört i samarbete med Glava Energy Center och redovisar framtagningen av ett PV-system för den eldrivna båten Bowter. I rapporten utfördes en energianalys där solinstrålning i olika plan studerades och analyserades. Möjligheter att utöka antalet solceller baserat på båtens design undersöktes, där båtens horisontella badbrygga samt vertikala långsidor bedömdes vara de ytor som var lämpliga för placering. Förslag på konfigurationer av PV-systemet dimensionerades och den förväntade mängden genererad energi och laddning beräknades. Systemet som togs fram skulle enligt beräkningar i genomsnitt generera mellan 1,06–2,22kWh energi per dag och kosta omkring tio tusen kronor. Energianalysen visade att solceller placerade i 30–40° lutning i genomsnitt skulle kunna generera mellan 20–43 procent mer energi och laddning än den valda vertikala placeringen. Med båtens nuvarande design utan några möjligheter för placering av solceller i lutande plan går därmed denna potentiella mängd energi förlorad. Praktiska mätningar av energi via reflektioner från vattenytan visar heller inga övertygande tecken på att rädda upp för denna mängd förlorad energi. Simuleringar av det framtagna systemet genomfördes och jämfördes med det beräknade genomsnittet, vilket visade att man skulle kunna förvänta sig cirka 25 procent mer energi under klara förhållanden och 76 procent mindre energi under svåra väderförhållanden med långvariga och heltäckande moln. Av resultaten drogs slutsatsen att det mest praktiska alternativet för maximal systemeffekt är att möjliggöra placering av fler solceller i horisontellt plan via t.ex. en takdel och på den vägen erhålla ett mer pålitligt och förutsägbart resultat som både skulle vara mer effektivt samt ekonomiskt fördelaktigt i jämförelse med det framtagna systemet. / The thesis work presented in this report is a sub-project carried out in collaboration with Glava Energy Center and reports on the development of a PV system for the electric boat Bowter. In the report, an energy analysis was performed where solar irradiance in different planes was studied and analyzed. Opportunities to increase the number of solar cells based on the boat's design were investigated, where the boat's horizontal swim platform and vertical sides were determined to be the areas that were suitable for placement. Proposals for configurations of the PV system were sized and the expected amount of generated energy and charge capacity were calculated. According to calculations the proposed system would on average generate between 1.06–2.22kWh of energy per day and cost around SEK 10,000. The energy analysis showed that solar cells placed at an angle of 30–40° could on average generate between 20–43 percent more energy and charge than the chosen vertical placement. With the boat's current design without any possibilities for placing solar cells in an inclined plane, this potential amount of energy is lost. Practical measurements of energy via reflections from the water surface show no convincing signs of compensating for this amount of lost energy. Simulations of the proposed system were carried out and compared with the calculated average, which showed that one could count on about 25 percent more energy in clear conditions and 76 percent less energy in harsh weather conditions with long-lasting and overcast clouds. From the results, it was concluded that the most practical alternative for maximum system power is to enable the placement of additional solar cells in a horizontal plane via e.g. a roof section and in that way obtain a more reliable and predictable result that would be both more efficient and economically advantageous in comparison with the proposed system.
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Ledare utan plan : Uppgift- och relationsorienterat ledarskap inomrestaurangbranschen under coronapandemin. / Leaders without a plan : Task- and relations oriented leadership inresturants during the corona pandemic.

Pavlovic, Dorian, Nyberg Steinbrenner, John January 2021 (has links)
Studien handlar om att skapa förståelse kring huruvida restaurangchefer är i högre grad uppgifts- eller relationsorienterade i sitt ledarskap samt hur de hanterat corona pandemin. Studien har tagit utgångspunkt i insamling av empirisk data, för att vidare analysera materialet med hjälp av den teoretiska referensramen. Under den teoretiska referensramen har data samlats in kring de berörda ledarstilarna och hur de skiljer sig från varandra, samt hur en kris och krishantering kan se ut. Studiens empiriska avsnitt utgår ifrån en kvalitativ metod insamling där sju restaurangchefer intervjuades. Respondenterna och dess restauranger är belägna i Göteborg. Uppsatsens empiriska resultat stödjer teoretiska referensramen som implementeras i analysavsnittet.Författarna presenterar slutligen i slutsatsen att restaurangcheferna använder en kombination av uppgifts- och relationsorienterat ledarskap. Författarna kan dessutom fastslå att ingen chef utesluter den ena ledarskapsstilen. Studien visar tydliga samband där restaurangcheferna är antingen mer relations- eller uppgiftsorienterade i sitt ledarskap. I analysavsnittet visar det sig att restaurangcheferna hanterar krisen på olika sätt. De relationsorienterade restaurangcheferna var innovativa och arbetade med att skapa ytterligare intäkter, medans den uppgiftsorienterade ledaren effektiviserade organisationen och kapade kostnader. Ledarna har dock varit tydliga att ingen krisstrategi formats i förväg. Samtliga ledare har agerat reaktivt under den rådande pandemin då ingen liknande händelse inträffat dessförinnan. / The study is about creating an understanding of whether restaurant managers are more task- or relationship-oriented in their leadership and how they have handled the corona pandemic. The study is based on two parts, one of which is the collection of empirical data, the other from the theoretical frame of reference. During the theoretical frame of reference, data has been collected on the relevant leadership styles and how they differ from each other, as well as what a crisis and crisis management can look like. The empirical section of the study is based on a qualitative collection method where seven restaurant managers were interviewed. The respondents and their restaurants are located in Gothenburg. The empirical evidence of the thesis is supported in the theoretical frame of reference that is implemented in the analysis section.The authors presents in the conclusion that restaurant managers use a combination of task and relationship-oriented leadership. The authors can also state that no manager excludes a leadership style. The study shows clear connections where restaurant managers are either more relational or task-oriented in their leadership. In the analysis section, it turns out that the restaurant managers handle the crisis in different ways. The relationship-oriented restaurant managers were innovative and worked to create additional revenue, while the task-oriented leader streamlined the organization and reduced costs. However, the leaders have been clear that no crisis strategy has been formulated in advance. All leaders have acted reactively during the current pandemic because no similar event has occurred before.
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Impact of energy storage technologies in a distribution grid : An analysis of Key Performance Indicators relating to a local grid’s performance characteristics

Daun, Kevin January 2021 (has links)
The energy system is undergoing a transformation on a never before witnessed scale. The changes are driven by global market forces and technological advancements, improving on a seemingly exponential scale. This in turn has led to the price of both renewables and the accompanying technology decrease over time, making the transition into renewables more economically viable. The drawback of variable renewable energy is that it is variable and dependent on the surrounding environment. Therefore, storing the energy during hours of production, to be used at a later stage when energy demand is higher is becoming ever more important and an attractive option. The purpose of this degree project is to, from a set of performance indicators, evaluate three different energy storage technologies and their respective impact on a distribution grid. The examined storage technologies are: Batteries, Capacitators and a H2 Fuel cell. A literature study was performed in order to find out how grid performance is evaluated, and how the different storage technologies operate. The obtained literature comes from scientific reports, and papers, found by utilizing Mälardalens University library-database. A model representing a Swedish grid with a connection point to the distribution side was created. The model is taken from previous credited work, and customized to fit the operational parameters of a Swedish grid. It was decided that the key indicators for evaluating the state of a grid was to look at the: voltage- and frequency variations, load factor, capacity factor and the overall system efficiency. The simulation is a discrete time simulation that utilizes parameters indicative of one full day of data. The results showed that, from a technological standpoint, the supercapacitor performed better in more categories than the Li-ion battery and H2 fuel cell. However, the Li-ion battery reduced the peaks of the frequency measurements which is a key metric when deciding on grid health. Also, there is the added benefit of the battery and fuel cell of having a longer operational time before the state of charge is depleted. This increases the flexibility of the technology and could therefore be more beneficial in other applications where power supply is more scarce.

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