Tesis: "Storage of intermittent energies"

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Gils, Hans Christian [Verfasser], and André [Akademischer Betreuer] Thess. "Balancing of intermittent renewable power generation by demand response and thermal energy storage / Hans Christian Gils. Betreuer: André Thess." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1081367563/34.

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Goemaere, Loïc. "Comparaison de la production de trois technologies différentes de panneaux solaires en fonctionnement réel avec suivi du soleil et intégration de batteries lithium innovantes adaptées au stockage des énergies intermittentes." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20211/document.

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Dans une vision de développement durable et d'indépendance énergétique visant l'intégration massive des énergies renouvelables à moyen terme dans le mix énergétique, les travaux menés au cours de cette thèse se sont axés sur deux thématiques :- d'une part, la comparaison de la production de trois technologies différentes de panneaux solaires (silicium, silicium avec concentration, CdTe) en fonctionnement réel dans une centrale photovoltaïque au sol dotée du suivi deux axes de la course du soleil ;- d'autre part et étant donné la nature intermittente de l'énergie photovoltaïque et son non-synchronisme avec la consommation, le développement et l'intégration de batteries à base de lithium comme moyen de stockage électrochimique de l'énergie photovoltaïque. L'approche est novatrice et a permis l'étude de nouveaux composés d'électrodes étudiés sous contraintes photovoltaïques réelles et utilisant différentes stratégies de restitution de l'énergie en vue du déploiement prochain des réseaux intelligents. Les simulations portent sur des accumulateurs de petites tailles classiquement utilisés dans les laboratoires de recherche mais préfigurant ce qui pourra être construit à plus grande taille In a vision of sustainable development and energy independence aiming at the massive integration of the medium-term renewable energies in the energy mix, the research works are centered on two themes:- On one hand, the comparison of the production of three technologies different from solar panels (silicon, silicon with concentration, CdTe) installed into a photovoltaic power plant with 2-axes sun tracking;- On the other hand and given the intermittent nature of the photovoltaic energy and its non-simultaneity with the consumption, the development and the integration of batteries with lithium as means of electrochemical storage of the photovoltaic energy. The approach is innovative and allowed the study of new compounds of electrodes studied under real photovoltaic constraints and using various strategies of return of the energy with the aim of the next deployment of the intelligent networks. The simulations concern batteries of small sizes classically used in research laboratories but prefiguring what can be built in bigger size

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3

Al-imarah, Amena, and Elin Stenberg. "Tillämpning av batterilager som energitjänsten lastutjämnare : En studie om batterilagring för en medelstor abonnent i Varberg Energis elnät." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-33263.

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Arbetet Tillämpning av batterilager som energitjänsten lastutjämnare är en litteraturstudie och en kvantitativ studie. I studien har driftkarakteristiken år 2015 hos en matvarubutik legat till grunden. Arbetet har syftat i att besvara frågan kring ett batterilagers lämplighet som agerade för lastutjämning. För att ta reda på det har batterilagersegenskaper kartlagts och dimensionering gjorts utifrån två olika driftfall. En ekonomisk besparingspotential har även beräknats utifrån de bägge driftfallen. Driftfallen har valts att kallas teknisk dimensionering och ekonomisk dimensionering. De tekniska dimensionerade lagerna har en lager storlek om 617 kWh och 555kWh vilket motsvarar 7,1% respektive 5,8% av den dagliga energianvändningen. För de ekonomiskt dimensionerade lagerna har en lager storlek om 597 kWh och 233kWh vilket motsvarar 6,8% respektive 2,8% av den dagliga energianvändningen. Den ekonomiska besparingspotentialen blir som störst för en blandad körning av de bägge driftfallen. Trotts att besparingspotentialen är uppskattade under ideala förhållanden med varken förluster eller degraderad prestanda lönar det inte sig att investera i ett batterilager för att enbart utföra tjänsten effektutjämning idag. Investering i ett batterilager för effektutjämning har potential att bli lönsam först när den kan tillgodose fler energitjänster eller när alternativkostnaden är förhöjd. This thesis, is a study of battery energy storage and its use as energy source and smoothening of power fluctuation. Studies have been made as a systematic review and a quantitative study. The study has consisted of analysing the power characteristic from a supermarket in the city of Varberg during year 2015. The object has been to evaluate the energy storage and the power smoothing qualities. Therefore the battery energy storages characteristics have been evaluated in this systematic review. For the quantitative study, calculations of the energy storage sizes were made for two separate operation modes. The two different operation modes were named technical dimensioning and economic dimensioning. The function of the technical dimensioning was to smooth the power outlet from the grid, while the function of the economic dimensioning was to enable the supermarket to buy more energy during low-price hours. Based on monthly power characteristics, each dimensioning gave as a result two energy storage possibilities, one in medium and one in small size. The technical dimensioning resulted in battery energy storage of the sizes 617 kWh and 555kWh which is comparable to 7,1% and 5,8% of the daily energy usage of the supermarket. The economic dimensioning resulted in battery energy storage of the sizes 597 kWh and 233kWh which is comparable to 6,8% and 2,8% of the daily energy usage of the supermarket. For optimizing the economic savings, a variation of technical and economic operation mode are needed, depending on calculated power usage through the day and elspot prices. The study shows that a battery storage is difficult to finance. The calculated economic savings were estimated during ideal conditions and without power loss or loss in performance. As a conclusion from this study a battery storage may have a good payback if there are several energy services to be filled.

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Clerjon, Arthur. "Analyse et modélisation des impacts du développement des énergies renouvelables intermittentes sur le système électrique Français : Etude du potentiel du stockage de l’électricité, et de la complémentarité avec la chaleur." Thesis, Université Grenoble Alpes, 2021. http://www.theses.fr/2021GRALI022.

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La France affiche une volonté de développer massivement les énergies renouvelables intermittentes – éolien et photovoltaïque - tout en diminuant la part des sources pilotables, ici le nucléaire. Ce changement de paradigme implique de repenser la gestion des systèmes énergétiques. En effet, l’intermittence des renouvelables génère un besoin de flexibilité à différentes échelles de temps, de la journée à l’année. Ne pouvant plus se reposer sur la flexibilité des moyens pilotables, cette thèse questionne le potentiel d’autres moyens pour y répondre : stockage d’électricité, surdimensionnement de la production et réseaux de chaleur.Face à la nécessité d’une approche système, des modèles simples ont été développés pour affiner la compréhension des interdépendances entre production et stockages. Les indicateurs optimisés sont économiques (€) mais aussi environnementaux : énergie grise et émission de gaz à effet de serre sur l’ensemble du cycle de vie. Les performances des systèmes considérés sont celles d’aujourd’hui et leur développement est limité par les ressources et l’espace disponibles. Sans rentrer dans le détail précis du fonctionnement de chaque technologie, cette approche physique donne les domaines de fonctionnement optimaux des différentes technologies, et les cas difficiles pour lesquels les solutions manquent encore.Dans un premier temps, le besoin en flexibilité généré pourdifférents taux de pénétration de l’intermittence est quantifié pour plusieurs échelles de temps. Cela permet de comparer le potentiel de différentes technologies de stockage d’électricité à chacune de ces échelles pour mettre en phase production et consommation. Les résultats montrent que les temps longs –-- typiquement le stockage saisonnier –-- sont ceux qui demandent les plus gros investissements pour une faible rentabilité. Ensuite, les mécanismes de compétition entre plusieurs stockages et le surdimensionnement sont analysés pour montrer dans quel cas les optimums utilisent des solutions complémentaires. L’étude aborde alors le potentiel du couplage entre le réseau électrique et le réseau de chaleur comme moyen de flexibilité, notamment pour la gestion des besoins longs termes.Ce travail de thèse se focalise à l’échelle Française, bien que la méthodologie soit applicable ailleurs France aims to massively develop intermittent renewable energies --- wind and photovoltaic --- while reducing the share of dispatchable sources, in this case, nuclear power. This paradigm shift implies rethinking the management of energy systems. Indeed, renewables' variable nature generates a need for flexibility on different time-scales, from day to year. As dispatchable means' flexibility can no longer be relied on, this thesis questions the potential of other means to meet this need: electricity storage, oversized production and heating networks.Faced with the need for a systemic approach, we developed simple models to enhance the understanding of the interdependencies between production and storage. The optimized indicators are economic (€), but also environmental: embodied energy and greenhouse gas emissions over the entire life cycle. The performances of the systems considered are those of today and their development is limited by resource and space availability. Without going into the precise details of how each technology works, this physical approach points out optimal operation areas for the different technologies and the difficult cases for which solutions are still lacking.First, the need for flexibility generated for different intermittency penetration rates is quantified for several time scales. It enables us to compare the potential of different electricity storage technologies --- at each of these scales --- to bring production and consumption in phase. The results show that long time-scales --- typically seasonal storage --- require the largest investments for low profitability. The competition mechanisms between several storages and oversizing are then analyzed. It shows how the optimum solutions use complementary flexibility means. The study then addresses the potential of coupling between the electrical grid and the heating grid as a means of flexibility, particularly for the management of long-term needs.This thesis work focuses on the French scale, although the methodology is applicable elsewhere

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Roobottom, Helen Kay. "Lattice potential energies and theoretical applications." Thesis, University of Warwick, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340053.

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Abdelouadoud, Seddik Yassine. "Intégration des énergies renouvelables au réseau de distribution d'électricité." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0071/document.

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Afin de lutter contre le changement climatique et de préserver les ressources naturelles, de nombreux pays ont mis en place des politiques plus ou moins ambitieuses de développement des énergies renouvelables électriques à court et moyen terme, tandis que, en parallèle, des scénarii de prospective à long terme envisagent un approvisionnement électrique majoritairement d'origine renouvelable. Certaines de ces énergies sont intermittentes et non contrôlables et, du fait des faibles économies d'échelle dont elles bénéficient, peuvent être développées de manière décentralisée, intégrées au bâtiment et raccordées au réseau de distribution, à l'opposé des moyens de production actuels. Concomitamment, les pointes de consommation augmentent à un rythme soutenu et obligent les gestionnaires de réseaux et les producteurs/fournisseurs à toujours plus d'investissements dans des moyens de production et de transport qui ne seront utilisés que pendant un faible nombre d'heures par an.Les changements décrits ci-dessus vont avoir un impact sur les trois grands objectifs de la planification et de la gestion du système électrique : minimiser le coût global, assurer la sûreté de l'approvisionnement et garantir la qualité de la fourniture. Si on analyse le fonctionnement actuel du système, les transformations à venir et les possibilités offertes par l'intégration de solutions de contrôle et de gestion (compteurs électriques communicants, transformateurs régleur en charge, onduleurs PV avec gestion de réactif, stockages, etc.) au réseau de distribution, il est possible de mettre en évidence trois grands domaines d'application - et donc de valorisation - pour celles-ci. Il s'agit du déplacement temporel d'énergie, de la fourniture de services auxiliaires (régulation et suivi de charge, réserve ou gestion de tension, par exemple) et de l'optimisation de la planification et de la gestion du réseau (évitement et/ou retardement d'investissement).Cependant, l'ensemble des procédures et méthodes de planification et d'opération actuel est basé sur l'hypothèse d'une production centralisée et d'un réseau de distribution passif. Dans ce contexte, cette thèse contribue au développement d'une méthode de simulation d'un réseau de distribution actif en proposant trois avancées: une méthode de décomposition-coordination permettant la simulation intégrée du système centralisé et du réseau de distribution, un algorithme de résolution du problème des flux optimaux dans le réseau de distribution et un critère de criticité diminuant les besoins en capacité de calcul de la simulation si elle est employé dans un cadre de planification Many countries have set up mechanism support in favor of renewable energy development at a short or long term, while, in parallel, long-term scenarios of predominantly renewable energy provisioning are studied. Some of these energies are intermittent and non-dispatchable and, due to the low economies of scale they exhibit, can be deployed in a decentralized manner, integrated in buildings and connected to the distribution system.However, the methods and tools currently used to plan and operate the power system rely on hypothesis of centralized generation and passive distribution network. In this context, this thesis contributes to the development of a method aimed at simulated an active distribution network by proposing three novel approaches: a decomposition and coordination method allowing the integrated simulation of the centralized power system and the active distribution network, an algorithm to solve the single-stage optimal power flow in the distribution system as well as two criticality criteria allowing to decrease the computational burden of the simulation when it is used for planning purposes

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Berglund, Simon. "Rock cavern as thermal energy storage." Thesis, Luleå tekniska universitet, Energivetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79596.

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In the fall of 2019, a comprehensive idea study was conducted on heat storage in two rock caverns located at Näsudden in Skelleftehamn and was part of the project course "Energiteknik, huvudkurs" at Luleå University of Technology. This idea study investigated the conditions of using waste heat from Boliden AB:s copper smeltery (Rönnskär) and storing this waste heat in two rock caverns and use them as seasonal thermal storage tanks, with the purpose of using the heat in the nearby district heating network, thus replacing some of the oil burned at Rönnskär. To investigate this, the authors of the idea study looked at two different storage cycles of seasonal storage and modeled this in ANSYS Fluent to simulate the heat storage and the heat losses. The results from this idea study showed promising results for using these caverns as heat storage and this work is therefore a continuation of the idea study. Since the study provided a good understanding of the conditions for seasonal storage, some questions arose about how the rock caverns will behave during an intermittent operation, which is the planned mode of operating the caverns in case of deployment. In this thesis, intermittent operation of these caverns are explored and how this effects the temperature in the caverns and its surrondings, the charge/discharge speed, how insulated walls affect the operation and how much oil is replaced. At the beginning of this project a review of the idea study and similar projects was done to gain deeper knowledge about the subject, but also to get a wider grasp on the different problems that could arise during the thesis. Relevant data for the caverns was collected and acquired to get a deeper understanding of its geometry, layout and what kind of modifications are really possible. Further data from the district heating networks of Boliden AB and Skellefteå Kraft was acquired. The available waste heat from Rönnskär was examined and used to calculate the chargeable energy by hour for the caverns, with the limits of Skelleftehamn district heating network in mind. By examining the different steam boiler patterns, the discharge pattern could be calculated. Using CFD, the unknown global heat transfer coefficient between the cavern water and the cavern wall can be determined. This data was then used with a set of differential equations to model the behavior of the caverns in Simulink. This allowed to determine the behavior for the caverns during normal operation, such as how the heat losses evolve, how the temperatures fluctuate, how much heat the caverns can be charged with and how much they can discharge. The results from the simulations showed that the caverns discharge a higher amount of energy when operating intermittently than when operating seasonally. Depending on how the caverns are utilized, different amounts of discharged energy are obtained. This range from 2224,7MWh to 7846,1MWh for the different discharging patterns. The usage also affects the efficiency of the cavern giving the efficiency a range between 19% to 53,9%. The heat losses range from around 20kW to 1000kW, depending on operation. Insulating the cavern walls reduces on average the heat losses by a factor of 5. Operating the caverns intermittently would on average remove a total of 29 ktonne CO2 and 88,74 tonne NOx for its expected lifespan of 30 years. Economically, the rock caverns have good economic potential as they would save about 80 million SEK during their lifetime just from buying less oil. Hösten 2019 genomfördes en omfattande idéstudie om värmelagring i två bergrum vid Näsudden i Skelleftehamn och var en del av projektkursen "\textit {Energiteknik, huvudkurs}" vid Luleå tekniska universitet. Denna idéstudie undersökte villkoren för att använda spillvärme från Boliden AB:s kopparsmältverk (Rönnskär) och lagra denna värme i bergrummen och använda dem som säsongslagrade ackumulatortankar. Syftet med detta var att använda värmen i det närliggande fjärrvärmenätverket och därmed ersätta en del av den förbrända oljan hos Rönnskär. Författarna utforskade detta genom att undersöka två olika lagringscykler för säsongslagring och modellerade detta i ANSYS Fluent för att simulera värmelagring och värmeförluster. Resultaten från idéstudien visade lovande resultat för säsongsbaserad värmelagring i dessa bergrum och detta arbete är därför en fortsättning av idéstudien. Eftersom studien gav en god förståelse för förhållandena för säsongslagring, uppstod några frågor om hur bergrummen kommer att bete sig under en intermittent drift, vilket är den planerade driften av bergrummen vid en framtida användning. I detta projekt undersöks intermittent drift av dessa bergrum och hur detta påverkar temperaturen i bergrummen och dess omgivning, laddnings- / urladdningshastigheten, hur isolerade väggar påverkar driften och hur oljeförbrukningen reduceras. I början av detta projekt gjordes en genomgång av idéstudien och liknande projekt för att få djupare kunskap om ämnet, men också för att få ett bredare grepp om de olika problem som kan uppstå under arbetets gång. Relevant data för bergrummen samlades in och anskaffades för att få en djupare förståelse för dess geometri, layout och vilken typ av ändringar som verkligen är möjliga. Ytterligare data från fjärrvärmenätverket för Boliden AB och Skellefteå Kraft förvärvades. Den tillgängliga spillvärme från Rönnskär undersöktes och användes för att beräkna den urladdningsbara energin per timme för bergrummen, med begränsningarna i Skelleftehamns fjärrvärmenät i åtanke. Genom att undersöka de olika ångpannmönstren kan urladdningsmönstret beräknas. Med hjälp av CFD kan den okända globala värmeöverföringskoefficienten mellan bergrumsvattnet och bergväggen bestämmas. Denna data användes sedan med en uppsättning differentialekvationer för att modellera driften av bergrummen i Simulink. Detta gjorde det möjligt att bestämma beteendet för bergrummen under normal drift, till exempel hur värmeförlusterna utvecklas, hur temperaturen fluktuerar, hur mycket värme bergrummen kan laddas med och hur mycket de kan ladda ur. Resultaten från simuleringarna visade att bergrummen kan ladda ur en större mängd energi än vid en säsongsbetonad drift. Beroende på hur grottorna utnyttjas erhålls olika mängder urladdad energi. Detta sträcker sig från 2224,7MWh till 7846,1MWh för de olika urladdningsmönstren. Användningen påverkar också grottans effektivitet vilket ger en effektivitet mellan 19% och 53,9%. Värmeförlusterna sträcker sig från cirka 1000 kW till 20kw, beroende på drift. Isolering av bergväggarna minskar i genomsnitt värmeförlusten med en faktor 5. Att använda grottorna intermittent skulle i genomsnitt ersätta totalt 29 kton CO2 och 88,74 ton NOx för den förväntade livslängden på 30 år. Bergrummen har även god ekonomisk potential eftersom de skulle spara cirka 80 miljoner SEK under sin livstid bara från minskade oljekostnader.

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8

Shankland, Neil J. "Development of an intermittent chemical/vapour-compression heat pump, using a sunspace as a heat source." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282643.

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9

Barton, John P. "A probabilistic method of modelling energy storage in electricity systems with intermittent renewable energy." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/9727.

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A novel probabilistic method has been developed for modelling the operation of energy storage in electricity systems with significant amounts of wind and solar powered generation. This method is based on a spectral analysis of the variations of wind speed and solar irradiance together with profiles of electrical demand. The method has been embodied in two Matlab computer programs: Wind power only: This program models wind power on any time scale from seconds to years, with limited modelling of demand profiles. This program is only capable of modelling stand-alone systems, or systems in which the electrical demand is replaced by a weak grid connection with limited export capacity. 24-hours: This program models wind power, solar PV power and electrical demand, including seasonal and diurnal effects of each. However, this program only models store cycle times (variations within a time scale) of 24 hours. This program is capable of modelling local electrical demand at the same time as a grid connection with import or export capacity and a backup generator. Each of these programs has been validated by comparing its results with those from a time step program, making four Matlab programs in total. All four programs calculate the power flows to and from the store, satisfied demand, unsatisfied demand and curtailed power. The programs also predict the fractions of time that the store spends full, empty, filling or emptying. The results obtained are promising. Probabilistic program results agree well with time step results over a wide range of input data and time scales. The probabilistic method needs further refinement, but can be used to perform initial modelling and feasibility studies for renewable energy systems. The probabilistic method has the advantage that the required input data is less, and the computer run time is reduced, compared to the time step method.

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10

Görtz, Steffen. "Battery energy storage for intermittent renewable electricity production : A review and demonstration of energy storage applications permitting higher penetration of renewables." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-104285.

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Driven by resource politics and climate change, the transition from conventional fossil fuel based and centralized energy generation to distributed renewables is increasing rapidly. Wind and solar power generation offer carbon dioxide neutral electricity but also present some integration difficulties for energy system operators and planners due to intermittent power output. A promising way of dealing with the intermittency from renewables is energy storage. The method of storing energy in the electricity grid, especially by the means of electrochemical storage, has gained a lot of attention over the last years in the energy sector. While most utilities and energy market stakeholders have the basic understanding of energy storage, a more profound knowledge of grid storage applications is often lacking. This thesis aims to highlight and explain possible energy storage applications with focus on renewables integration. Battery energy storage can allow higher amounts of renewable electricity generation to be integrated by smoothening power output, time shifting generated energy to follow demand and increase hosting capacities through peak shaving. Power quality related issues due to intermittency can be mitigated by controlling the storage’s charging patterns to respond to grid variables. For optimal utilization and maximum storage value, several applications should be within the operational repertoire of the storage unit. Other applications including arbitrage, grid investment deferral and load following are discussed. Several battery technologies which have been developed and tested for such applications including lead acid, sodium sulfate and lithium-ion are presented. The most promising battery energy storage technology is lithium-ion with exceptional storage characteristics and most importantly a favorable near term price development. Two case studies on two of Umeå Energy’s low voltage networks simulating high penetrations of solar generation have been carried out to demonstrate mitigation of overvoltage and peak shaving with battery energy storage systems. The simulations show that energy storage systems can successfully be used to aid the integration of renewables in the electricity grid. Present capital costs are still too high for energy storage to be feasible but falling pricing and a developing market is foreseen to lower the hurdles. The main obstacle for energy storage at grid scale besides high capital costs are, in principle, non-existing legal frameworks regulating the ownership of energy storage systems and system technology standardization. Further discussions on the matter in combination with testing and pilot projects are needed to gain national and international experience with battery energy storage for the successful high share integration of renewables. Sinande naturresurser och växthuseffekten driver på övergången från centraliserad kraftproduktion baserad på fossila bränslen till distribuerad förnyelsebar energiproduktion i rask takt. Vind- och solkraft levererar koldioxidneutral el men ställer samtidigt balansansvariga och elnätsplanerare inför en rad problem på grund av periodiskt återkommande och tidvis ostabil effektgenerering. Energilager presenteras som en lovande lösning på problemen orsakade av förnyelsebara energikällor Att lagra energi i elnätet, i synnerhet med batterier, har fått en hel del uppmärksamhet de senaste åren i energibranschen. De flesta elnätsbolag och intressenter på energimarknaden har en grundläggande förståelse kring energilagring i elnätet men saknar ofta mer djupgående kunskap. Detta examensarbete syftar att belysa och förklara användningsområden och potentialer för energilagring med fokus på integreringen av förnyelsebara energikällor. Teorin beskriver hur batterilager kan användas för tillåta integreringen av en hög andel förnyelsebar elproduktion. Några tillämpningar är; effektutjämning, lagring av producerad energi för senare bruk samt ökad nätkapacitet genom att kapa toppar. Problem relaterade till försämrad elkvalité orsakad av varierande kraftproduktion visas kunna pareras med hjälp av programmerbara energilagringssystem som läser av storheter på elnätet såsom spänning och frekvens. För att utnyttja energilagret optimalt och komma åt dess maximala värde bör flera användningsområden kombineras. Därför diskuteras även andra användningsområden såsom arbitrage, lagringskapacitet för att skjuta upp eller undvika förstärkning av elnätet och lastföljning. Ett flertal batteriteknologier aktuella för de diskuterade användningsområdena såsom bly-, natriumsulfat- och litium-jonbatterier presenteras. Den mest lovande teknologin är litium-jon tack vare dess utmärkta egenskaper och framförallt mycket gynnsamma förväntade prisutveckling. Två fallstudier av två av Umeå Energi´s nätområden med hög simulerad andel solenergiproduktion har utförts för att demonstrera utnyttjandet av energilager för reglering av överspänning och kapning av toppar. Simuleringarna visar att energilagringssystem med framgång kan underlätta integreringen av förnyelsebara energikällor. Dagens kapitalkostnader är fortfarande för höga för att energilagring ska vara ekonomiskt försvarbart men fallande priser och en växande marknad väntas verka till teknikens fördel. Det visar sig att regelverk gällande ägandeskapet och standardiseringen av energilager är i det närmaste obefintliga vilket utgör ytterligare hinder för tekniken. Fortsatta diskussioner gällande dessa punkter i kombinationen med test- och pilotanläggningar för att införskaffa erfarenhet av energilagring i elnätet krävs.

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Torras, Ortiz Santiago. "Numerical simulation of sensible and latent thermal energy storage systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/392616.

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El objetivo principal de esta tesis es la resolución numérica de problemas de transferencia de calor y dinámica de fluidos y su aplicación para el estudio del comportamiento transitorio de sistemas térmicos de acumulación de energía (TES). Tres diferentes sistemas han sido considerados, cubriendo un amplio rango de condiciones de trabajo (desde muy baja de temperatura criogenica hasta muy alta temperatura en plantas CSP) y aplicaciones (desde domestica/residencial hasta energía renovables o de la industria aeroespacial). En este sentido, i) sistemas recuperadores de energía térmica para residencias en el rango de bajo a media temperatura; ii) un acumulador térmico usado un sistema de propulsión criogenica en el espacio en el rango de baja temperatura y; iii) sistema de acumulación térmica del tipo dos tanque para plantas solares de alta concentración en el rango de alta temperatura. La tesis esta dividida en cinco capítulos. El capitulo 2, esta dedicado en presentar la metodología empleada para la resolución computacional de la dinámica de fluidos y problemas de transferencia de calor en un dispositivo con almacenamiento para la recuperación de energía térmica de agua que se vierte al drenaje para viviendas residenciales. El estudio de las características del dispositivo fue realizado usando herramientas numéricas y experimentales. La simulación numérica fue realizada usando la plataforma NEST. La discretización de la ecuaciones de gobierno basadas en técnicas de volúmenes finitos. Correlaciones empíricas especiales han sido implementadas para ser usadas en la resolución numérica del flujo de fluido dentro de una tubería en espiral. Una infraestructura experimental ha sido desarrollada para el análisis del sistema. Diferentes flujos másicos y temperaturas de operación han sido estudiados. Los resultados numéricos han sidos comparados con resultados experimentales. La simulación numéricas realizadas predicen razonablemente bien el comportamiento transitorio de estos dispositivos. El capitulo 3, enfoca su atención en un prototipo de acumulador para baja temperatura usado para sistemas de propulsión criogenica en el espacio. Las simulaciones numéricas fueron realizadas usando la plataforma NEST. En este capitulo, dos modelos numéricos son adaptados, uno para resolver el flujo bifásico a través de tuberías bajo condiciones criogenicas, y otra para solucionar el material de cambio de fase usando un modelo entalpico de malla fija. El análisis numérico se basa en: i) la resolución unidimensional y transitoria de las ecuaciones gobernantes del fluido propulsor; ii) resolución multidimensional y transitoria de las ecuaciones gobernantes en la región ocupada por el material de cambio de fase, incorporando modelo de turbulencia para solucionar el fenómeno de convección que se produce; iii) los elementos solidos son modelados considerando un tratamiento multidimensional y transitorio de la ecuación de la energía. Los resultados numéricos son comparados con resultados experimentales de la literatura. La validación experimental bajo diferentes condiciones de trabajo de fluido criogenico y/o del material de cambio de fase muestra las posibilidades de este modelo para fines de optimización del diseño y de predicción. El capitulo 4, esta enfocado en el desarrollo de modelos numéricos para la simulación de sistemas de acumulación de energía térmica de dos tanques en centrales solares de alta concentración. La simulación numérica fue desarrollada dentro de la plataforma NEST, donde los diferentes elementos que componen el sistema son asociados para solucionar todo el sistema. Algunos elementos del sistema han sido especialmente desarrollados. Los modelos matemáticos consideran el comportamiento transitorio de la sal fundida, el gas de la cavidad, las paredes del tanque y sus aislantes, diferentes configuraciones de cimientos, la radiación entre la sal y las paredes del tanque en la zona de la cavidad del gas The main objective of this thesis is the numerical resolution of heat transfer and fluid flow problems and its application to study the unsteady behaviour of thermal energy storage (TES) systems. Three different systems have been considered, covering a wide range of working conditions (from very low cryogenic temperature to very high temperature CSP plant) and applications (from domestic/residential to renewable or aerospace industry). In that sense, i) for residential heat recovery systems in the low-to-medium temperature range; ii) a thermal accumulator used in a in-space cryogenic propulsion system in the low temperature range and; iii) the two-tank thermal energy storage system in concentrating solar power (CSP) plants in the high temperature range. The thesis is divided into five chapters. Chapter 2 is devoted to present the methodology employed for the resolution of Computational Fluid Dynamics (CFD) and Heat Transfer problems in a drain water heat recovery (DWHR) storage-type unit for residential housing. The study of the performance of this device has been carried out using both numerical and experimental tools. The numerical simulation has been performed using the NEST platform, where the different elements of the DWHR storage are linked to solve the system. The discretisation of the governing equations based on finite volume techniques (FVM) is presented. Numerical techniques such as the discretisation schemes, boundary conditions implementation and solution procedure for incompressible and transient flow problems are shown. Special empirical correlations have been implemented to be used in the numerical resolution of the single-phase flow inside the coiled pipe. An experimental infrastructure has been developed to analyse the whole system. Different internal flow rates and operational temperatures have been studied. The numerical results are compared against experimental results. The numerical simulations performed predict reasonably the transient behaviour of the DWHR storage device. Chapter 3 focuses the attention on a Low Temperature Accumulator prototype used in an in-space cryogenic propulsion system. The numerical simulation has been carried out using the NEST platform, where the different elements of the thermal accumulator are linked to solve the whole system. In this chapter, two numerical models have been adapted, one used to solve the two-phase flow inside ducts working under cryogenic conditions, and another to solve the PCM using a fixed-grid enthalpy model. The numerical analysis is based on: i) a one-dimensional and transient resolution of the governing equations for the fluid flow of propellant; ii) a multi-dimensional and transient resolution of the governing equations in the region occupied by the PCM, incorporating a model for the turbulence to solve the convection phenomena involved; iii) the solid elements are modelled considering a multidimensional and transient treatment of the thermal conduction equation. The numerical results are compared against experimental results from the literature. The experimental validation under different working conditions of the cryogenic flow and/or the PCM material shows the possibilities of this model for design optimization and prediction purposes. Chapter 4 is focused on the development of a numerical model for the simulation of the two-tank thermal energy storage system in concentrating solar power (CSP) plants. The numerical simulation has been performed using the NEST platform, where the different elements of the two-tank storage are linked to solve the system. Some elements of the system have been specifically developed. The mathematical model considers the transient behaviour of the molten salt fluid, the gas ullage, the tank walls and insulation, different configuration of the foundation, radiation exchange between the salt and the tank walls in the ullage. A parametric study of the two-tank storage system has been done, in order to identify

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12

Granado, Pedro Crespo del. "The value of energy storage from intermittent renewables : an end user perspectives in Smart Grids." Thesis, Lancaster University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.732707.

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The widespread deployment of renewable energy in combination with smart grid technologies is creating the opportunity for energy storage to play a critical role in energy systems and be a more prevalent technology in the near future. This research adopts a bottom-up approach to model the interactions within the energy system, namely between renewable supply and storage technologies at the end-user level (e.g. in houses, buildings and communities). That is, the papers presented in this thesis investigate the value of energy storage in smart grids from an end-user perspective. Specifically, it focuses on the role of storage units in the regulation of the energy system’s supply-demand balance and the cost savings for the end-user. Hence, the contribution of this study lies in the perspective taken (end-user), as well as in the models developed for the valuation of energy storage. In this sense, it provides an understanding of different aspects associated with the valuation of storage technologies in smart grids. Particular attention is paid to the contribution of local wind energy supply as well as demand response (smart grids). Analytics data-driven optimization is central in this research. To analyze the interactions on complementing energy storage with decentralized energy system in smart grids, this thesis develops models for two real-life case studies: The first paper assess the value of batteries in domestic houses in sync with on-site renewable micro generation. A second paper extends the research, bottom-up, to a community dependent on its own hybrid decentralized generation coupled with energy storage units. As uncertainty of wind generation is not considered in these cases, a third paper investigates the storage valuation by a stochastic programming approach.

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13

Vacs, Renwick Deborah Alexandra. "The effects of an intermittent piped water network and storage practices on household water quality in Tamale, Ghana." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82721.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 67-69). The United Nations Millennium Development Goals include a target to halve the number of people without access to "improved" water sources, which include piped water supply. However, an "improved" source of water does not necessarily indicate a safe source. The city of Tamale in northern Ghana has a piped water network that supplies treated water, but the system is intermittent and many users only have access to piped water several days per week. In order to have sufficient supply of water, users are forced to store large quantities of water in their homes, sometimes in unsanitary storage containers. Samples taken from households around Tamale indicate that there is widespread contamination of drinking water as indicated by total coliform, E. coli, and lack of chlorine residual. Examination of data from Ghana Water Company Limited, the local utility shows that water quality is being degraded between the treatment plant outlet and use by households. This degradation could be caused by low-pressure situations in the intermittent distribution system, allowing contaminants to enter the system. The contamination could also be caused by unhygienic water storage practices in the home, such as storing water in open containers and dipping unwashed hands into the water supply. Interviews conducted in 40 households show that many households do not practice hygienic water storage and handling. In the short term, it is recommended that local NGOs or local government agencies increase efforts to educate users about proper water handling and storage practices to decrease bacteriological contamination of drinking water in the home. In the long-term, it is recommended that the intermittency of the system be decreased by improving maintenance on pipelines and removing illegal connections. by Deborah Alexandra Vacs Renwick. M.Eng.

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14

Proser, Noah. "Energy Storage: Technology for a More Efficient Grid." Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/cmc_theses/264.

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Energy storage technologies have the potential to revolutionize the electric grid by allowing for the integration of renewable generation while increasing the utilization and efficiency of current grid assets. These technologies include pumped hydroelectric storage, compressed air energy storage (CAES), flywheels, batteries, thermal energy storage (TES), super capacitors, and superconducting magnetic energy storage (SMES). While energy storage has been implemented in some areas, its benefits are greatly undervalued by current regulatory frameworks leading to suboptimal outcomes for grid operators, utilities, and ratepayers. Large-scale adoption of storage technologies will require regulatory frameworks that recognize the benefits of grid-scale storage across generation, and transmission and distribution. This thesis discusses the need for storage, currently available and developing storage technologies, and the present regulatory environment.

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15

Barbour, Edward. "Investigation into the potential of energy storage to tackle intermittency in renewable energy generation." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8189.

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Renewable Energy is by nature intermittent and matching the supply of energy to specific time dependent demand poses huge challenges. Energy storage is a useful tool in handling this temporal disparity, although except for regions very suitable for pumped hydroelectric storage schemes, it suffers from being technically difficult to implement and costly as a result. This study investigates the potential benefits offered by various scales of energy storage to different types of renewable energy generation. It also explores the economic drivers behind energy storage operating as part of an electricity spot market. A stochastic optimisation algorithm for determining the maximum possible arbitrage revenue available to energy storage devices is presented and schedule of operation of storage acting in this manner is analysed. The schedule of operation for maximising the revenue is compared to the schedule of operation for minimising the fuel cost to the network and it is demonstrated that because prices are more volatile than the demand which drives them, storage devices do not always act to decrease the fuel cost to the network. It is shown that storage behaving in the right manner can offer significant benefits to electricity systems, and increases the usage of base-load generation, reducing peak electricity demands and the need for expensive peaking plants. The value of storage also increases as the penetration of renewable energy generation increases, although the current electricity market framework is perhaps not the best way to encourage this behaviour. Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) is also identified as a theoretical storage option which deserves further scrutiny. Using thermodynamic modelling the efficiency of this type of system is estimated in the range of 63-67%, and we suggest that this may be increased closer to 73% by using direct contact heat exchangers rather than indirect contact heat exchangers (and a separate thermal fluid), as described in the currently available literature. However, dealing with large pressure ranges (leading to large variations in pressure ratios) encountered in the expansion process is a problematic area which will have to be resolved before this type of system can be constructed with “off-the-shelf” components. Some small scale experiments are used to gain valuable insights into a AA-CAES system. While these suffer from a very low overall efficiency, they highlight the effect of variable pressure ratio on expander efficiency. We conclude that AA-CAES is thermodynamically sound and will be achieved one of two ways: either through the construction of expanders that can work with high efficiency over large pressure ratios, or by resolving the engineering issues with maintaining a constant storage pressure.

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Salevid, Karin. "Market Requirements for Pumped Storage Profitability : Expected Costs and Modelled Price Arbitrage Revenues, Including a Case Study of Juktan." Thesis, Uppsala universitet, Elektricitetslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-210136.

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The rapid integration of intermittent renewable energy sources (IRES) has caused a growing demand for power system flexibility on energy markets all over Europe. Being the only commercially proven large scale energy storage technology, pumped storage hydro power (PSHP) has by several studies been suggested as an efficient solution to mitigate the impact of IRES. However, despite the perceived technical demand profitability remains as a major obstacle for PSHP development. In this study, a market requirement for PSHP profitability, defined in terms of price volatility, is presented. Considering capital and operational expenditures as well as modelled potential price arbitrage revenues for a greenfield PSHP plant, it may be used as a tool for initial assessments of PSHP profitability in relation to market outlooks or modelled future prices. The results have further been used in a case study, where the price volatility required to motivate a restoration of the now decommissioned Swedish PSHP plant Juktan has been determined. The results show that the high capital expenditures characterising PSHP development do comprise in a high risk for developers; while feasibility depends on the sustainment of a highly volatile price climate during several decades, energy markets are often extremely uncertain.

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17

Gustafsson, Amelie, and Hannes Wiklund. "Batterier i kraftsystemet : En studie i batteriers potential som energilagring för stöd av intermittenta energikällor i det nationella kraftsystemet." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255867.

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Utveckling av det moderna samhället och den fortsatt accelererande energiintensiva tillvaro människan lever i sätter stor press på klimatet. För att nå de hållbarhetsmål FN satt upp som bland annat innebär minskade utsläpp och effektivare energianvändning krävs krafttag i det globala energisystemet. För att öka andelen modern och ren energi krävs att sol- och vindkraft prioriteras. Ett stort problem med dessa energikällor är dess intermittenta produktion vilken alstrar oregelbunden elektricitet och ställer nya krav på elnätet. För att underlätta implementering av förnybara energikällor på det nationella elnätet och i mindre energisystem undersöks i den här rapporten de förutsättningar som finns för att integrera batterienergilagringssystem i kombination med intermittenta energikällor. Rådande förutsättningar redogörs för i en omfattande litteraturundersökning där bland annat elnätets funktion, lovande batteriteknologier, ekonomiska incitament för batterienergilagring och framtidspotential undersöks. Ett globalt engagemang för att öka andelen förnybar energi med hjälp av batterienergilagring i det globala energisystemet identifieras. Vidare visas batterienergilagringssystem har stor potential att minimera den belastning intermittenta energikällor har på elnätet. Potentialen begränsas i nuläget av rådande politiska styrmedel och elmarknadens utformning då en småskalig elproducent idag gynnas av att direkt mata ut överskottsel på elnätet istället för att använda energilagring. Med en växande andel intermittent elproduktion förväntas minskade begränsningar och batterienergilagring kopplat till elproduktion bli mer lönsamt. The development of the modern society and the global continuously accelerating energy intensive way of living is putting stress on the climate. In order to achieve the UNs set of sustainability goals, including reduced emissions and more efficient use of energy, vigorous actions in the global energy system is required. To increase the share of clean and modern energy generation a larger quantity of solar and wind power is required. Due to weather dependency these resources generate intermittent electricity which will put new challenges on the grid. To facilitate the implementation of intermittent energy sources on the national grid and in smaller energy systems this report aims to investigate current prerequisites on integrating battery energy storage systems and intermittent resources to increase the share of clean energy sources in the power system. Current prerequisites are presented as the result of an extensive literature study where the electrical grid, promising battery technologies, financial incentives for battery energy storage and future potential is examined. A global commitment to increase the share of renewable energy sources using battery energy storage system in the global energy system is identified. Furthermore, battery energy storage systems are shown to have great potential in limiting the negative impact of intermittent energy sources on the electrical grid. This potential is currently being limited by existing political control means and the design of the electricity market such that small producers are benefitted by directly supplying the grid with excess electricity instead of using energy storage. With a growing share of intermittent power generation these limitations are expected to ease and battery energy storage systems in connection with power production becoming more profitable.

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18

Villavicencio, Manuel. "Analyzing the optimal development of electricity storage in electricity markets with high variable renewable energy shares." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLED044/document.

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L’essor des technologies renouvelable à apport variable pose des nombreuses difficultés dans le fonctionnement du système électrique. Ce système doit garantir l’équilibre offre-demande à tout moment, ainsi que d’assurer des hauts niveaux de fiabilité du service. Donc, la variabilité accroît les besoins de flexibilité et des services système. Ils existent plusieurs options capables de fournir ceux services, dont : le renforcement des interconnections, le pilotage intelligent de la demande, le renforcement des capacités de réponse rapide des unités de production, mais aussi, le mis en œuvre des technologies de stockage de l’électricité. Cependant, les marchés électriques actuels sont basés sur la rémunération de l’énergie. Donc, la valorisation intégrale des services qui peut fournir le stockage semble difficile, ce qui restreint le « business case » des options de flexibilité.Cette thèse s’inscrit autour des propos suivants : (1) modéliser et évaluer les interrelations entre variabilité, besoins de flexibilité et objectifs de décarbonation du parc électrique, (2) analyser le rôle, ainsi que la valeur, des différents technologies du stockage à travers le cas Français aux horizons 2020, 2030 et 2050, et (3) discuter sur les aspects de régulation de la flexibilité, ainsi que proposer des politique énergétiques concrètes permettant la réussite des objectifs de transition énergétique et de décarbonation du mix électrique français The increasing variability of electricity production in Europe, which is mainly due to the intermittent production of renewables such as wind and photovoltaic (VRE), will require significant efforts to reconcile demand and supply at all times. Thus, increasing shares of variability imply increasing amounts of system services. In addition to upgraded interconnections, demand-side management (DSM) and dispatchable backup capacity, electric energy storage (EES) technologies will have a major role to play in this context.However, due to the peculiar price formation mechanism prevailing in energy-only electricity markets, the commercial case for EES is being eroded by the very forces that create the need for its increased deployment at the system level. The private incentives of EES are thus diminishing while its social value, which is determined by the multiple system services these technologies can supply, is increasing.This thesis sets out to (1) model and assess the interplays between variability, flexibility needs and decarbonization objectives, (2) analyze the role and the value of EES technologies in view of the French official objectives by 2020, 2030 and 2050, and (3) discuss regulatory aspects, and propose a set of energy policies allowing to succeed in the energy transition and decarbonization goals

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Alhaider, Mohemmed Masooud. "Optimal Demand Response Models with Energy Storage Systems in Smart Grids." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6451.

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This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management. The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to be installed in a power system. This model also aims to design optimal switchable loads programs for a community. The penetration of the switchable loads versus the size of the BESS is investigated. Another model is developed to design an optimal load operation scheduling of a residential heating ventilation and air-conditioning system (HVACs). This model investigates the ability of HVACs to provide optimal demand response. The model also proposes a comfort/cost trade-os formulation for end users. A third model is proposed to incorporate the uncertainty of the photovoltaic power in a residential model. The model would nd the optimal utilization of the PV-output to supply the residential loads. In the first part of this research, mixed integer programming (MIP) formulations are proposed to obtain the optimal capacity of the (BESS) in a power system. Two optimization problems are investigated: (i) When the BESS is owned by a utility, the operation cost of generators and cost of battery will be minimized. Generator on/o states, dispatch level and battery power dispatch level will be determined for a 24-hour period. (ii) When the BESS is owned by a community for peak shaving, the objective function will have a penalty component for the deviation of the importing power from the scheduled power. MIP problems are formulated and solved by CPLEX.The simulation results present the effect of switchable load penetration level on battery sizing parameters. In the second part, a mixed integer programming (MIP) based operation is proposed in this part for residential HVACs. The objective is to minimize the total cost of the HVAC energy consumption under varying electricity prices. A simplied model of a space cooling system considering thermal dynamics is adopted. The optimization problems consider 24-hour operation of HVAC. Comfort/cost trade-o is modeled by introducing a binary variable. The big-M technique is adopted to obtain linear constraints while considering this binary variable. The MIP problems are solved by CPLEX. Simulation results demonstrate the effectiveness of HVAC's ability to respond to varying electricity price. Then, in the final part of this research, two Benders Decomposition strategies are applied to solve a stochastic mixed integer programming (MIP) formulation to obtain the optimal sizing of a photovoltaic system (PV) and battery energy storage system (BESS) to power a residential HVACs. The uncertainty of PV output is modeled using stochastic scenarios with the probability of their occurrence. Total cost including HVAC energy consumption cost and PV/battery installation cost is to be minimized with the system at grid-connected mode over eight hours subject to a varying electricity price. The optimization problem will nd the optimal battery energy capacity, power limit, a number of PV to be installed, and expected HVAC on/o states and BESS charging/discharging states for the next eight hours. This optimization problem is a large-scale MIP problem with expensive computing cost.

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Estaña, Garcia Guillermo, and Julian Iñigo Ruiz. "Feasibility of converting a Science Park in a cold climate into an “off-grid” facility using renewable energies and seasonal storage systems." Thesis, Högskolan i Gävle, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-30417.

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The collateral effects of fossil fuels push humanity to seek solutions to these adversities. Energy efficiency and renewable energies have gone from being almost imaginary concepts to necessary. Several studies have shown that self-sufficiency through photovoltaic systems and wind energy is possible. In addition, it is necessary a storage of the surpluses of both since it increases notably the efficiency of these systems and supposes to the short/medium term a saving of money in the consumer. Due to the mentioned before, the aim of the thesis is to convert a science park located in a cold climate such as Sweden into a complex that does not depend energetically on external sources. For this purpose, a series of data from the park were first collected and then simulated and optimised using the HOMER software for different energy configurations. At the same time, a computer code was created in MatLab to enable the energy produced to be used responsibly. The proposed system consists of PV panels, wind turbines and a battery. Thanks to it, a 64 % renewable fraction is achieved, which means a reduction of 27.45 tons of CO2 per year. In addition, through the energy management system created, the electricity contract is reduced, reducing the purchase of electricity during peak hours. It is concluded that the implementation of both proposed systems contributes significantly to the achievement of the sustainable goals set for 2 030 by the main world leaders, even though a total disconnection with the electrical grid has not been achieved.

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21

Anderson, Matthew John. "Economic and Environmental Analysis of Cool Thermal Energy Storage as an Alternative to Batteries for the Integration of Intermittent Renewable Energy Sources." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51195.

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The balance of the supply of renewable energy sources with electricity demand will become increasingly difficult with further penetration of renewable energy sources. Traditionally, large stationary batteries have been used to store renewable energy in excess of electricity demand and dispatch the stored energy to meet future electricity demand. Cool thermal energy storage is a feasible renewable energy balancing solution that has economic and environmental advantages over utility scale stationary lead-acid batteries. Two technologies, ice harvesters and internal-melt ice-on-coil cool thermal energy storage, have the capability to store excess renewable energy and use the energy to displace electricity used for building cooling systems. When implemented by a utility, cool thermal energy storage can replace large utility scale batteries for renewable energy balancing in utility regions with high renewable energy penetration. The California Independent System Operator (CAISO) region and the Electric Reliability Council of Texas (ERCOT) are utility regions with large solar and wind resources, respectively, that can benefit from installation of cool thermal energy storage systems for renewable energy balancing. With proper scheduling of energy dispatched from cool thermal energy storage, these technologies can be effective in displacing peak power capacity for the region, in displacing traditional building cooling equipment, and in recovering renewable energy that would otherwise be curtailed. Master of Science

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22

Ahmed, Samar. "Carbon neutral scenarios for Växjö municipality." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-104962.

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Sweden’s municipalities are leading the green energy transition, in this study, a techno-economic evaluation was done for a number of carbon neutral scenarios for Växjö municipality’s future energy system, situated within Sweden’s projected energy demand development in 2030 and 2050. The municipality’s partially decentralized energy system relies heavily on interconnected electricity supply from the national grid, and fuels imports from other parts of Sweden. It was a matter of question: in which ways will future demand changes induce supply changes, and whether a future carbon neutral energy system will be less costly in a sustained-electricity supply condition? To answer this, a balanced energy reference system for the municipality was created from an actual energy balance, using an hour-by-hour dynamic energy analysis tool EnergyPlan. Afterward, a future energy demand projection for Växjö was stemmed from the Swedish Energy Agency (SEA) sustainable future scenarios for Sweden, based on an average inhabitant energy demand. Modelling results for Växjö carbon neutral scenarios showed that Växjö energy system will be sufficient to supply future heat demand but not electricity demand, nor transport and industrial fuels. While in the short-term being carbon neutral is more economically attainable without changes in electricity supply technologies, a projected electricity price and consumption increase, change the outcomes for a carbon neutral scenario based on Intermittent Renewable Energy (IRE) to be less costly in the long term.

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Johansson, Jim. "Utilizing Energy Storage Applied on Floating Wind Turbine Economics Using a Spot-Price Based Algorithm." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-328934.

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In this paper, a new algorithm for utilizing energy storage is proposed and applied on floating wind turbine economics. The proposed algorithm’s decision making on storing energy or selling electricity onto the grid is based on the electricity price, which makes it unique and different from similar algorithms. From the literature review, it was concluded Ocean Renewable Energy Storage to be most suitable with the Spar-Type and Semi-Submersible floating wind turbine to which the paper is based upon. The objective of this paper is to find the suitable ratio of energy storage versus wind farm, find the product of increase in wholesale, and evaluate whether the proposed method makes the hybrid economically sound. The algorithm was applied on spot-price data from Denmark due to its large share of wind energy with wind data from off the coast of Morro Bay in California, USA. Additionally, a sensitivity analysis is applied to evaluate to energy storage cost impact as well as evaluate the algorithm by lowering the required energy storage size. Using the algorithm, the wind farm must account for nine days’ worth of energy production with a product of energy storage versus wind farm ratio of 1.42. The wholesale price increased with 11.9-21.5% for the four years studied, however, all financial results favored not utilizing energy storage. By the results derived from the sensitivity analysis, it was concluded that with future cost reductions, the algorithm will still favor no energy storage. However, by fine tuning the algorithm to reduce the need for storage, positive financial result might be achievable. The key to achieve a profitable result seems to rely on minimizing the need for energy storage, to which the proposed algorithm fail to achieve. Conclusively, spot-price decision-based energy storing is not economically sound.

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24

Torres, Escalona Javier. "Electronic properties study on hydrazines and nitriles complexed by Lewis acids. Towards chemical hydrogen storage." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3051.

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Dans la problématique de l'utilisation de nouvelles énergies non polluantes, l'hydrogène est l'un des principaux carburants verts du futur. Les dérivés d'hydrazine et de borane sont potentiellement intéressants pour le stockage chimique de l'hydrogène. Les complexes entre hydrazines ou nitriles avec des boranes ou des alanes sont à la base de cette étude. Ces composés ont été synthétisés afin d'étudier leur structure électronique avant et après la création de la liaison entre les acides et les bases de Lewis. La spectroscopie photoélectronique à rayonnement UV (UV-SPE) est utilisée comme outil principal de caractérisation fournissant des énergies d'ionisation (IE). L’interprétation des résultats expérimentaux est supportée par des calculs quantiques comme ΔSCF + TD-DFT, OVGF, P3 et SAC-CI. Des simulations et des expériences par Flash Vacuum Thermolysis (FVT) ont été effectuées, portant sur l’élimination d'hydrogène à partir de dérivés d'hydrazine borane Within the problematic of the use of new non-polluting energies, hydrogen is one of the main green fuels of the future. Hydrazine borane derivatives are potentially interesting chemical hydrogen storage materials. Complexes between hydrazines or nitriles with boranes or alanes are the basis of this study. These compounds were synthesized in order to study their electronic structure before and after creation of the bond between the Lewis acids and bases. Ultraviolet Photoelectron Spectroscopy (UV-PES) is used as a main characterization tool, providing Ionization Energies (IE). The interpretation of the experimental results is supported by Quantum Chemical Calculations as ΔSCF+TD-DFT, OVGF, P3 and SAC-CI methods. Simulations and experiments by Flash Vacuum Thermolysis (FVT) were carried out on hydrogen release from hydrazine borane derivatives

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Labidi, Mouchira. "Optimisation de chaufferies collectives multi-energies : dimensionnement et commande de systèmes de stockage thermique par hydro-accumulation." Thesis, Perpignan, 2015. http://www.theses.fr/2015PERP0007.

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Les travaux présentés dans ce manuscrit portent sur l’optimisation d’une chaufferie collective multi-énergie en l’équipant d’un système de stockage thermique de type hydro-accumulation. L’efficacité de ce dernier dépend de sa capacité à conserver son énergie initiale. Ainsi, pour minimiser les pertes thermiques, le système de stockage doit être correctement isolé. Un modèle de ballon d’hydro-accumulation stratifié est développé et validé expérimentalement. Une étude paramétrique est menée afin d’étudier l’impact, sur les pertes thermiques, de paramètres géométriques et météorologiques. Ensuite, une approche de dimensionnement, fondée sur une stratégie de gestion séquentielle et une étude paramétrique est proposée. Plusieurs critères énergétiques et économiques peuvent ainsi être évalués pour différents volumes de stockage thermique. L’approche de dimensionnement proposée a été appliquée à plusieurs sites exploités par Cofely GDF-Suez, notre partenaire industriel. Les résultats obtenus montrent que le dimensionnement optimal du système de stockage et la gestion intelligente du procédé permettent d'optimiser le fonctionnement d’un site. Des économies énergétiques et financières importantes peuvent ainsi être réalisées. La stratégie de gestion séquentielle proposée n’anticipe pas les besoins du réseau de chaleur. C’est pourquoi une stratégie fondée sur la commande prédictive (MPC pour Model Predictive Control) est susceptible d’améliorer le fonctionnement et les performances d’une chaufferie collective équipée d’un système d’hydro-accumulation. Afin de mettre en œuvre un tel contrôleur, la puissance thermique demandée par le réseau de chaleur doit être correctement prédite. Par conséquent, une méthode de prédiction a été développée. Elle s’appuie sur une analyse multi-résolution par transformée en ondelettes discrète et sur l’utilisation de réseaux de neurones artificiels de type perceptron multicouche. La stratégie séquentielle (non prédictive) et la stratégie prédictive ont été appliquées à une chaufferie collective mixte située dans une commune du nord de la France. Pour ce cas d’étude, la stratégie prédictive est plus efficace. De plus, les résultats montrent que, quelle que soit la stratégie utilisée, équiper la chaufferie d’un système d’hydro-accumulation correctement dimensionné est un investissement rentable. Il permet de minimiser la consommation d’énergie fossile et, par conséquent, le coût économique et les émissions de CO2 The present work deals with optimizing a multi-energy district boiler by adding to the plant a thermal water storage tank. The effectiveness of such a system depends on how long the stored energy can be kept without considerable degradation. The storage tank should be properly insulated to reduce the rate of heat loss. Thus, firstly, a stratified water thermal storage model is developed and experimentally validated. A parametric study is carried out to determine the influence of geometric and meteorological parameters on heat loss. Next, a reliable sizing method based on a sequential management strategy and a parametric study is proposed. Various energy and economic criteria have been evaluated for a range of thermal storage sizes. The proposed methodology has been applied to many plants managed by Cofely GDF-Suez, our industrial partner. Results highlight the ability of a thermal storage tank (optimally sized and managed) to improve the operation of a multi-energy district boiler and realize significant energy and economic savings. The main drawback of the proposed sequential management strategy lies in not taking into account the future power demand. That is why a strategy based on a Model Predictive Controller (MPC) is likely to improve operation and performance. In order to implement such a controller, the power demand has to be accurately forecasted. As a consequence, a short-term forecast method, based on wavelet-based Multi-Resolution Analysis (MRA) and multilayer Artiﬁcial Neural Networks (ANN) is proposed. Both the sequential and the predictive strategies are applied to a northeast France multi-energy district boiler selected as a case study. The main result to retain is that the efficiency of water thermal storage tank is mainly related to its design and the way it is managed. For this case study, the predictive strategy regardless the size of the storage tank, the predictive strategy is more reliable. Furthermore, in all cases an adequately sized and managed thermal storage tank is a profitable investment. It allows the fossil energy consumption to be signiﬁcantly reduced. The same remark applies to the functioning costs and CO2 emissions

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Tröndle, Tobias Wolfgang [Verfasser], and Ulrich [Akademischer Betreuer] Platt. "Development of a global electricity supply model and investigation of electricity supply by renewable energies with a focus on energy storage requirements for Europe / Tobias Wolfgang Tröndle ; Betreuer: Ulrich Platt." Heidelberg : Universitätsbibliothek Heidelberg, 2015. http://d-nb.info/1180395549/34.

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Anzalchi, Arash. "Advanced Solutions for Renewable Energy Integration into the Grid Addressing Intermittencies, Harmonics and Inertial Response." FIU Digital Commons, 2017. https://digitalcommons.fiu.edu/etd/3506.

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Numerous countries are trying to reach almost 100\% renewable penetration. Variable renewable energy (VRE), for instance wind and PV, will be the main provider of the future grid. The efforts to decrease the greenhouse gasses are promising on the current remarkable growth of grid connected photovoltaic (PV) capacity. This thesis provides an overview of the presented techniques, standards and grid interface of the PV systems in distribution and transmission level. This thesis reviews the most-adopted grid codes which required by system operators on large-scale grid connected Photovoltaic systems. The adopted topologies of the converters, the control methodologies for active - reactive power, maximum power point tracking (MPPT), as well as their arrangement in solar farms are studied. The unique L(LCL)2 filter is designed, developed and introduced in this thesis. This study will help researchers and industry users to establish their research based on connection requirements and compare between different existing technologies. Another, major aspect of the work is the development of Virtual Inertia Emulator (VIE) in the combination of hybrid energy storage system addressing major challenges with VRE implementations. Operation of a photovoltaic (PV) generating system under intermittent solar radiation is a challenging task. Furthermore, with high-penetration levels of photovoltaic energy sources being integrated into the current electric power grid, the performance of the conventional synchronous generators is being changed and grid inertial response is deteriorating. From an engineering standpoint, additional technical measures by the grid operators will be done to confirm the increasingly strict supply criteria in the new inverter dominated grid conditions. This dissertation proposes a combined virtual inertia emulator (VIE) and a hybrid battery-supercapacitor-based energy storage system . VIE provides a method which is based on power devices (like inverters), which makes a compatible weak grid for integration of renewable generators of electricity. This method makes the power inverters behave more similar to synchronous machines. Consequently, the synchronous machine properties, which have described the attributes of the grid up to now, will remain active, although after integration of renewable energies. Examples of some of these properties are grid and generator interactions in the function of a remote power dispatch, transients reactions, and the electrical outcomes of a rotating bulk mass. The hybrid energy storage system (HESS) is implemented to smooth the short-term power fluctuations and main reserve that allows renewable electricity generators such as PV to be considered very closely like regular rotating power generators. The objective of utilizing the HESS is to add/subtract power to/from the PV output in order to smooth out the high frequency fluctuations of the PV power, which may occur due to shadows of passing cloud on the PV panels. A control system designed and challenged by providing a solution to reduce short-term PV output variability, stabilizing the DC link voltage and avoiding short term shocks to the battery in terms of capacity and ramp rate capability. Not only could the suggested system overcome the slow response of battery system (including dynamics of battery, controller, and converter operation) by redirecting the power surges to the supercapacitor system, but also enhance the inertial response by emulating the kinetic inertia of synchronous generator.

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Edagi, Fernando Kazuhiro. "Pós-colheita de nêspera \'Fukuhara\': efeito de compostos salicilados, 1-metilciclopropeno e tratamentos térmicos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-09092009-103213/.

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O presente trabalho teve como objetivo desenvolver técnicas para o aumento da conservação de nêsperas cv. Fukuhara, evitando a perda de suculência, enrijecimento e escurecimento da polpa dos frutos. Para tal, aliou-se ao armazenamento refrigerado (1°C) a aplicação de compostos salicilados, 1-metilciclopropeno e tratamentos de condicionamento térmico. Em um primeiro experimento foi aplicado o ácido salicílico (AS) por imersão nas concentrações de 0, 1, 10 e 100mM e o salicilato de metila (MeSA) na forma gasosa a 0,05mM. No segundo experimento foi aplicado o 1- metilciclopropeno (1-MCP) a 0, 50, 500 e 5000nL L-1, além da aplicação de MeSA (0,01mM), associado ou não ao 1-MCP (500nL L-1). No terceiro experimento, os seguintes tratamentos foram aplicados: Controle: armazenamento a 1°C durante 60 dias; Padrão: armazenamento a 5°C durante 60 dias; Condicionamento térmico 1: armazenamento a 5°C durante 7 dias e 1°C durante 53 dias; Condicionamento térmico 2: armazenamento a 10°C durante 7 dias e 1°C durante 53 dias; Aquecimento intermitente: ciclos de 6 dias a 1°C + 1 dia a 15°C durante 60 dias; Aquecimento 1: condicionamento dos frutos a 37°C durante 3h e 1°C durante 60 dias; Aquecimento 2: condicionamento dos frutos a 37°C durante 6h e 1°C durante 60 dias. Nos três experimentos, os frutos foram armazenados durante 60 dias em bandejas de tereftalato de polietileno (PET) e embalados com filme de policloreto de vinila (PVC) com expessura de 14 µm. As determinações realizadas foram: firmeza de polpa, índice de escurecimento e podridão, acidez titulável, pH, teor de sólidos solúveis, teor de ácido ascórbico, teor de compostos fenólicos, atividade das enzimas fenilalanina amônia-liase (PAL), polifenoloxidase (PPO) e peroxidase (POD). As avaliações foram realizadas após 15, 30, 45 e 60 dias de armazenamento. A aplicação de 1mM de AS e 0,05mM de MeSA diminuíram a incidência de escurecimento interno enquanto concentrações superiores a 10mM de AS provocaram fitotoxidez nos frutos. Aplicação de 0,05mM de MeSA foi eficiente no controle de enrijecimento de polpa. A aplicação de 1-MCP foi eficiente no controle do escurecimento interno, enquanto que a aplicação de aquecimento intermitente e aquecimento a 37°C durante 3 horas foram eficientes no controle de escurecimento interno dos frutos. The aim of this work was to develop new techniques to improve the loquat fruit Fukuhara conservation, avoiding juiciness loss, increase in firmness and pulp internal browning. For this, allow to cold storage the application of salicilate compounds, 1- methylcyclopropene and temperature conditioning. In the first experiment four concentration of salicylic acid (SA) were applied: 0, 1, 10 and 100mM, and one concentration of methyl salicylate (MeSA) in gas: 0.05mM. In the second experiment four concentration of 1-MCP were applied: 0, 50, 500 and 5000nL L-1 in addition to 0,01mM of MeSA, associated or not to 500nL L-1 of 1-MCP. In the third experiment the treatment applied were: Control: storage at 1°C for 60 days; Standard: storage at 5°C for 60 days; Temperature conditioning 1: storage at 5°C for 7 days and 1°C for 53 days; Temperature conditioning 2: storage at 10°C for 7 days and 1°C for 53 days; Intermittent warming: cycles of 6 days at 1°C + 1 day at 15°C for 60 days; Heat treatment 1: fruit conditioning at 37°C for 3h + 1°C for 60 days; Heat treatment 2: fruit conditioning at 37°C for 6h + 1°C for 60 days. In the three trials, the fruits were packed in polyethylene tereftalate (PET) with PVC plastic film (14 µm thick). The parameters analyzed was: pulp firmness, decay and internal browning incidence, titratable acidity, pH, soluble solids content, ascorbic acid content, phenolic compounds content, activity of phenylalanine ammonium liase (PAL), polyphenol oxidase (PPO) and peroxidase (POD). The evaluation was made after 15, 30, 45 and 60 days of storage. The SA (1mM) and MeSA (0.05mM) were efficient to decrease internal browning incidence while the highest concentrations of SA caused phytotoxic effect in the fruit. The (0.05mM) was able in controlling of increase of pulp firmness. The 1-MCP was efficient to control the pulp internal browning; Intermittent warming and heat at 37°C for 3h were efficient to control internal browning in pulp of the fruit.

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Beauchêne, Solène. "Le Smart Thermogène Grid ® : étude des potentiels de récupération, de stockage et de redistribution des énergies fatales et renouvelables, optimisation et gestion d’un système intelligent intégrant l’ensemble des énergies disponibles dans le bâtiment." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2016. http://www.theses.fr/2016EMAC0002/document.

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Le projet Smart Thermogène Grid® s’intègre dans la dynamique actuelle d’économie d’énergie en s’intéressant à la mise en œuvre de solutions de récupération et de stockage des énergies fatales et renouvelables dans le bâtiment résidentiel. L’objectif de ce travail de thèse est de proposer une approche globale permettant le choix et le dimensionnement de ces systèmes. Ce manque freine leur intégration au sein du bâtiment ainsi que l’évolution du bilan énergétique. Dans ce contexte, une modélisation de type « boites grises » qui se base sur un assemblage de modules (récupérations sur air extrait, sur eaux usées et solaire, stockages géothermique et en cuve) a été développée. Ce type de démarche permet une simplification importante du modèle complet et une réduction considérable du nombre de paramètres à déterminer. Il devient alors possible de mettre en place une méthode d’optimisation sous contrainte de type GPS afin d’aboutir à un dimensionnement physique. Une solution discrète est ensuite proposée grâce à une recherche dans des bases de données. Il est ainsi possible de répondre à la problématique et de proposer un dimensionnement cohérent du SThG® The goal of the SThG® project is to recycle, to store and to manage unavoidable and renewable energies in the residential building. The aim of the work performed is to fill the lack of research on global sizing of systems, which is a barrier to the evolution of the energy balance of the building. Indeed, available tools are not adapted to make optimized choices and to size systems as they are very time-consuming. That is why an alternative model has been found. This work can be divided into two main steps. The first one, consists in doing a simplified model of a building and its systems. The second one in applying optimization to have the best choice and the better sizing of those systems according to energy and economic criterions. To solve this problem a model has been developed and two blocks can be identified. The first block is composed of two main points: the establishment of a physical model and the physical optimization. First, a macroscopic model of a building and its systems (recovery, storage and generation) has been created. This model is as much as generic as possible in order to represent a huge part of systems. But, it is also precise to ensure a good description of the real way they work and to allow the link to systems after the physical optimization during block two. Secondly, a Global Pattern Search optimization is used to find the best physical solution according to the constraints of the situation. The second block permits to find solutions in a discrete data basis of systems. These two blocks allow a durability of the tool, indeed the mechanism of optimization depends on the physical model. It will be possible to enrich the data basis of the second block without reconsidering the first one. Thanks to this work, a consistent choice and sizing of systems can be found

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30

Dini, Cosmin. "Mécanismes de traitement des données dans les réseaux de capteurs sans fils dans les cas d'accès intermittent à la station de base." Phd thesis, Université de Haute Alsace - Mulhouse, 2010. http://tel.archives-ouvertes.fr/tel-00576919.

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Les réseaux des capteurs sans fil sont considérés comme une alternative aux réseaux câblés afin de permettre l'installation dans des zones peu accessibles. Par conséquent, de nouveaux protocoles ont été conçus pour supporter le manque des ressources qui est spécifique à ce type de réseau. La communication entre les nœuds est réalisée par des protocoles spécifiques pour la gestion efficace de l'énergie. La gestion des données collectées par ces nœuds doit être également prise en compte car la communication entre les nœuds engendre un coût non négligeable en termes d'énergie. De plus, l'installation de ce type de réseau dans des régions lointaines facilite les attaques sur la structure des réseaux ainsi que sur les données collectées. Les mesures de sécurité envisagées amènent des coûts d'énergie supplémentaires. Un aspect souvent négligé concerne le cas où un nœud ne peut pas communiquer avec la station de base (sink node) qui collectionne et traite les données. Cependant, les nœuds continuent à accumuler des informations en suivant les plans de collection. Si la situation continue, l'espace de mémoire (storage) diminue à un point où la collection de nouvelles données n'est plus possible.Nous proposons des mécanismes pour la réduction contrôlée de données en considérant leur priorité relative. Les données sont divisées dans des unités auxquelles un niveau d'importance est alloué, en fonction des considérations d'utilité et de missions qui les utilisent. Nous proposons un ensemble de primitives (opérations) qui permettent la réduction d'espace de stockage nécessaire, tout en préservant un niveau raisonnable de résolution des informations collectées. Pour les larges réseaux à multiple nœuds, nous proposons des mécanismes pour le partage de données (data load sharing) ainsi que la redondance. Des algorithmes ont été proposés pour évaluer l'efficacité de ces techniques de gestion de données vis-à-vis de l'énergie nécessaire pour transférer les données.A travers des simulations, nous avons validé le fait que les résultats sont très utiles dans les cas à mémoire limitée (wireless nades) et pour les communications intermittentes.

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31

Eriksson, Pernilla, and Martin Sundell. "EXPLORING MARKET FORCES FOR TRANSMISSION EXPANSION AND GRID STORAGE INTEGRATION : A technical-economic thesis about variation moderators for intermittent renewable power generation in the developed country of Sweden and the developing country of China." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28560.

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Després, Jacques. "Modélisation du développement à long terme du stockage de l’électricité dans le système énergétique global." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT073/document.

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Le développement des énergies renouvelables éolienne et solaire implique de repenser les modèles à long terme du système énergétique. En effet, les impacts à court et long terme des productions intermittentes éolienne et solaire sur le système électrique entraînent un besoin de flexibilité : centrales de production très réactives, gestion de la demande,amélioration du réseau électrique ou stockage d’électricité. Le premier apport majeur à l’état de l’art est l’ajout du stockage d’électricité et du réseau électrique européen dans le modèle POLES (Prospective Outlook on Long-term Energy Systems). Un nouveau mécanisme d’investissement a été développé, mieux adapté aux enjeux des renouvelables ; il inclut plusieurs valeurs économiques du stockage. D’autre part, une nouvelle typologie applicable à la fois aux modèles de prospective énergétique et aux outils détaillés du secteur électrique,a montré l’intérêt de rassembler ces deux approches. Ainsi, la deuxième contribution principale est le couplage annuel de POLES à un modèle d’opération du système électrique,EUCAD (European Unit Commitment And Dispatch), qui optimise l’allocation technico économique des centrales européennes de production et de stockage. Les échanges bidirectionnels d’informations permettent de bénéficier à la fois de la cohérence à long terme des scénarios économiques de POLES et du détail technique d’EUCAD. Un scénario conservateur prévoit un développement rapide des options de flexibilité les moins chères :interconnexions, stockage hydraulique et gestion de la demande – que ce soit par des effacements de consommation ou par l’optimisation de la charge et décharge des batteries de véhicules électriques. Les batteries stationnaires, plus chères, sont développées en seconde partie de siècle. Leur développement pourrait être accéléré par une réduction des coûts fixes du stockage plus efficace qu’une amélioration du rendement. Les liens explicites entre renouvelables intermittents et stockage d’électricité ressortent aussi des résultats The current development of wind and solar power sources calls for an improvement of longtermenergy models. Indeed, high shares of variable wind and solar productions have shortandlong-term impacts on the power system, requiring the development of flexibility options:fast-reacting power plants, demand response, grid enhancement or electricity storage. Ourfirst main contribution is the modelling of electricity storage and grid expansion in the POLESmodel (Prospective Outlook on Long-term Energy Systems). We set up new investmentmechanisms, where storage development is based on several combined economic values.After categorising the long-term energy models and the power sector modelling tools in acommon typology, we showed the need for a better integration of both approaches.Therefore, the second major contribution of our work is the yearly coupling of POLES to ashort-term optimisation of the power sector operation, with the European Unit CommitmentAnd Dispatch model (EUCAD). The two-way data exchange allows the long-term coherentscenarios of POLES to be directly backed by the short-term technical detail of EUCAD. Ourresults forecast a strong and rather quick development of the cheapest flexibility options: gridinterconnections, pumped hydro storage and demand response programs, including electricvehicle charging optimisation and vehicle-to-grid storage. The more expensive batterystorage presumably finds enough system value in the second half of the century. A sensitivityanalysis shows that improving the fixed costs of batteries impacts more the investments thanimproving their efficiency. We also show the explicit dependency between storage andvariable renewable energy sources

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33

Carriere, Thomas. "Towards seamless value-oriented forecasting and data-driven market valorisation of photovoltaic production." Thesis, Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLM019.

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La décarbonation de la production d’électricité à échelle mondiale est un élément de réponse clé face aux pressions exercées par les différents enjeux environnementaux. Par ailleurs, la baisse des coûts de la filière photovoltaïque (PV) ouvre la voie à une augmentation significative de la production PV dans le monde. L’objectif principal de cette thèse est alors de maximiser le revenu d’un producteur d’énergie PV sous incertitude des prix de marché et de la production. Pour cela, un modèle de prévision probabiliste de la production PV à court (5 minutes) et moyen (24 heures) terme est proposé. Ce modèle est couplé à une méthode de participation au marché maximisant l’espérance du revenu. Dans un second temps, le couplage entre une centrale PV et une batterie est étudié, et une analyse de sensibilité des résultats est réalisée pour étudier la rentabilité et le dimensionnement de tels systèmes. Une méthode de participation alternative est proposée, pour lequel un réseau de neurones artificiel apprend à participer avec ou sans batterie au marché de l’électricité, ce qui permet de simplifier le processus de valorisation de l'énergie PV en diminuant le nombre de modèles requis The decarbonation of electricity production on a global scale is a key element in responding to the pressures of different environmental issues. In addition, the decrease in the costs of the photovoltaic (PV) sector is paving the way for a significant increase in PV production worldwide. The main objective of this thesis is then to maximize the income of a PV energy producer under uncertainty of market prices and production. For this purpose, a probabilistic forecast model of short (5 minutes) and medium (24 hours) term PV production is proposed. This model is coupled with a market participation method that maximizes income expectation. In a second step, the coupling between a PV plant and a battery is studied, and a sensitivity analysis of the results is carried out to study the profitability and sizing of such systems. An alternative participation method is proposed, for which an artificial neural network learns to participate with or without batteries in the electricity market, thus simplifying the process of PV energy valuation by reducing the number of models required

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Vega, Fausto Alfredo Canales. "Simulação e dimensionamento ótimo de sistemas autônomos híbridos com reservatórios hidrelétricos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/132970.

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O interesse mundial e os investimentos em fontes renováveis de energia têm aumentado consideravelmente nos últimos anos. Estas tecnologias têm a vantagem de aproveitar os recursos disponíveis localmente, reduzindo a dependência de fontes externas. Entretanto, um dos principais problemas associados a muitas das tecnologias de energias renováveis é sua imprevisibilidade ou intermitência. O armazenamento de energia é a técnica mais utilizada para moderar estas intermitências. Para aproveitamento em grande escala, os reservatórios hidrelétricos (de usinas hidrelétricas convencionais com reservatório e usinas hidrelétricas reversíveis) representam a tecnologia mais madura e amplamente aproveitada para armazenamento de energia elétrica na forma de energia potencial no volume de água. Isto faz destes uma opção importante a ser incluída no projeto de um sistema autônomo híbrido de geração de energia. Segundo diferentes autores consultados, o software HOMER (Hybrid Optimization Model for Electric Renewables) é a ferramenta mais amplamente utilizada em pesquisas relacionadas à simulação e configuração ótima deste tipo de sistemas. Esta tese apresenta um conjunto de procedimentos para determinar, em nível de pré-viabilidade, a configuração ótima (em termos do custo presente líquido) e o conjunto de arranjos viáveis de um sistema autônomo de geração de energia incluindo fontes renováveis intermitentes e reservatórios hidrelétricos. O software HOMER é aplicado na simulação e avaliação dos sistemas híbridos dos estudos de caso hipotéticos do presente trabalho, utilizados para validar os métodos propostos. Estes exemplos foram criados a partir de dados reais relacionados ao Estado de Rio Grande do Sul. Os procedimentos descritos são aplicáveis a qualquer região do mundo onde exista um local com potencial para reservatórios hidrelétricos, assim como dados de disponibilidade e custos relacionados a fontes renováveis intermitentes. Além de determinar a configuração ótima e o conjunto de arranjos viáveis, os resultados obtidos indicam que os procedimentos descritos podem ajudar na definição da melhor utilização de um local com potencial hidrelétrico. Igualmente, permitem estimar a quantidade de eletricidade excedente que poderia ser recuperada através de usinas reversíveis. Os resultados mostram que configuração ótima depende de muitos fatores, tais como restrições hidrológicas, a carga a ser atendida e o custo de geração de cada fonte. Global interest and investments in renewable energy sources has increased considerably in recent years. These technologies have the advantage of using locally available resources, reducing dependence on external energy sources. However, most renewable energy technologies suffer from an intermittent characteristic due to the diurnal and seasonal patterns of the natural resources needed for power generation. Energy Storage is the most used technique to buffer this intermittency. For large-scale applications, hydropower reservoirs (of conventional and pumped storage plants) are the most mature and the most widely employed technology for electricity storage in the form of potential energy. For this reason, a hydropower reservoir is a suitable option to consider including in an autonomous hybrid power system. According to many authors, the HOMER model (Hybrid Optimization Model for Electric Renewables) is the most widely used tool in research studies related to simulation and optimal design of this type of systems. This thesis presents some procedures to define, as a pre-feasibility assessment, the optimal configuration (in terms of Net Present Cost) and set of feasible designs of an autonomous hybrid power system that includes intermittent renewable energy sources and hydropower reservoirs. The HOMER software is used for simulating and evaluating the hybrid power systems of the hypothetical case studies, used to validate the proposed methods. These examples were created based on real data related to the State of Rio Grande do Sul, Brazil. The procedures described can be adapted to any other region of the world where exists a site suitable for the construction of hydropower reservoirs, along with available data regarding intermittent renewable sources and generation costs. Besides defining the optimal configuration and the set of feasible designs, the results indicate that the procedures explained could help in the definition of the best use of a site with hydropower potential. Likewise, these methods can also be used to estimate how much excess electricity can be recovered by means of pumped storage hydropower. The results show that the optimal system design depends on many factors such as hydrological constraints, average load to serve and energy cost of each source.

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Zeaiter, Ali. "Caractérisation et modélisation du comportement des alliages TiFe dédiés au stockage solide d'hydrogène. : Application à l'amélioration des performances d'un réservoir à hydrures métalliques." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD007/document.

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Les problèmes environnementaux et économiques, engendrés par l’usage des produits pétroliers, et la pénurie de ces énergies fossiles ont conduit à rechercher d’autres sources d’énergies, renouvelables et respectueuses de l’environnement. Nombre de ces sources sont intermittentes et nécessitent de prévoir des solutions de stockage. Le gaz de dihydrogène apparait comme un bon candidat pour remplir cette fonction. L’élément hydrogène, abondant dans la nature, présente sous sa forme gazeuse un pouvoir calorifique de 140 MJ/kg, soit 2,5 fois celui de l’essence. La filière ’hydrogène’ s’appuie sur 3 piliers : la production, le stockage-la distribution et l’utilisation. Le stockage d’hydrogène est traditionnellement réalisé par compression, sous des pressions allant de quelques bars à plusieurs centaines, et par liquéfaction à 20 K. La faible densité volumique de ces deux types de stockage (42 et 70 kgH2/m3) associée à de sérieux problèmes de sécurité et de conception mécanique, rend le stockage solide dans les alliages métalliques particulièrement pertinent pour certaines applications. Cette solution favorise le développement de réservoirs de conception sûre, compacts et ayant une grande densité volumique de 120 kgH2/m3 pour les alliages TiFe par exemple. Ce type d’hydrure a été retenu dans le cadre de ce travail parce qu’il présente des températures et pressions d’utilisation relativement proches des conditions ambiantes, mais aussi parce qu’il ne contient pas de terre rare d’utilisation relativement proches des conditions ambiantes, mais aussi parce qu’il ne contient pas de terre rare. La présente étude vise à caractériser et modéliser le comportement d’hydruration/déshydruration de l’alliage TiFe0.9Mn0.1, en vue d’améliorer ses performances lorsqu’il est intégré à un système de stockage. Dans un premier temps, nous nous sommes attachés à caractériser expérimentalement l’alliage TiFe0.9Mn0.1 sous forme de poudre en le décrivant sur les plans morphologique, chimique et thermodynamique. Ensuite, deux stratégies d’amélioration ont été testées, la première repose sur un traitement mécanique par broyage planétaire à billes, la deuxième considère un traitement thermochimique à température et durée de maintien données. Ces deux stratégies ont permis d’accélérer le processus d’activation de la poudre, mais le broyage planétaire à billes a détérioré de façon notable la cinétique apparente de désorption. Le traitement thermochimique n’a quant à lui pas dégradé les domaines d’équilibre et n’a donc pas eu d’effet néfaste sur les cinétiques de réaction. Les deux paramètres les plus importants de ce traitement, température et temps de maintien, ont été optimisés. D’autres paramètres restent à affiner.[...]La conception d’un système de stockage solide d’hydrogène exige la bonne compréhension des aspects macroscopiques, mais aussi microscopiques, de la réaction d’hydruration, et requiert donc des recherches complémentaires pour trouver de nouveaux axes d’amélioration de ses performances He environmental and economic problems caused by the use of petroleum products and the scarcity of these fossil fuels have led to the search for alternative sources of energy, which are renewable and respectful of the environment. Many of these sources are intermittent and require storage solutions. Hydrogen gas appears as a good candidate for this function. The hydrogen element, abundant in nature, has in its gaseous form a calorific value of 140 MJ / kg, i.e. 2.5 times that of gasoline. The 'hydrogen' sector is based on 3 pillars: production, storage, distribution and use. The storage of hydrogen is traditionally carried out by compression, under pressures ranging from a few bars to several hundreds, and by liquefaction at 20 K. The low density of these two types of storage (42 and 70 kgH2 / m3) associated with serious problems of safety and mechanical design, make solid storage in metal alloys particularly relevant for some applications. This solution favors the development of safe, compact design tanks with a high density of 120 kgH2/m3for TiFe alloys, for example. This type of hydride has been retained in this work because it has operating conditions of temperatures and pressures that are relatively close to ambient conditions, and also because it does not contain rare earth elements. The aim of this study is to characterize and model the hydriding/dehydriding behavior of the TiFe0.9Mn0.1 alloy, in order to improve its performance when it is integrated into a storage system. We first tried to characterize the alloy TiFe0.9Mn0.1 in powder form by describing it morphologically, chemically and thermodynamically. Then, two strategies of improvement were tested, the first one based on a mechanical treatment by planetary ball milling, the second considers a thermochemical treatment at given temperature and duration. Both strategies accelerated the process of powder activation, but the planetary ball milling significantly impaired the apparent desorption kinetics. The thermo-chemical treatment did not degrade the equilibrium domains and thus did not have an adverse effect on the reaction kinetics. The two most important parameters of this treatment, temperature and holding time, have been optimized. Other parameters remain to be refined.In addition to this experimental characterization, we have undertaken to describe the hydriding / dehydriding reaction macroscopically. The model allows to account for the thermodynamic response of the hydride within a reservoir. This work presents the results obtained on a tank containing 4 kg of TiFe0.9Mn0.1 powder when different hydrogen loading / unloading scenarios are considered: (i) loading / unloading under constant pressure, (ii) loading / unloading under an initial dose ( Method of Sievert), iii) loading / unloading under inlet or outlet flux of hydrogen. For each scenario, the effect of the coupling with a heat exchange system on the filling / emptying times is analyzed and optimal operating conditions are proposed. Finally, a sensitivity study using the Morris method is presented, and the most influential parameters of the model on the reaction rates are identified. The design of a solid hydrogen storage system requires a good understanding of the macroscopic as well as the microscopic aspects of the hydriding reaction and therefore requires further research to find new directions for improving its performance

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Wrzolek, Pierre. "Entwicklung neuer mononuklearer Wasseroxidations- und Sauerstoffreduktionskatalysatoren auf Basis des „Hangman“-Typs und deren Einsatz in der homogenen und heterogenen Katalyse." Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18032.

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Die vorliegende Arbeit befasste sich mit der Entwicklung neuer Hangmankomplexe, die auf ihre katalytischen Fähigkeiten bei der Wasseroxidation oder bei der Sauerstoffreduktion hin untersucht wurden. Diese beiden katalytischen Reaktionen sind von entscheidender Rolle bei der Speicherung erneuerbarer Energien in Form einer chemischen Bindung. Des Weiteren wurden im Rahmen dieser Arbeit mechanistische Studien an bekannten Katalysatorsystemen mittels verschiedener spektroskopischer Methoden durchgeführt. Als Referenzsystem bei der katalytischen Wasseroxidation diente der Komplex [Ru(tpy)(bpy)(OH2)]2+ (bpy = 2,2′-bipyridin, tpy = 2,2′;6′,2″-terpyridin), welcher nach einer bereits publizierten Vorschrift synthetisiert werden konnte. Durch die Kombination des bekannten Hangmansystems von NOCERA et al. mit dem Komplex [Ru(tpy)(bpy)(OH2)]2+ konnte eine neue Klasse von Wasseroxidationskatalysatoren geschaffen werden Die Hangmankomplexe konnten in sehr guten Ausbeuten synthetisiert und vollständig charakterisiert werden. Es konnte erstmalig gezeigt werden, dass diese Komplexe in der Lage sind, eine intramolekulare basenassistierte Wasseroxidation zu katalysieren. Bei der Verwendung des Hanmgankatalysators mit Iodidligang und Perchlorat als nicht koordinierenden Anions mit einer TON von 21,5 nach acht Stunden (beschränkt auf 25 Zyklen) im Vergleich zu den anderen Ruthenium Hangmankomplexen die größte katalytische Aktivität auf und stand damit im Vordergrund weiterer Untersuchungen. Durch die Verwendung von (NH4)2[Ce(NO3)6] (CAN) als Oxidationsmittel war die Katalyse des Hangmankomplexes in homogenen Katalysesystemen lediglich auf sehr niedrige pH-Werte beschränkt, was zur Verlangsamung der Katalysegeschwindigkeit (TOF) führte. Mittels UV-Vis-Spektroskopie konnte die Bildung hochvalenter RuIII-OH- und RuIV=O Intermediate durch schrittweise Oxidation des Rutheniumzentrums mit CAN nachgewiesen werden. Durch MALDI MS/MS Experimente ist es zudem gelungen, den Hangmaneffekt, der durch den Einbau einer Carbonsäurefunktion herbeigeführt wurde, zu beweisen, da die Existenz eines zweiten Wassermoleküls in der zweiten Koordinationssphäre bestätigt werden konnte. Dieser seltene Einblick legte nahe, dass ein zweites Wassermolekül durch Wasserstoffbrückenbindungen so in die Struktur eingelagert wurde, dass die Ausbildung der O O Bindung bei der Wasseroxidation unterstützt wird. Der Verwendung des Hangmankomplexes in heterogenen Katalysesystemen war ebenfalls erfolgreich: Durch den Einsatz von Nafion-beschichteten ITO-Glass-Elektroden war es gelungen, den Hangmankomplex auf einer Oberfläche zu immobilisieren. Dadurch konnten elektrochemische Untersuchungen in allen pH-Bereichen, ohne auf Löslichkeitseffekte und Oxidationsmittel Rücksicht zu nehmen, durchgeführt werden. Bei der Bestimmung der onset-Potentiale (Potential, bei dem die Wasseroxidation beginnt) in verschiedenen wässrigen Pufferlösungen zeigte der Hangmankomplex ein zum Referenzkomplex [Ru(tpy)(bpy)(OH2)]2+ stark verändertes Verhalten. Diese pH Abhängigkeit war auf den Protonierungszustand der freien Carbonsäuregruppe zurückzuführen ist. Durch die Auswertung der onset Potentiale war es möglich, den pks Wert der Carbonsäure abzuschätzen; dieser liegt bei etwa 4,6. Es konnte außerdem gezeigt werden, dass bei diesem pH Wert der Hangmankomplex, wie erwartet, eine maximale Umsatzfrequenz bei der Wasseroxidation besitzt; sie ist viermal höher als die des Referenzsystems [Ru(tpy)(bpy)(OH2)]2+. So erreichte der Referenzkomplex innerhalb der ersten Stunde der Elektrokatalyse eine TOF von 10,8 ± 0,11 h-1, welche durch den Hangmanliganden auf eine TOF von 45,6 ± 0,46 h-1 gesteigert werden konnte. Im Gegensatz dazu ließ sich bei den pH-Werten 3 und 7, wo die Carbonsäuregruppe vollständig protoniert bzw. deprotiert vorliegt, kein signifikanter Unterschied in der Katalyseaktivität beider Komplexe feststellen. Es ist demnach gelungen, die katalytische Aktivität von [Ru(tpy)(bpy)(OH2)]2+ durch den Einbau einer Hangmanfunktion signifikant zu steigern. Ein weiterer Schwerpunkt dieser Arbeit lag in der Synthese und Charakterisierung neuer Hangman porphyrinbasierter Sauerstoffreduktionskatalysatoren, welche durch Polymerisation auf intramolekulare Wechselwirkungen innerhalb des Polymers, die das katalytische Verhalten beeinflussen, untersucht werden sollten. Für die Polymerisation der Sauerstoffreduktions-katalysatoren wurden neue Porphyrinsysteme entwickelt. Diese bestanden einerseits aus para-bromphenylsubstituierten und andererseits aus 3 thiophensubstituierten Porphyrinen, welche als Hangmankomplexe und tetrafunktionalisierte Porphyrine synthetisiert und vollständig charakterisiert werden konnten. Die Polymerisation der Komplexe konnte über die meso-Substituenten am Porphyrinring durch Ni(COD)2 in einer YAMAMOTO-Polymerisation und mit CuI in einer SONOGASHIRA-Polymerisation, sowie oxidativ via Elektrolyse auf einer FTO beschichteten Glaselektrode erreicht werden. Gerade die Polymerisation der para-bromfunktionalisierten Porphyrine nach SONOGASHIRA zeigte eine sehr gute Reproduzierbarkeit. Es konnten mittels BET-Analysen gleichbleibend große Oberflächen für die gebildeten Polymere ermittelt werden. Die nachfolgenden elektrochemisch katalysierten Untersuchungen legten nahe, dass eine Aktivität in der Sauerstoffreduktion besteht. Jedoch wurde durch die Polymerisation der Komplexe keine Verbesserung der katalytischen Eigenschaften für die Hangmansysteme im Vergleich zu den unfunktionalisierten Systemen erreicht, was vermutlich an der Wahl des pH Werts liegt. Dennoch konnte präparativ eine Methode aufgezeigt werden, um einfache Porphyrine und Hangmanporphyrine zu polymerisieren und so für heterogene Katalysen zugänglich zu machen. Ein weiterer wichtiger Teil dieser Arbeit waren Untersuchungen von Hangmanporphyrinkomplexen mittels sowohl oberflächenverstärkter Resonanz-Raman-Spektroskopie (surface enhanced resonance Raman, SERR) als auch oberflächenverstärkter IR-Absorptions-Spektroskopie (surface enhanced-infrared-absorption, SEIRA). Dies waren die ersten Studien an immobilisierten Eisenporphyrinkomplexen, die den Einfluss der Carboxylgruppe der Hangmanfunktion auf eine mögliche Substrataktivierung analysierten. Dabei diente der Methylestergeschützte Komplex von NOCERA et al. bei allen Untersuchungen als Referenzsystem. Die beiden Komplexe Hangmanporphyrinkomplexe mit Eisen, mit freier und geschützter Carbonsäure, wurden auf einer Goldoberfläche auf einer selbstangeordneten Monolage (SAM), die mit Imidazol-Endgruppen versehen war, immobilisiert. Die Gold bzw. Silberoberfläche diente als Elektrode, um über Potentialveränderung das Redoxverhalten zu beobachten. Durch SEIRA Differenzspektren konnte der Protonierungsgrad der Carboxylgruppe bei verschiedenen pH-Werten bestimmt werden. Zu diesem Zweck wurde die Veränderung einer intensiven Bande bei 1737 cm-1 mit sinkendem pH Wert verfolgt. Über die normierte Intensität wurde eine Titrationskurve erhalten, mit deren Hilfe erstmalig direkt der pKs-Wert der Hangmangruppe (3,4 ± 0,2) bestimmt werden konnte. Durch zeitaufgelöste SERR Spektroskopie konnte die heterogene Elektronentransfergeschwindigkeit kHET für die Reduktion des Eisen(III)metallzentrums erhalten werden. Dabei wurde festgestellt, dass beim Methylester nur eine geringe Veränderung der kHET mit Variation des pH-Wertes auftritt, jedoch das Gegenteil für die freie Carbonsäure zutrifft. Hier verändert sich die kHET stark in Abhängigkeit vom pH-Wert und somit auch vom Protonierungsgrad der funktionellen Gruppe. Durch den Einsatz von deuterierten Pufferlösungen wurde für den geschützten Komplex kein kinetischer Isotopeneffekt gefunden, was sehr wahrscheinlich darauf zurückzuführen ist, dass die Methylesterfunktion nicht in den Redoxprozess am Eisenzentrum involviert ist. Anders ist es bei der freien Carbonsäure: Hier stieg die Elektronentransferrate um das etwa 10-fache an und ergibt folglich einen inversen kinetischen Isotopeneffekt. Mit Hilfe dieser Erkenntnisse aus den ermittelten Elektronentransfergeschwindigkeiten, dem Redoxverhalten von FeII/III und dem Protonierungsgrad der Carbonsäurefunktion ließ sich ein Mechanismus für die ablaufenden Prozesse postulieren, der im Wesentlichen von zwei Transferreaktionen ausgeht. Zum einen dem Elektronentransfer (ET) von der Elektrode zum Eisenzentrum und zum anderen von einem Protonentransfer (PT) zum sechsten Liganden am Eisenzentrum des Porphyrins. Durch die Interpretation der SERR- und SEIRA-Spektroskopie konnte bewiesen werden, dass der Protonierungsgrad der Carbonsäurefunktion am Hangmankomplex tatsächlich den ET und den PT beeinflusst. Nur unter neutralen und schwach basischen Bedingungen scheint ein PCET-Mechanismus am wahrscheinlichsten. Major fuel sources for the world’s energy supply are carbon-based (gas, oil, coal), with an associated emission of climate-damaging carbon dioxide. Therefore, we need a change from a fossil fuels based energy system to a system of renewable energy. The solution of these energy problems is the development of clean and sustainable fuel technologies. One possible pathway is the splitting of water into hydrogen and oxygen to drive a hydrogen based society. The oxidation of water into protons and dioxygen by a proton-coupled electron transfer (PCET) is the critical - high-energetic - half reaction of this process. [Ru(tpy)(bpy)(OH2)]2+ (bpy = 2,2′-bipyridine, tpy = 2,2′;6′,2″-terpyridine) is the archetype of many known single-site ruthenium complexes used for catalytic water oxidation. Its efficiency is likely influenced by installing a proton-donor/acceptor functionality in proximity to the catalytic site because the reaction mechanism is believed to occur by nucleophilic attack of a water molecule on a high-valent metal–oxo species assisted by hydrogen-bonding interactions. Thus, a new metal complex based on the „Hangman“ motive was synthesized and characterized. The known [Ru(tpy)(bpy)(OH2)]2+-unit is connected to a xanthene backbone with a carboxylic acid-function in proximity to the catalytic site. The proof of the catalytic activity and mechanistic investigations are the target of current work. Iron hangman complexes exhibit improved catalytic properties regarding O2 and H2O2 reduction, which are attributed to the presence of a proton donating group in defined vicinity of the catalytic metal centre. Surface enhanced resonance Raman (SERR) and IR (SEIRA) spectro-electrochemistry has been applied concomitantly for the first time to analyse such iron hangman porphyrin complexes attached to electrodes in aqueous solution. While the SERR spectra yield information about the redox state of the central iron, the SEIRA spectra show protonation and deprotonation events of the 2nd coordination sphere. To investigate the influence of a proton active hanging group on the heterogeneous electron transfer between the iron porphyrin and the electrode, two hangman complexes with either an acid or ester functional group were compared. Using time resolved SERR spectroscopy the electron transfer rates of both complexes were determined. Complexes with an acid group showed a slow electron transfer rate at neutral pH that increased significantly at pH 4, while complexes with an ester group exhibited a much faster, but pH independent rate. SEIRA measurements were able to determine directly for the first time a pKa value of 3.4 of a carboxylic hanging group in the immobilized state that shifted to 5.2 in D2O buffer solution. The kinetic data showed an increase of the heterogeneous electron transfer rate with the protonation degree of the acid groups. From these results, we propose a PCET which is strongly modulated by the protonation state of the acid hanging group via hydrogen bond interactions.

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Simpore, Sidiki. "Modélisation, simulation et optimisation d'un système de stockage à air comprimé couplé à un bâtiment et à une production photovoltaïque." Thesis, La Réunion, 2018. http://www.theses.fr/2018LARE0039/document.

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En raison de la variabilité et de l'intermittence de l'énergie solaire photovoltaïque, son intégration à grande échelle dans le mix énergétique des micros réseaux intégrant différents moyens de production demeure compliquée. En plus, cette variabilité de la ressource solaire ne permet pas l’utilisation du photovoltaïque seul pour des systèmes énergétiques autonomes. Une des solutions pour surmonter ces handicaps est le stockage d'énergie qui est généralement basé sur l’utilisation de batteries lithium-ion. Cependant, leur coût élevé et leur impact négatif sur l'environnement lors de l'extraction de leurs matières premières et lors de leur destruction ou de leur recyclage en fin de vie forcent à rechercher d’autres moyens de stockage. Dans cette thèse,nous avons modélisé et simulé un système de stockage d'énergie basé sur l'air comprimé (Compressed Air Energy Storage : CAES) qui semble être une bonne alternative au système à batterie compte tenu des désavantages cités plus haut. Cette technologie à air comprimé consiste à augmenter la pression de l’air dans une enceinte par le biais d’un compresseur alimenté par une source électrique. À ce jour, les systèmes de stockage à air comprimé existant sont basés sur des configurations à grande puissance avec des réservoirs souterrains tels que d’anciennes mines de sel ou de charbon, dont le stockage se fait sur une longue durée. Dans cette étude, nous présentons la modélisation, la simulation et l’optimisation d’un système de stockage à air comprimé d'une dizaine de kilowatts destiné à alimenter un bâtiment universitaire à énergie positive de façon instantanée à l’opposé des systèmes existants. Le modèle conçu reflète le fonctionnement en régime dynamique du système global composé du bâtiment, du champ photovoltaïque, du réseau électrique et du module de stockage à air comprimé. L’optimisation effectuée permet le dimensionnement d’un système de stockage à air comprimé pour un meilleur rendement (environ 55 %). L’intégration d’un récupérateur de chaleur muni de résistance électrique et l’introduction d’un module de compression à vitesse variable permettent au bâtiment alimenté de tendre vers l’autonomie énergétique à l’image d’un système à batterie pour un site isolé Due to the variability and intermittency of renewable energy such as solar technology, its large-scale integration into the micro-grid of energy production remains complicated because the large-scale photovoltaic power plants directly connected to the electricity grid may create instabilities. In addition, this variability of the solar resource does not allow the use of photovoltaics for the stand-alone system. Dealing with these issues, one of the solutions for a deployment of renewables such as photovoltaic is the set-up of energy storage inside the grid. However, the most common technique is based on the use of lithium-ion batteries, which remains not environmentally friendly during the recycling or during the destruction after their use. So, the Compressed Air Energy Storage system (CAES) appears as a solution to this disadvantage. In fact, my thesis aims to study the feasibility of this kind of energy storage technology using a small and medium photovoltaic power plant, and its instant operation to supply electricity to the buildings and the unconnected areas. In this thesis, we present the modeling, simulation, and optimization of a ten-kilowatt compressed air storage system designed to supply instantly a building with real loads. The model performed reflects the dynamic operation of the overall system consisting of the building, the photovoltaic field, the electrical grid, and the compressed air storage module. The optimization carried out allows the sizing of a compressed air storage system with a better efficiency (about 55%). The integration of a heat recovery unit equipped with electrical resistance and the adding of a variable speed compression module allow the building to reach the energy autonomy as a battery system for a standalone site

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Amicarelli, Elvira. "Stratégies de gestion des réseaux électriques intelligents à fort taux de production renouvelable distribuée." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT056/document.

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En 2007 avec la directive sur les énergies renouvelables, l’Union Européen s’est engagée à développer une économie à faible intensité de carbone. Cette directive amène à réduire les émissions de gaz à effet de serre en augmentant entre autres la partie d’énergie produite par des sources renouvelables. Le processus d’insertion massive d’énergies renouvelables dans le mix électrique européen, est d’ores et déjà un fait acquis et ses effets sont tangibles. Cependant, à côté de ses effets environnementaux bénéfiques, l’intégration à large échelle du renouvelable ne va pas sans causer des interrogations techniques et réglementaires. Par conséquent, de nouvelles stratégies de gestion du système électrique doivent être pensées et actées pour garantir un fonctionnement fiable et économiquement acceptable. Les micro réseaux sont à cet effet, un réceptacle intégrateur avec suffisamment de flexibilité pour accueillir un système de gestion capable de répondre aux exigences ci-dessus. Les travaux de cette thèse sont centrés sur la conception, le développement et l’implémentation de différentes stratégies de gestion des micro réseaux. Les algorithmes développés visent, soit à faciliter l’intégration du renouvelable à large échelle, soit à garantir un fonctionnement efficace et économique du système électrique. Une nouvelle architecture de réseau de distribution composé de micro réseaux clustérisés a été premièrement proposée. Chaque micro réseau est composé de systèmes de production à base ou non de renouvelable, des systèmes de stockage et de charges. Une stratégie de gestion énergétique optimale a été ensuite définie et développée. Cette stratégie permet de gérer la planification à court-terme et le contrôle en temps-réel des micro réseaux via un usage adéquat des sources et ce, tout en réduisant le coût du micro réseau. Un système multi-agents et l’optimisation linéaire mixte en nombres entiers ont été utilisés pour le développement et l’implémentation de cette stratégie intelligente distribuée. D’un point de vue extérieur, chaque micro réseau est vu comme une entité cohérente capable de supporter le fonctionnement du réseau principal en utilisant un ensemble de ses sources flexibles. Ainsi, que la seconde partie de cette thèse exploitera les clusters des micro réseaux et leurs propriétés pour gérer au mieux le réseau de distribution hôte. La conceptualisation technico-économique de différents mécanismes de gestion des réseaux de distribution a été abordée. Le développement d’une architecture de gestion hiérarchisée en plusieurs niveaux d’intelligence a permis de réduire la complexité du système et faciliter l’implémentation d’un réseau flexible, extensible et à fort taux de pénétration de renouvelables. Cette gestion distribuée a été possible grâce à une connaissance locale des modèles et des comportements des différentes systèmes connectés, et à un usage local des informations. Les travaux théoriques ont été ensuite testés sur une plateforme expérimentale conséquente et les résultats finaux ont corroboré les attentes de la théorie In 2007 with the renewable energy directive, the European Union established the development of a low-carbon economy. This directive aims to decrease greenhouse gas emissions by increasing the energy produced by renewable energy. Already today, the massive diffusion of renewable systems is tangible in the European electricity mix. However, in spite of their potential benefits, their large-scale integration leads to new technical and regulatory questions. Consequently, new management strategies need to be developed and applied in order to ensure a reliable and economical operation of the system. Microgrids are considered to be one of the most effective and flexible solutions able to meet these new needs.The main goals of this thesis are the conceptualization, development and implementation of different management strategies for microgrids. The algorithms developed aim to facilitate the massive integration of renewables and at the same time lead to an effective and economic operation of the systems. A new architecture of distribution grids based on cluster of microgrids was proposed. Each microgrid is composed of a number of renewable-based and conventional generation systems, storage systems and consumption. An optimal and distributed energy management strategy was then defined and developed. This strategy allows to manage the short-term energy management and real-time control of microgrids by using the connected sources in a smart and cost-efficient way. A multi-agent system and the mixed integer linear optimization technique were used for the implementation of this strategy.From a global point of view, each microgrid is seen as a coherent entity, which can support network operation by using its flexible and aggregated sources. Hence, the second part of this thesis aims to understand how distribution grids can exploit these cluster of microgrids and their properties. Different mechanisms for the active management of distribution grids are conceptualized from the technical and economical point of view. A new strategy based on hierarchical management of different smart levels allow to reduce the complexity of the system and to implement a more flexible and extensible system, thanks to a more local use of model knowledge and users behaviour. On the end, the theoretical work were tested on an experimental test-bed in order to show the effectiveness of the proposed theories

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Marguerite, Charlotte. "Modèles intégrés pour l'évaluation des actions territoriales de réduction des émissions de gaz à effet de serre. Application aux réseaux de chaleur : Application aux réseaux de chaleur : HeatGrid, un modèle de simulation énergétique pour un management stratégique." Phd thesis, Ecole des Mines de Nantes, 2014. http://tel.archives-ouvertes.fr/tel-01019088.

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Du fait de la flexibilité énergétique qu'ils offrent et de leur potentiel de diminution des émissions de GES et de polluants, les réseaux de chaleur (RdC) sont un des leviers d'actions des politiques énergétiques locales en constante progression. Leur déploiement et/ou rénovation n'est pas qu'une question technico-économique classique, dans la mesure où ils sont au cœur d'un ensemble d'acteurs interconnectés, aux objectifs spécifiques, tous parties prenantes des politiques énergétiques locales. Dans ce contexte, les outils permettant à ces différents acteurs l'évaluation des actions liées aux RdC sont très importants. Ils doivent permettre l'évaluation de scénarios de conception, d'actions de rénovation, de performance et de suivi... Parmi les outils permettant ces évaluations, les approches par modélisation sont souvent trop spécifiques à une situation, un type de réseau un acteur... Le travail réalisé consiste à développer un outils de modélisation de RdC, offrant la flexibilité recherchée. "HeatGrid" permet de modéliser des architectures de réseaux variées. A chaque pas de temps, le fonctionnement du réseau est simulé grâce au formalisme de la programmation linéaire. Cet outil peut être utilisé en phase de conception ou d'exploitation d'un réseau. L'approche de modélisation permet d'évaluer et de comparer sous les aspects économiques, énergétiques et techniques d'un RdC sous différents scénarios. Plusieurs exemples sont simulés et analysés dans le but d'illustrer le potentiel du modèle.

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Júnior, Jorge Paulo Cabral. "Recursos energéticos distribuídos numa rede elétrica: um estudo de caso." Master's thesis, Instituto Politécnico de Setúbal. Escola Superior de Tecnologia de Setúbal, 2019. http://hdl.handle.net/10400.26/31356.

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Dissertação do Mestrado em Engenharia Eletrotécnica e de Computadores - Ramo de Energias Renováveis e Sistemas de Potência A redução das emissões de CO2 na atmosfera, requer apostas em soluções sustentáveis, sendo uma delas a integração de energias renováveis variáveis (ERV) na rede. A transição para sistemas em que existe forte penetração de ERV, exige o aumento de flexibilidade do sistema elétrico. Um dos requisitos para garantir essa flexibilidade, é o armazenamento de energia. O armazenamento de energia permite mitigar vários problemas na rede, entre eles, a duck curve. Foi realizado o estudo sobre o impacto do armazenamento no diagrama de carga da subestação São João, em Coimbra, na presença de geração fotovoltaica e eólica. Os resultados obtidos permitiram concluir que o armazenamento de energia, é um requisito necessário para que o sistema elétrico tenha flexibilidade, após a penetração da geração fotovoltaica distribuída. O armazenamento através da geração eólica na rede, pode auxiliar na redução da rampa do consumo durante o final do dia. Com este método, foi possível diminuir o efeito duck curve, através do peak shaving. A maioria da energia eólica armazenada foi durante o dia, em que existe consumo reduzido na rede, devido à massiva geração fotovoltaica. Quanto maior for a geração eólica, nos períodos de baixo consumo, maior é a necessidade do armazenamento. The reduction of carbon pollutions requires betting on sustainable solutions, one of them is the integration of variable renewable energies (VRE) in the grid. The transition to systems where there is a higher penetration of VRE, requires increased power system flexibility. One of the requirements to ensure this flexibility is energy storage. Energy storage enables mitigate several problems on the grid, including the duck curve. The study of the impact of storage on the load diagram of the São João substation, in Coimbra, in the presence of photovoltaic and wind production was carried out. The results obtained allowed to conclude that the storage of energy, is a necessary requirement for the electrical system to have flexibility, after integration of distributed photovoltaic production. Wind production and storage system can help reduce the ramp consumption during the end of the day, where there is no photovoltaic production. It was possible to decrease the effect caused by duck curve, through peak shaving. Most of the wind energy stored was during the day, when the consumption in the grid is low, due massive photovoltaic production. Increased wind production requires increased storage capacity.

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Huet, Lila. "Role of electric flexibility in the future French grid with high renewable integration." Thesis, KTH, Energiteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263063.

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The operation of electric grids depends on the balance between the electric generation and the demand. In France, the Transmission System Operator, RTE, is responsible for the stability and the security of the grid. Today, the electric generation follows the variations of the demand. However, environmental concerns prompt to develop new strategies and policies for Energy Transition. The development of Smart Grids, the uncertain future of nuclear generation, the massive integration of renewable sources are the focus of those. Furthermore, renewable energies generation is intermittent and can not be controlled. The current strategy for the balance between generation and demand is challenged. The electric grid has to be readjusted by adding more electric flexibility to ensure its stability. The electric flexibility is usually associated to storage technologies as batteries or pumping stations. A state of art review is used to define this notion and to evaluate the technological and economic maturity of different electric flexibility vectors. The following report is based on a selection of prospective scenarios, development plans already launched in France, proposing a significant share of renewable energies in a future energy mix and current French energy data. Two studies were carried out : one at a regional level, for Bretagne and one at national level for France. An evaluation at 2050 is carried out to determine the load factors of intermittent energies, consumption and residual demand in Bretagne. On the basis of these prospective estimates, a need for electric flexibility can be determined for the Bretagne region. This first study highlights an issue related to future needs for electric flexibility. However, since the balance between production and consumption is achieved at a national level, a second study on France is necessary. The French need for electric flexibility is then estimated through a linear optimization that evaluates the energy production required to achieve a generation/consumption balance taking into account energy sources merit order. Det franska elnätets funktion beror på balansen mellan elproduktionen och efterfrågan. Transmissionssystemoperatören, RTE, ansvarar för nätets stabilitet och säkerhet. Idag följer den elektriska generationen variationerna i efterfrågan. Miljömässiga frågor är emellertid snabba för att utveckla nya strategier och strategier för energiövergång. Utvecklingen av Smart Grids, den osäkra framtiden för kärnkraftsproduktion, den massiva integrationen av förnybara källor är deras fokus. Vidare är generering av förnybara energikällor intermittent och kan inte kontrolleras. Den nuvarande strategin för balans mellan produktion och efterfrågan utmanas. Elnätet måste justeras genom att lägga till mer elektrisk flexibilitet för att säkerställa stabiliteten. Den elektriska flexibiliteten är vanligtvis förknippad med lagringsteknik som batterier eller pumpstationer. En allmänt erkända tekniska används för att definiera denna uppfattning och att utvärdera den tekniska och ekonomiska mognaden hos olika elektriska flexibilitetsvektorer. Följande undersökningar grundar sig på ett urval av framtida scenarier, utvecklingsplaner som redan lanserats i Frankrike, och föreslår en betydande andel förnybara energikällor i en framtida energimix och nuvarande franska energidata. Två studier utfördes på olika perimetrar: på Bretagne-regionen och i Frankrike. En utvärdering vid 2050 utförs för att bestämma belastningsfaktorerna för intermittent energi, förbrukning och återstående efterfrågan i Bretagne. På grundval av dessa framtida uppskattningar kan ett behov av elektrisk flexibilitet bestämmas för Bretagne-regionen. Denna första studie lyfter fram ett problem som rör framtida behov av elektrisk flexibilitet. Men eftersom balansen mellan produktion och konsumtion uppnås på nationell nivå krävs en andra studie om Frankrike. Det franska behovet av elektrisk flexibilitet uppskattas sedan genom en linjär optimering som utvärderar den energiproduktion som krävs för att uppnå en generation / konsumtionsbalans med hänsyn tagen till energikällans meriteringsordning. Le fonctionnement du réseau électrique français repose sur l’équilibre entre la production et la consommation d’électricité. Le gestionnaire du réseau de transport, RTE, est responsable de la stabilité et de la sécurité du réseau. Aujourd’hui, la production électrique s’adapte aux variations de la consommation. Cependant, des préoccupations environnementales incitent à la mise en place de nouvelles stratégies et politiques pour la transition énergétique. Le développement d’un réseau intelligent, l’avenir incertain du nucléaire et l’intégration massive d’énergies renouvelables sont au centre de celles-ci. De plus, la production électrique des énergies renouvelables s’avère intermittente et fatale. La stratégie actuelle du maintien de l’équilibre production/consommation est remise en question. Le système électrique doit être repensé en y intégrant plus de flexibilité électrique pour en garantir la stabilité. La flexibilité électrique est usuellement associée aux technologies de stockage comme les batteries électrochimiques et les STEP hydrauliques. Un état de l’art permet de définir précisément cette notion et d’évaluer la maturité technologique et économique en France de ces différents vecteurs de flexibilité électrique. L’objet des recherches suivantes est basé sur une sélection de scénarios prospectifs, de plans de développement d’ores et déjà lancés en France, proposant une part importante d’énergies renouvelables dans un futur mix énergétique et des données énergétiques actuelles françaises. Deux études ont été menées sur différents périmètres : sur la région Bretagne et sur la France entière. Une évaluation à 2050 est effectuée pour déterminer facteurs de charge des énergies intermittentes, consommation et demande résiduelle en Bretagne. A partir de ces estimations prospectives, un besoin en flexibilité peut être déterminé sur le périmètre de la Bretagne. Cette première étude permet de mettre en exergue une problématique liée aux futurs besoins de flexibilité électrique. Cependant, l’équilibre entre production et consommation étant réalisé à un niveau national, une seconde étude sur le périmètre français est nécessaire. Le besoin français en flexibilité est alors estimé par le biais d’une optimisation linéaire qui évalue la production énergétique nécessaire pour obtenir un équilibre production/consommation en tenant compte de la préséance économique.

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Saulich, Sven. "Generic design and investigation of solar cooling systems." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/13627.

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This thesis presents work on a holistic approach for improving the overall design of solar cooling systems driven by solar thermal collectors. Newly developed methods for thermodynamic optimization of hydraulics and control were used to redesign an existing pilot plant. Measurements taken from the newly developed system show an 81% increase of the Solar Cooling Efficiency (SCEth) factor compared to the original pilot system. In addition to the improvements in system design, new efficiency factors for benchmarking solar cooling systems are presented. The Solar Supply Efficiency (SSEth) factor provides a means of quantifying the quality of solar thermal charging systems relative to the usable heat to drive the sorption process. The product of the SSEth with the already established COPth of the chiller, leads to the SCEth factor which, for the first time, provides a clear and concise benchmarking method for the overall design of solar cooling systems. Furthermore, the definition of a coefficient of performance, including irreversibilities from energy conversion (COPcon), enables a direct comparison of compression and sorption chiller technology. This new performance metric is applicable to all low-temperature heat-supply machines for direct comparison of different types or technologies. The achieved findings of this work led to an optimized generic design for solar cooling systems, which was successfully transferred to the market.

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Ferreira, Pedro Cardoso de Lemos. "Requisitos de Flexibilidade para a Integração em Larga Escala de Energia Solar Fotovoltaica." Master's thesis, 2019. http://hdl.handle.net/10316/87974.

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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia A transição energética dos combustíveis fósseis para as energias renováveis é o grande desafio do século XXI e a energia solar fotovoltaica assume um papel fundamental para a garantir. Os avanços tecnológicos estão a permitir tornar cada vez mais rentável a energia solar fotovoltaica, pelo que é expectável um crescimento significativo da sua potencia instalada a nível mundial. Portugal é dos países com maior índice de radiação solar da União Europeia, e apesar da baixa capacidade instalada atual, prevê-se que o fotovoltaico será a fonte com maior crescimento nos próximos anos, podendo no futuro ser a principal fonte de energia do país. Posto isto, a avaliação dos impactos que a penetração da energia solar fotovoltaica em larga escala tem na gestão do sistema electroprodutor torna-se fundamental.A presente dissertação tem por objetivo compreender qual o impacto que o crescimento da energia solar fotovoltaica terá na gestão dos sistemas de energia elétrica e avaliar tecnologias capazes de mitigar a sua variabilidade, nomeadamente tecnologias de armazenamento de energia ou de gestão da procura. Os sistemas de armazenamento permitem assegurar reserva operacional, armazenando o excesso de energia das horas de maior produção e menor procura e descarregar nas horas de ponta dos diagramas de carga. A gestão da procura complementa esta tecnologia reduzindo a necessidade de investimento em baterias de maior capacidade. Analisaram-se cenários futuros com base nas previsões de crescimento da potência instalada do fotovoltaico em Portugal para 2021 (1,6 GW) e 2030 (6 GW), estudou-se os impactos e analisaram-se possíveis soluções. Para o dia referente à primavera o aumento da potência para 6 GW permitiu reduzir em 6,65 GWh a geração a gás natural e evitar a importação de 1,3 GWh. A introdução de uma bateria com capacidade de 1,866 GWh permitiu reduzir em 1317 MWh a importação e em 2952 MWh o excesso de renováveis face ao consumo, correspondendo a 14,78% do referido excesso.Em suma pode-se afirmar que o crescimento da energia solar fotovoltaica e a intermitência da mesma exigem um sistema electroprodutor flexível. Nesse contexto, os sistemas de armazenamento e a gestão da procura são fundamentais para garantir a flexibilidade, mantendo o sistema de energia elétrica em equilíbrio. The energy transition from fossil fuels to renewable energies is the great challenge of the 21st century and solar photovoltaics plays a key role in it. The technological advances are making solar photovoltaics more profitable, therefore a significant increase in the worldwide installed power is expected. Portugal is one of the countries with the highest solar radiation index in the European Union, despite the current low installed capacity. However, photovoltaic is expected to be the fastest growing source in the coming years and can be the country's main source of energy in the future. Therefore, the assessment of the impacts of the large-scale penetration of photovoltaic power on power generation systems and its management becomes indispensable.The aim of this dissertation is to understand the impact of the growth of photovoltaic power in the management of electrical systems and to evaluate technologies capable of mitigating their variability, namely energy storage or demand-side management technologies. Storage systems can ensure operational reserve, storing the energy surplus in hours of higher generation and lower demand and discharge at periods of high demand. Demand-side management complements this technology by reducing the need for investment in batteries with large capacity.Future scenarios were analyzed based on forecasts for the growth of the installed photovoltaic power in Portugal for 2021 (1.6 GW) and 2030 (6 GW), being studied the impacts and analyzed possible solutions. For the spring day, the increase in power to 6 GW allowed to reduce natural gas generation by 6.65 GWh and to avoid the import of 1.3 GWh. The introduction of a battery with a capacity of 1,866 GWh enabled the reduction of imports by 1317 MWh and the renewable generation surplus of renewables relatively to the consumption by 2952 MWh, corresponding to 14.78% of such surplus.It can be concluded that the growth of photovoltaic power and its intermittence will require a flexible power generation system. In this context, storage systems and demand-side management are critical to ensuring flexibility by keeping the power system in balance.

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Nunes, Rui Jorge Passos Lopes. "Planeamento de Sistemas de Energia 100% Renováveis." Master's thesis, 2017. http://hdl.handle.net/10316/83419.

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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia A integração de fontes renováveis no sector elétrico é uma realidade na maioria dos países europeus. O tema assume uma grande importância no sentido em que permite o aproveitamento dos próprios recursos energéticos, diminuindo a necessidade de matérias primas importadas, cuja utilização é responsável por problemas ambientais. No entanto, a intermitência das fontes renováveis obriga a um planeamento da sua implementação, de forma a avaliar o seu potencial, mas também as alternativas para os períodos de geração mais reduzida. A presente dissertação de Mestrado Integrado em Engenharia Eletrotécnica e de Computadores, na área de especialização de Energia, tem como objetivo o estudo do planeamento de Sistemas de Energia Elétrica 100% renováveis. Para tal, foi realizada uma simulação fiel do Sistema Elétrico de Portugal Continental no ano de 2016. Tal serviu de base para a elaboração de cenários futuros, até ao ano de 2040, tendo em conta previsões relacionadas com o aumento da produção de origem renovável e da diminuição da produção proveniente de combustíveis fósseis. Os cenários elaborados tiveram em conta as características específicas do Sistema Elétrico Português, tanto no que diz respeito à aposta em tecnologias renováveis especificas e vistas com maior potencial de desenvolvimento, mas também às limitações impostas pelas condições geográficas do país e pela inviabilidade do investimento em outras tecnologias que já estão a atingir o seu potencial máximo aproveitável. A ferramenta utilizada durante o desenvolvimento deste trabalho foi o EnergyPLAN, um software de simulação de sistemas de energia que assegura a sua avaliação com base na distribuição do consumo e da disponibilidade das fontes renováveis intermitentes, permitindo avaliar com detalhe as evoluções dos sistemas simulados. O trabalho visa sobretudo uma análise técnica a longo prazo com base nos problemas que resultam da intermitência das fontes renováveis consideradas, que originam períodos de escassa geração e outros de geração em excesso, e na forma como o Sistema Elétrico será capaz de lidar com os mesmos para a garantir a sua fiabilidade. É avaliada a possibilidade da operação de um Sistema Elétrico 100% renovável recorrendo a soluções de armazenamento de energia, nomeadamente a baterias de iões de lítio, de forma a assegurar a fiabilidade do sistema. Concluiu-se que tal é tecnicamente possível, mas que não é economicamente viável. The integration of renewable energy sources in the electricity sector is a reality in most European countries. The subject becomes very important since it allows the use of internal energy resources, reducing the need of imported fuels that are responsible for environmental problems. However, the intermittence of renewable energy sources requires the planning of its implementation in order to evaluate its potential, as well as alternatives for periods with low generation levels. This Master thesis in Electrical and Computer Engineering in the specialization of Energy aims to study the planning of 100% renewable energy systems. For this purpose, a simulation for the mainland Portuguese electricity system in 2016 was developed. Such simulation was used as starting point for the development of future scenarios, until 2040, considering forecasts related with the increase of renewable energy generation and decrease of fossil fuels based generation. The developed scenarios take into consideration the specific characteristics of the Portuguese Electric System, considering not only the focus on specific renewable technologies with larger potential for development, but also the limitations imposed by the geographical conditions of the country and the inviability of the investment in technologies already reaching its maximum usable potential. The tool used during the development of this work was EnergyPLAN, a software for the simulation of energy systems that ensures its assessment based on the distribution of the consumption and the availability of the intermittent renewable sources, allowing to observe in detail the evolutions of the simulated systems. The work mainly aims to present a long-term technical analysis based on the problems created by the intermittency of the considered renewable generation sources, that result in periods with lack or surplus generation, and in the way how the Electrical System will be able to deal with such problems to ensure its reliability. The possibility of operating a 100% Renewable Electric system is evaluated using energy storage solutions, in particular lithium ion batteries. It was concluded that such option is technically possible, but not cost-effective.

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Ferreira, Diogo Francisco Nascimento. "Avaliação de tecnologias para a integração em larga escala de energia solar fotovoltaica." Master's thesis, 2017. http://hdl.handle.net/10316/82926.

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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia As energias renováveis apresentam-se cada vez mais como o futuro do cenário energético mundial. Portugal oferece condições climatéricas privilegiadas para a integração deste tipo de energias, com especial destaque a energia solar fotovoltaica, sendo um dos países com maior índice de radiação solar na Europa. Contudo, a mudança do sistema atual, fortemente dependente de sistemas de geração previsíveis e controláveis, para um sistema totalmente renovável, necessita do devido planeamento por forma a que se possam solucionar os problemas associados como a geração intermitente.A presente dissertação pretende apresentar e avaliar as principais tecnologias que podem ser utilizadas para solucionar os problemas da integração em larga escala de energia solar fotovoltaica. A utilização de sistemas de armazenamento de energia, foi a tecnologia que apresentou melhores resultados em larga escala, permitindo quando utilizados como reserva operacional, armazenar a energia em excesso e descarregar a mesma quando necessário, suavizar e estabilizar os diagramas de carga, regular e controlar a frequência, reduzir a energia importada e evitar o uso de fontes nocivas ao meio ambiente.Estimou-se um cenário futuro através da ampliação da potência instalada fotovoltaica em 2016, tendo-se obtido excesso de geração maioritariamente nas estações de inverno e primavera (aumento do excesso em 119,2% e 405,7% respetivamente). Através da simulação feita, concluiu-se que, para uma média anual, o sistema de baterias de iões de lítio permitiu armazenar 62,5% da energia em excesso e conseguiu satisfazer 39,6% das necessidades energéticas. Como conclusão final, pode-se afirmar que a introdução de sistemas de baterias de iões de lítio permite assegurar as necessidades energéticas e minimizar os impactos da crescente implementação da larga escala de energias renováveis intermitentes. Renewable energies are increasingly becoming the future of the global energy sector. Portugal has privileged climacteric conditions to integrate this type of energy with emphasis on solar photovoltaic power, being one of the countries with the highest solar radiation index in Europe. However, the shift from the current, heavily dependent on predictable and controlled generation systems, for a fully renewable system, needs proper planning to mitigate problems associated to the intermittent generation.The present dissertation intends to evaluate the potential impact of the large-scale integration of photovoltaic solar power and assess the main technologies that can be used to solve the problems of its intermittence. The use of energy storage systems was the technology that presented better results on a large scale, by allowing, when used as an operating reserve, to store the surplus generation and discharging it when necessary, by smoothing the load diagrams, control frequency, reduce imported energy and avoid the use of harmful sources to the environment.A future scenario was estimated through the expansion of the photovoltaic installed capacity in 2016, being obtained a generation surplus on winter and spring (the surplus was increased by 119.2% and 405.7%, respectively). Trough the simulation, it was concluded that for an annual average the lithium-ion battery system ensured the storage of 62.5% of the generation surplus and fulfilled 39.6% of the energy needs. It can be concluded that the implementation of lithium-ion battery energy systems ensures the energy needs and mitigate the impacts of the increasing implementation of renewable energies on a large scale.

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Ferreira, João António Alves. "Análise técnica e económica de tecnologias de armazenamento de energia elétrica para a integração em larga escala de geração renovável intermitente." Master's thesis, 2017. http://hdl.handle.net/10316/83049.

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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia Renewable energies are the obvious option to ensure a sustainable future. The wide availability and diversity of natural energy resources allows the development of flexible generation technologies adapted to the needs of electric power systems. In Portugal, the potential of wind, solar and hydro power enable an energy future mainly based on renewable energy. However, changing from predictable and easily controllable fossil energy systems, to systems that use natural energy sources has a strong impact on the generated energy profile. Inconstant levels of generation, difficulties to match the consumption levels, and difficulty in ensuring a correct management of the systems are only some of the problems inherent to this type of renewable intermittent energy. Among the different solutions that reduce these problems, the use of an operating reserve by large-scale storage systems produce the best results. By storing excess energy and discharging when necessary, these grid-connected systems can smooth the load diagrams, reduce imported energy values, and avoid the use of environmentally harmful energy sources. Following an analysis of the technical specifications of the currently known systems, were chosen the 4 most suitable systems for use with intermittent power generation were selected. The systems selected were compress air energy storage (CAES), conventional lithium ion batteries (Li-ion), sodium-sulfur (NaS) batteries and Vanadium redox (VRB) flow batteries.In this dissertation, an algorithm was created in Matlab® able to simulate the impact caused by each of the storage system on the load diagrams of the preselected case studies. After obtaining the results using the algorithm, a technical and economic analysis of the energy exchanges and energy costs for each of the systems was done. At the end, an analysis of the systems that provide energy at a lower cost and with greater efficiency to solve problems related to intermittent power generation is done. As energias renováveis são a melhor opção para garantir um futuro sustentável. A grande disponibilidade e diversidade de fontes de energias naturais levou ao desenvolvimento de tecnologias de geração flexíveis adaptadas às necessidades dos sistemas de energia elétrica. Em Portugal, o potencial da energia eólica, solar e hídrica permitem um futuro energético maioritariamente baseado em energias renováveis.No entanto, a mudança de sistemas de geração fóssil previsível e facilmente controlável para sistemas de geração dependentes de fontes de energia naturais variáveis tem um forte impacto no perfil da energia gerada. Níveis de geração inconstantes, incapacidade de garantir os níveis de energia consumida, e dificuldade em realizar uma correta gestão dos sistemas são apenas alguns dos problemas inerentes a este tipo de energia renovável intermitente. De entre as diferentes soluções existentes que permitem atenuar os problemas referidos, a utilização de reserva operacional baseada em sistemas de armazenamento de larga escala é a que apresenta melhores resultados. Armazenando energia em excesso e descarregando quando necessário, estes sistemas interligados com a rede elétrica permitem suavizar os diagramas de carga, reduzir os valores de energia importada e evitar a utilização de fontes de energia nocivas para o ambiente. Após uma análise das especificações técnicas dos sistemas atualmente conhecidos, foram selecionados os 4 sistemas mais adequados para a utilização com geração de energia intermitente, nomeadamente sistemas de armazenamento de comprimido, de baterias convencionais de iões de lítio, de baterias de sódio-enxofre e de baterias de fluxo de redox de vanádio.Para esta dissertação foi criado um algoritmo em Matlab® capaz de simular as variações causadas por cada um do sistema de armazenamento nos diagramas de carga de casos de estudo selecionados. Após obtenção dos resultados através do algoritmo, foi realizada uma análise técnica e económica das trocas de energia e dos custos de energia de cada um dos sistemas com a rede ao longo de um ano. No final foram apresentados quais os sistemas que fornecem energia a um custo mais reduzido e mais adequados para a resolução dos problemas relacionados com a geração de energia intermitência.

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(9910323), Haizhen Wang. "Development of Sustainable Energies from Solar." Thesis, 2021.

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Energy occupies a pivotal position in the development and progress of today's society. From the daily lives of residents to international transportation, the limited non-renewable energy resources on the earth are being exhausted. With increasing world energy demand and the shortage of fossil fuels, solar energy has become a key technology to solve energy problems. Compared with the serious pollution caused by fossil fuels, solar energy is clean and free. Nowadays, countries around the world are rapidly developing solar energy technology to alleviate the crisis caused by energy shortages. As a major oil producer and exporter, the United Arab Emirates (UAE) attached great importance to develop and utilize solar energy. The directed project investigated the feasibility and sustainability of developing solar energy in the UAE. The unique geographical location of the UAE gives it an absolute advantage in solar energy harvesting. However, the environment in the desert also affects the utilization of solar panels to a certain extent. The research performed data analysis on solar radiation and environmental factors to discuss the development prospects of solar energy in the UAE. Although the research has existing limitations, the strategic goal of sustainable development of solar energy never changes. Based on data and cost-effectiveness analysis, the directed research made recommendations to accept or decline the project.

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Teleke, Sercan. "Control methods for energy storage for dispatching intermittent renewable energy sources." 2009. http://www.lib.ncsu.edu/theses/available/etd-11022009-151719/unrestricted/etd.pdf.

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Luo, Yu-Qiao, and 羅宇喬. "The Optimization of Capacity of Energy Storage System in Microgridwith Renewable Energies." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/45092853933509614582.

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碩士 中原大學 電機工程研究所 102 Due to theproblem of running out fuel and global warming is getting worse and worse. Countries around the world began to pay attention to develop renewable energy to solve the rising energy costs and global climate changes. Based on the instability of renewable energy, the Technologies of smart grid and microgrid are being developed around the world. The research and construction of microgrid have been booming. 　　Microgrid which consists of loads, energy storages and distributed generations can operate under Independent operation, grid connected or islanding mode through proper control methodologies and communication technologies. Microgrid can reduce transmission losses, enhance the reliability and power quality of customer, and increase the penetration of renewable energy. 　　The optimization of capacity of energy storage system in microgrid is one of its research and planning. Although an ideal and cost-effective method is yet to see at present, however, there are numerous literatures have explored. 　　This thesis is focused on optimization of capacity of energy storage system in microgrid. A mathematical model is designed. According to the data of INER(Institute of Nuclear Energy Research),calculate the optimization of capacity of energy storage system in microgrid under Independent operation, grid connected or islanding mode. Furthermore, this algorithm is explored to the different situation in the future.

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Sundararagavan, Sandhya. "Characteristics of Electricity Storage Technologies for Maintaining Reliability of Grid with High Amounts of Intermittent Energy." 2010. https://scholarworks.umass.edu/theses/489.

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For the grid to be stable, the supply of power must equal the demands of the consumer at every moment during the day. The unpredictable intermittent nature of wind results in inconsistent power generation. Energy storage technologies coupled with a wind farm can not only provide power during fluctuations but also maintain a stable and reliable grid. The objective of the thesis is to perform a comprehensive analysis of different types of energy storage technologies that can be coupled with a wind farm. The analysis is performed on the basis of multiple characteristics which affect their viability. We identified key characteristics for a range of storage technologies, including lead-acid, sodium-sulphur, nickel cadmium, lithium-ion, superconducting magnetic energy storage, electrochemical capacitors, flywheels, flow batteries, pumped hydro and compressed air energy storage systems. We performed a comparison study to analyze trade-offs and assessed potential improvement areas that will make them more competitive in the electric power industry. We suggested viable energy storage systems that could be better and suitable for different applications for an electric grid integrated with a wind farm.

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Tesis sobre el tema "Storage of intermittent energies"

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