981 resultados para decentralized energy production


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Tavoitteena oleva hiilineutraali energiantuotanto muokkaa sähköntuotannosta sykkivämpää ja vaatii kulutuksen sopeutumista siihen. Tämä synnyttää tarpeen kansallisia markkinoita laajemmille sähkön vähittäismarkkinoille ja vaatii kuluttajilta aktiivisempaa roolia markkinoilla. Pohjoismaiset kantaverkkoyhtiöt ovat alkaneet valmistella pohjoismaisia sähkömarkkinoita sähkön vähittäiskaupan avaamiselle. Sähkön vähittäiskaupan avautuminen eri maiden välillä vaatii kansallisten markkinamenetelmien yhtenäistämistä varsinkin taseselvityksen ja tiedonvaihdon osalta. Tässä työssä tutkitaan Suomessa vuonna 2019 käyttöönotettavan keskitetyn tiedonvaihtojärjestelmän, Datahubin, vaikutuksia jakeluverkonhaltijalle. Vaikutuksia tarkastellaan Vantaan Energia Sähköverkot Oy:n näkökulmasta. Työssä kartoitetaan jakeluverkonhaltijan nykyisiä liiketoiminnan pääprosesseja ja niihin liittyvää tiedonvaihtoa eri markkinaosapuolten kanssa prosessien toteutuksessa. Lisäksi työssä esitellään jakeluverkonhaltijan nykyisten liiketoiminnan pääprosessien toteuttaminen Datahubissa. Jakeluverkonhaltijan liiketoiminnan nykyisiä pääprosesseja ja tiedonvaihtoa verrataan Datahubin kautta suoritettaviin prosesseihin. Työssä todettiin Datahubin korjaavan jakeluverkonhaltijan liiketoiminannan nykyisissä pääprosesseissa havaittuja ongelmia ja mahdollistavan prosessien tehostamisen. Datahub ei sinällään muuta nykyisiä jakeluverkonhaltijan liiketoimintaprosesseja merkittävästi, mutta mahdollistaa prosessien kehittämisen markkinoiden muutoksen mukana. Datahubin kokonaisvaltainen hyödyntäminen on toimijoiden itsensä käsissä, niiltä osin, kun sähkömarkkinalaki ei velvoita tiettyyn toimintamalliin. Jakeluverkonhaltijan liiketoimintaprosessien osalta suurin muutos kohdistuu jakeluverkonhaltijan taseselvitykseen, joka siirtyy kokonaisuudessaan Datahubin tehtäväksi. Datahub tulee kaventamaan jakeluverkonhaltijan roolia markkinapaikalla ja siksi jakeluverkonhaltijoiden tulisi kartoittaa liiketoiminnan laajentamisen tarvetta ja mahdollisuuksia tulevaisuudessa.

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Wind energy is one of the most promising and fast growing sector of energy production. Wind is ecologically friendly and relatively cheap energy resource available for development in practically all corners of the world (where only the wind blows). Today wind power gained broad development in the Scandinavian countries. Three important challenges concerning sustainable development, i.e. energy security, climate change and energy access make a compelling case for large-scale utilization of wind energy. In Finland, according to the climate and energy strategy, accepted in 2008, the total consumption of electricity generated by means of wind farms by 2020, should reach 6 - 7% of total consumption in the country [1]. The main challenges associated with wind energy production are harsh operational conditions that often accompany the turbine operation in the climatic conditions of the north and poor accessibility for maintenance and service. One of the major problems that require a solution is the icing of turbine structures. Icing reduces the performance of wind turbines, which in the conditions of a long cold period, can significantly affect the reliability of power supply. In order to predict and control power performance, the process of ice accretion has to be carefully tracked. There are two ways to detect icing – directly or indirectly. The first way applies to the special ice detection instruments. The second one is using indirect characteristics of turbine performance. One of such indirect methods for ice detection and power loss estimation has been proposed and used in this paper. The results were compared to the results directly gained from the ice sensors. The data used was measured in Muukko wind farm, southeast Finland during a project 'Wind power in cold climate and complex terrain'. The project was carried out in 9/2013 - 8/2015 with the partners Lappeenranta university of technology, Alstom renovables España S.L., TuuliMuukko, and TuuliSaimaa.

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The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

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Dissertação de mest. em Aquacultura e Pescas, Faculdade de Ciências do Mar e do Ambiente, Univ. do Algarve, 2006

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The importance of the United States' wood and wood byproducts as biomass feedstocks is increasing as the concern about security and sustainability of global energy production continues to rise. Thus, second generation woody feedstock sources in Michigan, e.g., hybrid poplar and hybrid willow (Populus spp.), are viewed as a potential source of biomass for the proposed biofuel ethanol production plant in Kinross, MI. It is important to gain an understanding of the spatial distribution of current feedstock sources, harvesting accessibility via the transportation infrastructure and land ownerships in order to ensure long-term feedstock extent. This research provides insights into the current extent of aspen and northern hardwoods, and an assessment of potential for expanding the area of these feedstock sources based on pre-European settlement conditions. A geographic information system (GIS) was developed to compile available geospatial data for 33 counties located within 150 miles of the Kinross facility. These include present day and pre-European settlement land use/cover, soils, road infrastructure, and land ownerships. The results suggest that a significant amount of northern hardwoods has been converted to other land use/cover types since European settlement, and the "scattering" of aspen stands has increased. Furthermore, a significant amount of woody biomass is available in close proximity to the existing road network, which can be effectively utilized as feedstock. Potential aspen and northern hardwoods restoration areas are identified in the vicinity of road networks which can be used for future woody feedstock production.

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The residual forest biomass (RFB) sector has been experiencing strong development at European level and particularly in Portugal mainly due to the increase of energy production from renewable sources. The aim of this study is to assess the environmental impacts of eucalyptus RFB chips production chain in Portugal. The environmental and economic impact comparison of the processes included in the production chain is presented as well. The environmental impacts were calculated by the life cycle assessment approach described in the ISO 14040 series of standards. The production chain assessed included all processes from eucalyptus forest until the delivery of RFB chips at the power plant. The main conclusion of this study is that eucalyptus wood production is the process that presents the greatest environmental impact through the product life cycle.

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Because of global warming the energy production development has progressed towards more renewable energy sources. Biomass has great potential in this matter and pellet is already a big market that has increased seven times the past decade. A periodically strained woodchip resource market and statements of short supply in the future has got actors exploring opportunities with other commodities. Grasses such as Canary grass has shown great potential in this matter and in this study a wetland grass is tested as an additive, 0,5, 1,0, 1,5, and 1,9%, with spruce woodchips. The test production series was performed at a production unit located at the department of environmental and energy system at Karlstad University, Karlstad. Quality was controlled accordingly to the European standard and parameters such as energy consumption, moisture content, mechanical durability and bulk density was tested. For comparison, a sample with only spruce wood chips was produced, and a sample containing 1% of a commonly used additive, potato starch. The results showed that a decrease in energy consumption with 14% when 2% wetland grass was added, part of the decline may be due to the increased production flow compared with the reference sample. The positive effects on decrease in energy consumption, that 1% potato starch results in, is equal to reults from 1% wetlandgrass. This indicates lubricating properties in wetlandgrass. This is attributed to that herbaceous plants have a high content of extracts such as waxes and that they cause less friction in the press. Tests also showed that pellet with wetland grass did not qualify the European standard in terms of mechanical durability. Extracts can form a weak boundary layer in the pellet and cause this. A possible trend shows a better mechanical durability with more grass in pellets. The presence of different size of particles can be a reason. Moisture content qualifies according to the European standard but is below optimum 8%. This despite to relatively high moisture content in the mixer. Higher moisture content in the press would certainly result in a generally higher quality. Suggestions for future studies are to produce pellets with greater distribution on the wetland grass added, to easier interpret a connection. Also examine the extracts behavior with different moisture content. For a sustainable development accordingly renewable energy it is important to ensure the future commodity market for pellets. Further studies should be performed to help the development of alternative raw materials in conjunction with pellet production.

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Tradicionalmente, la consolidación de la seguridad energética en Estados Unidos se ha mostrado como un asunto de seguridad nacional. En especial, la escasez de recursos energéticos ha sido vista como un problema existencial que requiere de medidas de emergencia en el marco de un proceso de securitización. Sin embargo, esta investigación surgiere que el tema ha sido mayoritariamente politizado a inicios del siglo XXI. Quizá este proceso de securitización tan solo fue implícitamente planteado con ocasión de la invasión a Irak en 2003, en la medida en que dicha intervención pudo haberse inspirado por la necesidad de derrocar a un régimen que había impedido el acceso estadounidense a recursos petroleros iraquíes. En este orden de ideas, la investigación analiza las políticas de seguridad energética de los gobiernos de George W. Bush y Barack H. Obama con el propósito de entender el grado en el que estas estuvieron vinculadas a sus respectivas agendas de seguridad nacional.

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Anaerobic digestion (AD) of wastewater is a very interesting option for waste valorization, energy production and environment protection. It is a complex, naturally occurring process that can take place inside bioreactors. The capability of predicting the operation of such bioreactors is important to optimize the design and the operation conditions of the reactors, which, in part, justifies the numerous AD models presently available. The existing AD models are not universal, have to be inferred from prior knowledge and rely on existing experimental data. Among the tasks involved in the process of developing a dynamical model for AD, the estimation of parameters is one of the most challenging. This paper presents the identifiability analysis of a nonlinear dynamical model for a batch reactor. Particular attention is given to the structural identifiability of the model, which considers the uniqueness of the estimated parameters. To perform this analysis, the GenSSI toolbox was used. The estimation of the model parameters is achieved with genetic algorithms (GA) which have already been used in the context of AD modelling, although not commonly. The paper discusses its advantages and disadvantages.

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A exigência energética global está mais orientada para a utilização das fontes de Energias Renováveis (FERs), comprometendo e garantindo um desenvolvimento sustentável. Este trabalho tem como objetivo contribuir para o atingir das metas do PED 2011-2030, no que refere à utilização das FER, em particular do potencial eólico em Timor-Leste. Timor-Leste tem apresentado um grande interesse na política de aproveitamento de FER para alcançar a meta de longo prazo de PED 2030, comprometendo-se com o desenvolvimento sustentável através de ERs. Este trabalho pretende contribuir em particular com o estudo do aproveitamento de energia eólica. Com base no clima do vento de longo termo entre 2004 – 2012, da estação meteorológica (EM) de Díli e conjugando estes com os dados da campanha experimental de Martifer cedidos, de Dezembro 2008 - Novembro 2009, obteve-se o coeficiente de variabilidade (Cvariab.) inter-anual. Foi assim possível construir o mapa médio do vento de longo termo, com modelo atmosférico de mesoscala, numa resolução refinada de 3×3 km. Para a identificação dos locais mais favoráveis do vento, foi utilizado o modelo ArcGIS para georreferenciação do recurso. A filtragem das restrições e os constrangimentos do terreno permitiu construir o mapa do vento sustentável de Timor-Leste, por distritos, subdistritos, sucos, do enclave de Oecússi e a ilha de Atauro, o que conduziu à hierarquização de cinco zonas favoráveis (zona 1 - 5). A contribuição para o plano energético de Timor-Leste consiste em duas fases: - a 1ª fase o aproveitamento eólico em três PEs nas zonas monitorizadas (3 e 5) oriundo de dados cedidos pela Martifer, contabilizou-se um total de 424.694 MWh de produção de energia anual, tendo-se verificado o custo normalizado de energia (LCOE) no valor médio calculado de 0,046 €/kWh; - na 2ª fase a construção de acesso e o desenvolvimento de PEs nas zonas 1, 2 e 4 para o Cenário de Max-Renovável. Assim sendo, viabilizam a "Perspetiva de Utilização da Energia Eólica" no quadro do PED 2011 - 2030 de Timor-Leste, que viria reduzir o custo de produção de energia atual, e a emissão de CO2; Abstract: Prospects of Using Wind Energy in Timor-Leste The demand for global energy is more focused on the use of Reneweable Energy sources (REs), ensuring and committing itself to sustainable development. This study was prompted by the wish to contribute to the achievement the goals of the Strategic Development Plan (PED 2011-2030) regarding the use of REs, particularly the wind energy in Timor-Leste. Timor-Leste has presented a great interest in the use of renewable energy sources policy to achieve the long term goal of the PED 2030, committing to a sustainable development through renewable energy. This thesis intends to contribute in particular with the study of the use of wind energy. Based on the long term wind climate between 2004 and 2012 of the Díli weather station and combining these data with the Martifer campaign experimental data of December 2008 - November 2009, the interannual variation coefficient (Cv) was obtained. Thus, it was possible to build the map of long term average wind with atmospheric mesoscale model in a refined resolution of 3×3 km. The ArcGIS model was used for the identification of the most favorable locations of the wind for its georeferencing. The constraining of filtering and the constraints of the terrain allowed to construe the sustainable wind map of Timor-Leste in distritos, subdistritos, sucos, and also of the enclave of Oecussi and Atauro island, which led to the ranking of five favorable areas (zone 1-5) for an immediate experimental campaign of wind characterization and utilization of this resource in wind parks. The contribution to Timor-Leste's energy plan consists of two phases: - the first phase of three wind farms in zone (3 and 5) from data provided by Martifer, a total of 424,694 MWh, and levelyzed cost of electricity (LCOE) in the calculated average value of 0.046 €/kWh; - in the second phase the construction of access and development of wind farms in zones 1, 2 and 4 for the Max-Renewable Scenario. As such, they make possible the "Perspective of Wind Energy Use" in Timor Leste’s PED 2011 - 2030, which would reduce current energy production costs and CO2 emissions.

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The need to use renewable energy sources, due to the massive production of pollution for the energy production, has led to the development of new technologies for the use of solar energy. The purpose of this thesis project is to synthesize and characterize new thiophene-based polymeric materials processable in water, a green solvent, for the construction of organic solar cells, promising and versatile devices used for the production of electric energy. For this, a highly regioregular polymer was synthesized through GRIM polymerization (Grignard Metathesis Polymerization) on which a study was performed to identify the optimal reaction time.

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L’energia da onda potrebbe assumere un ruolo fondamentale per la transizione energetica durante i prossimi decenni, grazie alla sua continuità nel tempo molto superiore rispetto ad altre risorse rinnovabili e alla sua vasta distribuzione nello spazio. Tuttavia, l’energia da onda è ancora lontana dall’essere economicamente sostenibile, a causa di diverse problematiche tecnologiche e alle difficoltà finanziarie associate. In questa ricerca, si è innanzitutto affrontata una delle maggiori sfide tecniche, nello specifico la progettazione e modellazione di sistemi di ancoraggio per i dispositivi galleggianti, proponendo possibili soluzioni per la modellazione numerica di sistemi di ancoraggio complessi e per l’ottimizzazione dei dispositivi stessi. Successivamente sono state analizzate le possibili sinergie strategiche di installazioni per lo sfruttamento della energia da onda con altre risorse rinnovabili e la loro applicazione nel contesto di aree marine multiuso. In particolare, una metodologia per la valutazione della combinazione ottimale delle risorse rinnovabili è stata sviluppata e verificata in due diversi casi studio: un’isola e una piattaforma offshore. Si è così potuto evidenziare l’importante contributo della risorsa ondosa per la continuità energetica e per la riduzione della necessità di accumulo. Inoltre, è stato concepito un metodo di supporto decisionale multicriteriale per la valutazione delle opzioni di riuso delle piattaforme offshore alla fine della loro vita operativa, come alternativa al decommissionamento, nell’ottica di una gestione sostenibile e della ottimizzazione dell’uso dello spazio marino. Sulla base dei criteri selezionati, l’inclusione di attività innovative come la produzione di energia da onda si è dimostrata essere rilevante per rendere vantaggioso il riuso rispetto al decommissionamento. Numerosi studi recenti hanno infatti sottolineato che, nell’ambito della “crescita blu”, i mercati come l’oil&gas, le attività offshore e le isole stimoleranno lo sviluppo di tecnologie innovative come lo sfruttamento dell’energia da onda, promuovendo la sperimentazione e fornendo un importante contributo all’avanzamento tecnico e alla commercializzazione.

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The world grapples with climate change from fossil fuel reliance, prompting Europe to pivot to renewable energy. Among renewables, biomass is a bioenergy and bio-carbon source, used to create high-value biomolecules, replacing fossil-based products. Alkyl levulinates, derived from biomass, hold promise as bio-additives and biofuels, especially via acid solvolysis of hexose sugars, necessitating further exploration. Alkyl levulinate's potential extends to converting into γ-valerolactone (GVL), a bio-solvent produced via hydrogenation with molecular-hydrogen. Hydrogen, a key reagent and energy carrier, aids renewable energy integration. This thesis delves into a biorefinery system study, aligning with sustainability goals, integrating biomass valorization, energy production, and hydrogen generation. It investigates optimizing technologies for butyl levulinate production and subsequent GVL hydrogenation. Sustainability remains pivotal, reflecting the global shift towards renewable and carbon bio-resources. The research initially focuses on experimenting with the optimal technology for producing butyl levulinate from biomass-derived hexose fructose. It examines the solvolysis process, investigating optimal conditions, kinetic modeling, and the impact of solvents on fructose conversion. The subsequent part concentrates on the technological aspect of hydrogenating butyl levulinate into GVL. It includes conceptual design, simulation, and optimization of the fructose-to-GVL process scheme based on process intensification. In the final part, the study applies the process to a real case study in Normandy, France, adapting it to local biomass availability and wind energy. It defines a methodology for designing and integrating the energy-supply system, evaluating different scenarios. Sustainability assessment using economic, environmental, and social indicators culminates in an overall sustainability index, indicating scenarios integrating the GVL biorefinery system with wind power and hydrogen energy storage as promising due to high profitability and reduced environmental impact. Sensitivity analyses validate the methodology's reliability, potentially extending to other technological systems.

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The current environmental and socio-economic situation promotes the development of carbon-neutral and sustainable solutions for energy supply. In this framework, the use of hydrogen has been largely indicated as a promising alternative. However, safety aspects are of concern for storage and transportation technologies. Indeed, the current know-how promotes its transportation via pipeline as compressed gas. However, the peculiar properties of hydrogen make the selection of suitable materials challenging. For these reasons, dilution with less reactive species has been considered a short and medium solution. As a way of example, methane-hydrogen mixtures are currently transported via pipelines. In this case, the hydrogen content is limited to 20% in volume, thus keeping the dependence on natural gas sources. On the contrary, hydrogen can be conveniently transported by mixing it with carbon dioxide deriving from carbon capture and storage technologies. In this sense, the interactions between hydrogen and carbon dioxide have been poorly studied. In particular, the effects of composition and operative conditions in the case of accidental release or for direct use in the energy supply chain are unknown. For these reasons, the present work was devoted to the characterization of the chemical phenomena ruling the system. To this aim, laminar flames containing hydrogen and carbon dioxide in the air were investigated experimentally and numerically. Different detailed kinetic mechanisms largely validated were considered at this stage. Significant discrepancies were observed among numerical and experimental data, especially once a fuel consisting of 40%v of hydrogen was studied. This deviation was attributed to the formation of a cellular flame increasing the overall reactivity. Hence, this observation suggests the need for combined models accounting for peculiar physical phenomena and detailed kinetic mechanisms characterizing the hydrogen-containing flames.

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In the framework of the energy transition, the acquisition of proper knowledge of fundamental aspects characterizing the use of alternative fuels is paramount as well as the development of optimized know-how and technologies. In this sense, the use of hydrogen has been indicated as a promising route for decarbonization at the end-users stage in the energy supply chain. However, the elevated reactivity and the low-density at atmospheric conditions of hydrogen pose new challenges. Among the others, the dilution of hydrogen with carbon dioxide from carbon capture and storage systems represents a possible route. However, the interactions between these species have been poorly studied so far. For these reasons, this thesis, in collaboration between the University of Bologna and Technische Universität Bergakademie of Freiberg in Saxony (Germany), investigates the laminar flame of hydrogen-based premixed gas with the dilution of carbon dioxide. An experimental system, called a heat flux burner, was adopted ad different operating conditions. The presence of the cellularity phenomenon, forming the so-called cellular flame, was observed and analysed. Theoretical and visual methods have allowed for the characterization of the investigated flames, opening new alternatives for sustainable energy production via hydrogen transformation.