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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.
1

Techno-economic study of second-life EV batteries as alternative energy storage and comparison with lead-acid and new Li-ion batteries in off-grid PV systems

Arumugam, Vijay January 2022 (has links)
The global EV stock is expected to increase from 7.2 million in 2019 to nearly 140 million vehicles by 2030. So, the demand for the battery also increases due to the increase in the number of EVs. In any EV, battery degradation is an unavoidable phenomenon and EV batteries are assumed to arrive at their end-of-life in EV application when the state of health reaches 80 %, repurposing the eligible EV batteries after end of first life is expected to extend their lifetime by another 5-15 years in the second life applications.  This thesis aims to conduct a techno-economic study on the usage of second life EV batteries as an alternative storage option in off-grid PV systems compared to lead-acid batteries and new Li-ion batteries. A single-family house with an annual demand of 2245 kWh/year located in Athens was chosen as the primary location, the off-grid PV system is pre-sized for Athens and based on the pre-sizing results and what is state of art in the market. The system components were chosen for system design (4 kW bi-directional inverter, 2.9 kW PV array, 7.2 kW genset and three battery bank options i.e., 16.5 kWh of lead-acid, 8 kWh new Li-ion and 12.6 kWh of second life EV battery). PV off-grid system with different storage options is simulated using HOMER for both locations and the results are compared.   The simulation results show that the designed off-grid PV system can reach a solar fraction of 90 % in Athens and 73 % in Gotland when 16.5 kWh of lead-acid batteries are used with an allowed depth of discharge of 50 %. When a new Li-ion battery of 8 kWh with an allowed depth of discharge of 80 % is used then the achievable solar fraction is 84 % in Athens and 71 % in Gotland, When the second life EV battery of 12.6 kWh with an allowed depth of discharge of 60 % is used then the achievable solar fraction is 90 % in Athens and 74 % in Gotland. Sensitivity analysis is performed on the depth of discharge and results showed that the solar fraction can be increased by allowing the battery to discharge more, but it also decreases the battery lifetime.   The simulation results also show that the net present cost was lower in Athens for all the reference cases compared to Gotland. Net present cost and levelized cost of electricity for the off-grid system are 25.3 k€, 0.9 €/kWh in Athens and 29.2 k€, 1.0 €/kWh in Gotland when a lead-acid battery is used. When a new Li-ion battery is used then 26.2 k€, 0.9 €/kWh in Athens and 29.3 k€, 1.0 €/kWh in Gotland, when the second life EV battery is used then 26.7 k€, 0.9 €/kWh in Athens and 30.7 k€, 1.1 €/kWh in Gotland.   Overall, the net present cost and levelized cost of electricity are lower in Athens in all cases compared to Gotland. For the reference house in Athens, lead acid battery system has shown slightly lower net present cost than new Li-ion battery and second life EV battery. For the reference house in Gotland, both lead acid battery and new Li-ion battery system have shown similar net present cost and they are slightly lower than second life EV battery.   Also, the second life EV battery levelized cost of electricity is fairly comparable to the new Li-ion and lead acid battery system. In future, the massive inflow of used batteries from EV are expected to be available on the market for the second life application at a lower price than today. Thus, in future, second life EV batteries can become economically viable.
2

Off-grid Wind Power Systems: Planning and Decision Making

El Zein, Musadag January 2019 (has links)
There are definitely many reasons for choosing off-grid wind power systems. Few key ones involve the positive enhancement of societies, economies and natural environments. From a project developers’ perspective these systems provide a large potential market, which can cover a wide range of applications with relatively reasonable costs.  In spite of this, many challenges may interfere with the diffusion and the success of such systems. In the report we discuss the various factors affecting  the implementation of off-grid wind power systems and demonstrate some of the challenges project developers may be facing during the planning stage. Some of these include the acceptance of stakeholders (local inhabitants in particular) and the securing of the financing of the projects.  Another noted challenge lying outside the control of project developers was found to be the absence of encouraging policies and incentives. As a conclusion the thesis provides a set of self-interpreted recommendations along with a flow chart. The concluded summary indicates some key factors that project developers should be aware of and careful when dealing with, these which include: The choice of the site, verification of projects’ economics along with the securing of a convenient finance. The recommendations also point out the great advantage in having local developers as these tend to be more capable in building relations with the local citizens and politicians.
3

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.
4

Modelo de unidade habitacional rural unifamiliar autossuficiente em geração e consumo de energia elétrica / HOUSING UNIT MODEL RURAL UNIFAMILIAR SELF-SUFFICIENT IN GENERATION AND ELECTRICITY CONSUMPTION

Mota, Victor Nogueira Teixeira 31 March 2016 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-01T19:08:36Z No. of bitstreams: 1 VictorNogueiraTeixeiraMota.pdf: 10378249 bytes, checksum: 880b9599e08ab5e5f7a0bd7c97ddcb71 (MD5) / Made available in DSpace on 2017-06-01T19:08:36Z (GMT). No. of bitstreams: 1 VictorNogueiraTeixeiraMota.pdf: 10378249 bytes, checksum: 880b9599e08ab5e5f7a0bd7c97ddcb71 (MD5) Previous issue date: 2016-03-31 / Housing with dignity in Brazil still does not reach the entire population. There are people who live in properties in precarious situations of safety and health. Besides not having a comfortable shelter to live, many people have no access to electricity and precious to the sustainable development of the population. This work is discussed and developed a rural housing model that meets low cost criteria, environmental comfort for users and energy efficiency. The National Program for Rural Housing the federal government aims to eradicate substandard housing, but housing conditions the granting of the prior existence of electricity in the community, which in many cases is isolated and does not have a utility power network. This work is raising questions about the rural electrification through a comparative analysis of models and incentive policies for PV solar energy in Brazil and worldwide, identifying strengths and to improve the energy matrix of the country, serving isolated households in urban centers and ensuring quality of life for these citizens. The main motivation is to give an indication for rural housing policies, in order to facilitate the extension of this benefit to under served rural sectors by electrification programs, whose condition is mandatory for eligibility of rural housing programs. The results encourage the spread of solar PV technology as an alternative and promising renewable source in Brazil. / Habitação com dignidade no Brasil ainda não atinge a totalidade da população. Há pessoas que habitam imóveis em situações precárias de segurança e salubridade. Além de não terem um abrigo confortável para residir, muitas pessoas não tem acesso a energia eletrica, bem precioso para o desenvolvimento sustentável da população. Neste trabalho é discutido e desenvolvido um modelo de habitação rural que atende critérios de baixo custo, de conforto ambiental para os usuários e de eficiência energética. O Programa Nacional de Habitação Rural do governo federal visa a erradicação de habitações precárias, porém, condiciona a concessão da moradia a existência prévia de energia elétrica na comunidade, a qual em muitos casos e isolada e não possui rede de energia da concessionária. Este trabalho vem levantar questões acerca da eletrificação rural, através de uma análise comparativa dos modelos e políticas de incentivo a energia solar fotovoltaica no Brasil e no mundo, identificando pontos positivos e a melhorar a matriz elétrica do país, atendendo domicílios isolados dos centros urbanos e garantindo qualidade de vida a estes cidadãos. A principal motivação é dar um indicativo para as políticas de habitação rural, de forma a viabilizar a extensão deste beneficio para setores rurais desassistidos por programas de eletrificação, cuja condição é mandatória para elegibilidade de programas de habitação rural. Os resultados obtidos fomentam a disseminação da tecnologia de energia solar fotovoltaica como fonte renovável alternativa e bastante promissora no Brasil.

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