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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.
91

Využití solární energie pro elektromobilitu / Use of solar energy for electromobility

Harant, Miroslav January 2019 (has links)
The thesis deals with the use of solar energy for electromobility. First, the potential of electromobility on the current market is theoretically discussed. This issue includes mainly the producers of electrically powered vehicles, the issue of electric energy storage and the real applications of fast charging and photovoltaic charging stations. In the next part, electric cars are analyzed, which use solar energy for their function and their efficiency is compared with the effiency of combustion engines. The main part of this thesis is the design of photovoltaic charging station for electric vehicles. The final part deals with the economic evaluation of the proposed charging station.
92

Využití solární energie pro elektromobilitu / Use of solar energy for electromobility

Harant, Miroslav January 2020 (has links)
The thesis deals with the use of solar energy for electromobility. First, the potential of electromobility on the current market is theoretically discussed. This issue includes mainly the producers of electrically powered vehicles, the issue of electric energy storage and the real applications of fast charging and photovoltaic charging stations. The second part of the diploma thesis deals with the measurement of electric car consumption and the evaluation of measurement results. In the next part, electric cars are analyzed, which use solar energy for their function and their efficiency is compared with the effiency of combustion engines. The main part of this thesis is the design of photovoltaic charging station for electric vehicles. The final part deals with the economic evaluation of the proposed charging station.
93

Fotovoltaický systém pro dobíjení elektromobilu / Photovoltaic System for Recharging Electric Vehicle

Krúpa, Lukáš January 2016 (has links)
This master thesis deals with use grid-off photovoltaic system for recharging electric vehicle. First is explained the principle of converting solar energy into electric energy and theoretically describes the components of the system. Furthermore, is presented a real application of the photovoltaic power plants in the world for recharging electric vehicles but also for other uses. The next section theoretically describes the grid-off system how it shout look like in real and there are presented the possibilities of choice of components. The main part is the actual construction of the grid-off system for recharging electric vehicle and measurement. The conclusion of this thesis is made up for the expected economic recovery of the entire system.
94

LIFE CYCLE ASSESSMENT of ERICSSON’s MANAGED RURAL COVERAGE SOLUTION / LIFE CYCLE ASSESSMENT of OFF-GRID SOLAR POWERED BASE STATION

KULTUR, BEGUM January 2013 (has links)
The total number of mobile subscriptions has been announced to reach 6 billion in the market, of which 4 billion are individual users. The rest of the people on earth are potential subscribers that mainly live in rural areas lacking mobile connectivity today. Many of these users do not have access to electricity and have 6 U.S. dollar per month (USD/month) of average revenue per person.   Referring to the year 2007, the telecommunication industry had a contribution of 0.6 percent of direct global carbon dioxide (CO2) or 0.4 percent of global carbon dioxide equivalent (CO2e). From 2007 to 2009, the number of off-grid radio base stations located in rural areas went up from 350,000 to 500,000. Nearly all of these sites use diesel generators and large amounts of fossil fuels during the operational stage. In addition the grid sites with diesel back-up were about 0.5 million in 2009. The financial and environmental consequences of the life cycle impact of the diesel fuel depleted can be significant. Adaptation of renewable energy has therefore become important for both environmental and economic reasons.   In this master thesis a Life Cycle Assessment of Ericsson’s Managed Rural Coverage (MRC) solution was made. Four main life cycle stages were included: manufacturing, transportation, operation and end-of-life treatment. MRC is an off-grid site solution consisting of electronic communication equipment (radio base station, base station controller, hub, cable) photovoltaic cells, battery, antenna, and constructions part (antenna pole, tower and foundation). This study also includes the satellite connection as well as Ericsson and operator activities in the assessment. The MRC distinguishes itself from the conventional base stations, by its significant decrease of energy consumption in its operational stage as well as the business model around the offering. The assessment in this thesis was carried out in accordance with data retrieved from an Ericsson’s pilot system in Dungunab, Sudan. The ISO 1404X series of LCA standards was followed and Gabi software w used to evaluate the results.   The carbon footprint was found to be 0.3 kg CO2e/subscriber for the pilot setup. These calculations were based on an assumption that each pilot site serviced 1000 users. The maximum number of subscribers can be about 3200, which would decrease the life cycle CO2 emissions per user by 2/3. According to the sensitivity analysis the maximum CO2 emissions for a conservative MRC scenario is less than 1 kg CO2e/subscriber. Although this figure represents a very conservative scenario, the result is low in comparison with an average GSM network which has an approximate carbon footprint of 15 kg CO2e/subscriber. It is important to note that the MRC is not intended to replace all conventional macro RBS sites due to limitations in performance and capabilities, but is rather a complement to conventional macro radio base station sites for applicable scenarios. / <p>Thesis registration number: EGI-2013-024MSC  EKV941</p>
95

Access to electricity and economic development : determinants of favorable impacts for households / Accès à l'électricité et développement économique : déterminants des impacts favorables pour les ménages

Millien, Arnaud 17 September 2019 (has links)
En 2018, environ un milliard de personnes vivaient sans électricité. Or l'extension des réseaux est confrontée à de nombreux défis qui compromettent la soutenabilité de l'électrification traditionnelle. Les Projets d'Electrification Décentralisée (PED) offrent désormais des solutions réalistes pour un accès à l'électricité hors réseau dans les pays en développement. Cette thèse explore le rôle de la demande de fiabilité du service d’électricité comme déterminant d’une extension durable du réseau, et l'efficacité de l'offre d’électricité décentralisée pour l’atteinte des objectifs du développement durable. Avec des données sur les coupures observées par les ménages au Kenya, le premier chapitre établit la préférence des ménages pour la fiabilité du service d'électricité, laquelle pourrait constituer le levier majeur d’une extension efficace du réseau. Dans le deuxième chapitre, une méta-analyse consolidant 112 évaluations de projets décentralisés montre que la technologie, la capacité et la gouvernance supportent les choix de conception les plus déterminants pour atteindre les objectifs du développement durable. Le troisième chapitre explore la gamme d'objectifs atteints par les pratiques de l’électrification décentralisée. Les plus efficaces sont celles qui adressent les utilisations productives et les services publics, ainsi que les micro-réseaux dans les zones éloignées, qui ont des impacts positifs sur l’information et la communication. La probabilité d'impacts positifs augmente avec la capacité des systèmes solaires individuels, qui favorisent la santé et l’éducation. / By 2018, about one billion people were living without electricity. The extension of electrical grids is facing many challenges that jeopardize the sustainability of traditional electrification. Decentralized Electrification Projects (DEP) now offer feasible solutions for offgrid access to electricity in developing countries. This thesis explores the role of the demand for reliability of the electricity service as a determinant of sustainable extension of the electrical grid, and the efficiency of electricity supply by DEP to achieve the sustainable development goals. With data on outages observed by households in Kenya, the first chapter establishes the households' preference for the reliability of electricity service, which could be the major lever for effective network expansion. In the second chapter, a meta-analysis consolidating 112 decentralized project evaluations shows that technology, capacity and governance support the design choices that are most critical to achieving the sustainable development goals. The third chapter explores the range of objectives achieved by decentralized electrification practices. The most effective are those that address productive uses and public services, as well as micro-networks in remote areas, which have positive impacts on information and communication. The likelihood of positive impacts increases with the capacity of solar home systems, which favor health and education.
96

Collective PV nano-grid for households in Linga Linga : A Minor Field Study in Mozambique

Diaz Hjelm, Wilma, Olsson, Ellie January 2022 (has links)
About a third of Mozambique’s population has access to electricity, and the same number in rural areas, where most of the population lives, is down to 5 %. Small-sized off-grid solutions are economical alternatives to increase the electricity access rate in rural areas, and solar power is a common energy source due to price and weather conditions. Still, the economical aspect is the main hindrance to an increased electrification rate in Africa. This report aims to investigate how to make electricity affordable, in a sustainable way, by answering the main research question “What is the capability, economically, socially, and technically, for a shared nano off-grid system in the village Linga Linga?”. This was done by performing a Minor Field Study in the village Linga Linga, in southern Mozambique, with the help of the non-profit organization Project Vita. A collective nano-grid photovoltaic (PV) system was installed to electrify three households, including nine houses and eleven people, where the wage earners are all women. Before the construction and installment of the PV system, the first round of two interviews was conducted to investigate the energy situation for the households. After the interviews, the main components of the energy system: PV panels, inverter, charge controller, batteries, and cables, were sized and purchased. The energy system was sized to cover an energy demand of eleven Light-Emitting Diode (LED)-lights, four 3 W and seven 5 W, lit all day and all night, and three outlets for charging cell phones eight hours a day. This corresponds to an energy demand of 1,369 Wh per day, and a maximum power demand of 77 W. The resulting system cost is 87,570 Mozambique Metical (MZN), or 1,400 United States Dollars (USD). When calculating the technical lifetime to be 20 years, three of the main components must be replaced. That results in a system cost of 122,470 MZN, 1,960 USD, and the cost per wage earner of the participating households is 4.3 % of the average Mozambican’s annual salary. After the system had been running for about a week, the second round of interviews was carried out. On the same occasion, the households were informed about the maintenance and usage of the system, and they were handed manuals and contracts to sign. The interviewees reported that they had been working for more hours a day, handicrafts being their main source of income, thanks to the electric lights. The women were positive about collective ownership and sharing electricity and stated that they prefer a collective system to separate ones, even for the same cost. The interviews showed that the energy demand was lower than what the system was sized for, meaning that a system designed for the actual energy demand would have been both cheaper and smaller. However, the energy behavior could change with time as society develops and the users get more familiar with electricity. No clear answers were obtained regarding the willingness to pay (WTP) for the system, and the interpretation is that the household, in their current situation, cannot consider buying an energy system comparable to the prototype built for this report, due to the system cost. A collective solar nano-grid in rural Mozambique is concluded to be a well-functioning solution and one of the more economical electrification alternatives. Although the prototype in this study was too expensive for the participating households to pay for by themselves, it could support sustainable development and open for possibilities like increased productivity and income. Moreover, it could be expanded by connecting more loads and upscaling to further cut the system cost per person and increase the societal benefits. / Ungefär en tredjedel av Moçambiques befolkning har tillgång till elektricitet, och motsvarande andel på landsbygden, där majoriteten av befolkningen bor, är 5 %. Mindre off-grid lösningar är ekonomiska alternativ för att elektrifiera landsbygden, där solkraft är en vanlig energikälla på grund av det relativt låga priset och väderförhållandena med goda förutsättningar. Den ekonomiska aspekten är dock fortfarande det främsta hindret för att öka Afrikas elektrifieringsgrad. Den här rapporten syftar till att undersöka hur elektricitet kan göras tillgänglig för alla, på ett hållbart sätt, genom att besvara frågeställningen ”Vad är möjligheterna, ekonomiskt, socialt, och tekniskt, för ett delat nano off-grid system i byn Linga Linga?”. Detta utreds genom att genomföra en Minor Fields Study i byn Linga Linga i södra Moçambique med hjälp av välgörenhetsorganisationen Project Vita. Ett nano-nätsystem drivet av solceller installerades, innefattande tre hushåll med nio hus och elva personer, med endast kvinnliga inkomsttagare. Innan byggnationen av solcellssystemet genomfördes intervjuer för att undersöka hushållens energisituation. De mest fundamentala systemkomponenterna; solcellspaneler, växelriktare, solcellsregulator, batterier och kablar, dimensionerades och införskaffades efter intervjuerna. Energisystemet utformades efter ett energibehov på elva Light-Emitting Diode (LED)-lampor, varav fyra 3 W och sju 5 W, tända dygnet runt, och tre uttag för att ladda mobiltelefoner åtta timmar om dagen. Detta motsvarar ett energibehov på 1,369 Wh per dag, och ett maximalt effektbehov på 77 W per dag. Den resulterande systemkostnaden är 87 570 Mozambique Metical (MZN), eller 1 400 United States Dollar (USD). För att räkna om systemkostnaden för en teknisk livslängd på 20 år måste tre av systemets huvudkomponenter bytas ut, vilket resulterar i en systemkostnad på 122 470 MZN, 1 960 USD. Kostnaden per inkomsttagare i de deltagande hushållen utgör då 4,3 % av den årliga moçambikiska medelinkomsten. När solcellssystemet varit i gång i en vecka utfördes en andra omgång intervjuer. I samband med detta informerades hushållen om skötsel och användning av systemet, och mottog manualer och kontrakt. Det framkom att kvinnorna, tack vare den elektriska belysningen, hade kunnat arbeta längre på kvällarna med sina hantverk - deras främsta inkomstkälla. De var positiva till det kollektiva ägandet av systemet och sade sig föredra ett delat system framför varsitt separat, även för samma kostnad per person. Intervjuerna visade att hushållens energikonsumtion var mindre än systemet var designat för. Ett system anpassat efter det verkliga energibehovet hade därmed blivit både mindre och billigare. Energianvändandet kan dock förändras i takt med samhällsutveckling och användarnas bekantskap med elektricitet. Inga tydliga svar angående betalningsvilja (WTP) för systemet mottogs, och tolkningen är att hushållen, i deras nuvarande situation, inte kan tänka sig köpa ett energisystem som är jämförbart med studiens prototyp, på grund av den höga systemkostnaden. Ett soldrivet kollektivt nano-nät på Moçambiques landsbygd bedöms vara en välfungerande elektrifieringslösning och ett av de mest ekonomiska elektrifieringsalternativen. Fastän studiens prototyp var för dyr för att de deltagande hushållen kan det ses stödja en hållbar utveckling genom att öppna upp för möjligheter såsom ökad produktivitet och inkomst. Systemet skulle även kunna expanderas genom att koppla in fler eller större last, och byggas i större skala för att dra ner systemkostnaden per person och öka samhällsnyttan.
97

Optimization of battery pack assembly of second life cells to reduce costs

Chowdry, Akash Prasad January 2022 (has links)
Batteries account for 50% of the overall cost of solar home systems (SHS). The battery packs degrade over time and when they reach 70% state of health (SOH), the whole SHS is discarded. In the predominantly rural off-grid context, battery replacements are expensive and impractical. The customers are often dozens of km away from any sales point. Furthermore, recycling schemes are often limited in the developing world, meaning that old batteries are sometimes discarded in unsafe ways. As the market grows, the environmental impact of this will only get larger. Solaris Offgrid, a premier name in the Solar Offgrid industry, is innovating two solutions designed to tackle this issue; a smart multi-battery packmanager and an easy to recycle battery pack design with cell by cell management. The current study is based on a lossless cell balancing design, where in the charge and discharge cycles of each cell in the string are monitored and to efficiently avoid overcharge and over-discharge. Implementing this strategy reduces the degradation of these batteries which extends the battery life of SHS. A sensitivity analysis is performed to analyze the environmental benefit gained by implementing lossless cell balancing. The thesis provides a literature study on the different battery terminologies, types of batteries used in SHS and, various cell-balancing techniques used today. This is followed by the design of a lossless cell balancing technique with minimal losses. / Batterierna står för 50 % av den totala kostnaden för solcellsanläggningar (SHS). Batteripaketen försämras med tiden och när de når 70 % av sitt hälsotillstånd kasseras hela solcellssystemet. På den övervägande landsbygden utanför elnätet är det dyrt och opraktiskt att byta ut batterierna. Kunderna befinner sig ofta tiotals kilometer från varje försäljningsställe. Dessutom är återvinningssystemen ofta begränsade i utvecklingsländerna, vilket innebär att gamla batterier ibland kasseras på ett osäkert sätt. I takt med att marknaden växer kommer miljöeffekterna av detta att bli allt större. Solaris Offgrid, som är ett ledande företag inom industrin för solcellsanläggningar, utvecklar två lösningar för att lösa detta problem: en smart batteripackförvaltare för flera batterier och en lätt återvinningsbar batteripackkonstruktion med cellvis hantering. Den aktuella studien bygger på en “förlustfri” cellbalanseringskonstruktion, där laddnings- och urladdningscyklerna för varje cell i strängen övervakas och effektivt undviker överladdning och överladdning. Genom att tillämpa denna strategi minskas degraderingen av dessa batterier, vilket förlänger batteritiden för SHS. En känslighetsanalys utförs för att analysera den miljöfördel som uppnås genom att införa förlustfri cellbalansering. Avhandlingen innehåller en litteraturstudie om olika batteriterminologier, typer av batterier som används i SHS och olika tekniker för cellbalansering som används idag. Detta följs av utformningen av en teknik för förlustfricellbalansering med minimala förluster.
98

Porovnání výkonnosti fotovoltaických panelů v podmínkách ČR / Comparison of different photovoltaic panels in CR

Červinka, Pavel January 2011 (has links)
This term paper deals about history, principle and use of photovoltaic panel. It describes their stucture and constantly improving properties of these panels. It outlines their gradual generational evolution from beginning to present. Then it describes the various systems involved on – grid and off – grid. It also describes and compares the photovoltaic panels and inverters from different global manufacturer. The end of this work deals about conditions of photovoltaic in the Czech republic and about Hady photovoltaic incubator, which belongs to the company Energ servis a.s. It presents a comparison of different local and the analysis of the impact of shading for the achievement of the photovoltaic panel. It makes mathematic models for calculation of the spacing range and calculation the power loss in a specific shade.
99

Förnybar energi på Svalbard

Andreasson, Tobias, Lindh, Emelia January 2018 (has links)
This degree thesis investigates the possibilities of producing food inside a container at Svalbard, using renewable energy and energy storage. The idea was to be able to place the container at remote places without the need of being connected to the grid. We chose Svalbard, where it is cold and the sun is shining 24 hours a day at summertime. In the winter the opposite occurs and the sun is absent from the sky. The work is divided into theoretical studies and results based on different calculations. Such as economical evaluations (LCOE), and simulations using the computer programs Matlab and PVsyst. We have investigated if solar power and wind power is suitable as energy sources. Options for storage were batteries, grid and hydrogen storage. Different cases with Photovoltaics- and wind power plants, with batteries or grid, were compared against each other. It is not possible to use the grid as storage. This resulted in different sizing of our cases, with no excess energy production. The result showed that a 5 kWp photvoltaic plant with dual axis tracking system, was the most profitable. The Pay off would be 14 years and the total profit 63 453 SEK. If it will become possible in the future to use the grid at Svalbard as storage, it will open up opportunites for bigger systems. This will lead to higher profit than with smaller ones. Our results show that it is now most profitable with solar power.
100

Autonomní dům aneb život grid-off / The Autonomous House or Living Grid-off

Chlebný, Radek January 2013 (has links)
This thesis deals with energy self-sufficiency focusing on the independence of the electric grid. Basic line emanating project form a concrete proposal for autonomous energy supply system. Emphasis is placed primarily on photovoltaic systems, electric energy accumulation and selection of individual components of such a system. Another important part of the thesis is also an economic evaluation of design variations. The thesis also deals with a market research, and thereof derived benefit assessment of each technology. The accompanying chapters are then devoted to the history of autonomous life style or classification of buildings according to their energy performance.

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