Cooking is an integral part of each and every human being as food is one of the basic necessities for living. Commonly used sources of energy for cooking are firewood, crop residue, cow dung, kerosene, electricity, liquefied petroleum gas(LPG), biogas etc. Half of the world’s population is exposed to indoor air pollution, mainly the result of burning solid fuels for cooking and heating. Wood cut for cooking purpose contributes tothe16 million hectares(above4% of total area of India) of forest destroyed annually. The World Health Organization(WHO) reports that in 23 countries 10% of deaths are due to just two environmental risk factors: unsafe water, including poor sanitation and hygiene; and indoor air pollution due to solid fuel usage for cooking. In under-developed countries, women have to walk 2kms on average and spend significant amount of time for collecting the firewood for cooking. The cooking energy demand in rural areas of developing countries is largely met with bio-fuels such as fuel wood, charcoal, agricultural residues and dung cakes, whereas LPG or electricity is predominantly used in urban areas. India has abandon amount of solar energy in most of the regions making it most ideal place for harvesting solar energy. With almost 300 sunny days each year, one can confidently relay on this source of energy. India’s geographical location is in such a way that theoretically it receives 5x1015 kWh/ year of solar energy. Solar cooking is the simplest, safest, environmental friendly and most convenient way to cook. It is a blessing for those who cook using firewood or cow dung, who walk for miles to collect wood, who suffer from indoor air pollution. Hence solar cooking is going to play major role in solving future energy problem. Solar based cooking has never been a strong contender in the commercial market or even close to being a preferred method of cooking. They have been relegated to demonstration appliances to show case the solar based concepts. In this mode, cooking is no longer a time independent activity that can be performed at any time of day. One is forced to cook only at certain times when there is sufficient insolation. The geography of the cooking activity also shifts away from the kitchen. The kitchen is no longer the hearth of the home as the actual cooking activity shifts to the roof tops or high insolation platforms. This further adds to the inconvenience apart from being unable to cook at night or during cloudy conditions or during most of the winter days. Another issue of significant inconvenience is the general social structure in most families of the developing countries wherein the cooking activity is carried out by the senior ladies of the home. They are generally not athletic enough to be moving to and from the kitchen and the roof top to carry out the cooking exercise. As the solar cookers are enclosed spaces, interactive cooking is not possible let alone having any control on the rate of cooking. These are some of the more significant issues in the social psyche that has abundantly impeded the acceptance of solar thermal based cooking appliances. These issues and problems are in fact the motivating factors for this thesis. Based on these motivating factors, this thesis aims to propose solutions keeping the following points as the major constraints. cooking should be performed in the kitchen. one should be able to perform the cooking activity independent of the time of day or insolation. the cooking activity should be interactive the time taken for cooking should be comparable with the conventional methods in vogue. there should be a reduction in the use of conventional energy. Using the constraints and the motivating factors discussed above as the central theme, this thesis proposes a method to transfer solar thermal energy to the kitchen and act as a supplement to the conventional source of energy like the LPG or other sources that are traditionally being used in the households. The method proposed is in fact a hybrid scenario wherein the solar thermal is used to supplement the traditional source. Solar photovoltaic cells are also used to power the electronics and apparatus proposed in this thesis. This thesis addresses in detail the issues in analysis, modeling, designing and fabrication of the proposed hybrid solar cooking topology. The main goal of the proposed system is to transfer heat from sun to the cooking load that is located in the kitchen. The topology includes an additional feature for storing the energy in a buffer. The heat is first transferred from the solar thermal collector to a heat storage tank(that acts as the buffer) by circulating the heat transfer fluid at a specific flow rate that is controlled by a pump. The stored heat energy that is collected in the buffer is directed into the kitchen by circulating the heat transfer fluid into the heat exchanger, located in the kitchen. This is accomplished by controlling the flow rate using another pump. The solar thermal collector raises the temperature of the thermic fluid. The collector can be of a concentrating type in order to attain high temperatures for cooking. Concentrating collector like linear parabolic collector or parabolic dish collector is used to convert solar energy into heat energy. Absorption of energy from the incident solar insolation is optimized by varying the flow rate of circulating thermic fluid using a pump. This pump is energized from a set of photovoltaic panels(PV cell) which convert solar energy into electrical energy. The energy absorbed from the solar thermal collector is stored in a buffer tank which is thermally insulated. Whenever cooking has to be carried out, the high temperature fluid from the buffer tank is circulated through a heat exchanger that is located in the kitchen. The rate of cooking can be varied by controlling both the flow rate of fluid from the buffer tank to heat exchanger and also by controlling the amount of energy drawn from the auxiliary source. If the available stored energy is not sufficient, the auxiliary source of energy is used for cooking in order to ensure that cooking is in-dependent of time and solar insolation. In the proposed hybrid solar cooking system, the thesis addresses the issues involved in optimization of energy extracted from sun to storage tank and its subsequent transfer from the storage tank to the load. The flow rate at which maximum energy is extracted from sun depends on many parameters. Solar insolation is one of the predominant parameters that affect the optimum flow rate. Insolation at any location varies with time on a daily basis (diurnal variations) and also with day on a yearly basis(seasonal variation). This implies that the flow rate of the fluid has to be varied appropriately to maximize the energy absorbed from sun. In the proposed system, flow rate control plays a very significant role in maximizing the energy transfer from the collector to the load. The flow rate of the thermic fluid in the proposed system is very small on the order of 0.02kg/s. It is very difficult to sense such low flows without disrupting the operating point of the system. Though there are many techniques to measure very low flow rates, they invariably disrupt the system in which flow rate has to be measured. Further, the low flow sensors are far too expensive to be included in the system. A reliable, accurate and inexpensive flow measuring technique has been proposed in this thesis which is non-disruptive and uses a null-deflection technique. The proposed measuring method compensates the pressure drop across the flow meter using a compensating pump. The analysis, modeling, design and fabrication of this novel flow meter are addressed. The design and implementation of different subsystems that involves the selection and design of solar concentrating collector and tracking are explained. Finally, it is essential to know the economic viability of the proposed system that is designed and implemented. To understand the economics, the life cycle cost analysis of the proposed system is presented in this thesis. The major contributions of this thesis are: Energy transport: Major challenge in energy transport is to bring heat energy obtained from the sun to the kitchen for cooking. Energy transferred from solar insolation to the cooking load has to be optimized to maximize the overall efficiency. This can be split in to two parts,(a) optimizing efficiency of energy transferred from the collect or to the energy buffer tank,(b) optimizing efficiency of energy transferred from the buffer tank to the load. The optimization is performed by means of a maximum power point tracking(MPPT) algorithm for a specific performance index. Modeling of the cooking system: There are several domains that exist in the solar cooking system such as electrical domain, thermal domain, and hydraulic domain. The analysis of power/energy flow across all these domains presents a challenging task in developing a model of the hybrid cooking system. A bond graph modeling approach is used for developing the mathematical model of the proposed hybrid cooking system. The power/energy flow across different domains can be seamlessly integrated using the bond graph modeling approach. In this approach, the various physical variables in the multi-domain environment are uniformly de-fined as generalized power variables such as effort and flow. The fundamental principle of conservation of power/energy issued in describing the flow of power/energy across different domains and thus constructing the dynamic model of the cooking system. This model is validated through experimentation and simulation. Flow measurement: A novel method of low fluid mass flow measurement by compensating the pressure drop across the ends of measuring unit using a compensating pump has been proposed. The pressure drop due to flow is balanced by feedback control loop. This is a null-deflection type of measurement. As insertion of such a measuring unit does not affect the functioning of the systems, this is also a non-disruptive flow measurement method. This allows the measurement of very low flow rate at very low resolution. Implementation and design of such a unit are discussed. The system is modeled using bond graph technique and then simulated. The flow meter is fabricated and the model is experimentally validated. Design Toolbox: Design of hybrid cooking system involves design of multi domain systems. The design becomes much more complex if the energy source to operate the system is hybrid solar based. The energy budget has to be evaluated considering the worst case conditions for the availability of the solar energy. The design toolbox helps in assessing the user requirement and help designing the cooking system to fulfill the user requirement. A detailed toolbox is proposed to be developed that can be used in designing/selecting sub-systems like collector, concentrator, tracking system, buffer tank, heat exchanger, PV panel, batteries etc. The toolbox can also be used for performing life cycle costing.

This study aimed at evaluating and demonstrating the feasibility of using Concentrated Solar Thermal technology combined with biomass energy technology as a hybrid renewable energy system to supply the process heat requirements in small scale industries in Sri Lanka. Particularly, the focus was to apply the concept to the expanding hotel industry, for covering the thermal energy demand of a medium scale hotel. Solar modules utilize the rooftop area of the building to a valuable application. Linear Fresnel type of solar concentrator is selected considering the requirement of the application and the simplicity of fabrication and installation compared to other technologies. Subsequently, a wood-fired boiler is deployed as the steam generator as well as the balancing power source to recover the effects due to the seasonal variations in solar energy. Bioenergy, so far being the largest primary energy supply in the country, has a good potential for further growth in industrial applications like small hotels.  When a hotel with about 200-guests capacity and annual average occupancy of 65% is considered, the total annual CO2 saving is accounted as 207 tons compared with an entirely fossil fuel (diesel) fired boiler system. The annual operational cost saving is around $ 40,000 and the simple payback period is within 3-4 years. The proposed hybrid system can generate additional 26 employment opportunities in the proximity of the site location area.   This solar-biomass hybrid concept mitigates the weaknesses associated with these renewable technologies when employed separately. The system has been designed in such a way that the total heat demand of hot water and process steam supply is managed by renewable energy alone. It is thus a self-sustainable, non-conventional, renewable energy system. This concept can be stretched to other critical medium temperature applications like for example absorption refrigeration. The system is applicable to many other industries in the country where space requirement is available, solar irradiance is rich and a solid biomass supply is assured.

Industrin står för 32% av den globala energianvändningen och majoriteten av industrins utsläpp sker vid förbränning av fossila bränslen för värmeanvändning. Hälften av industrins värmeanvändning uppskattas vara i temperaturer upp till 400 °C vilket är lämpligt för värme från solfångare.Klädesindustrin står för 10% av de globala växthusgasutsläppen och majoriteten av de utsläppen sker vid textilproduktion och flera av textilindustrins processer är i temperaturintervall som kan använda värme från solfångare likt Absolicons T160.Data från energianvändning hos textilfabriker har samlats in och beräkningar på energianvändning och utsläpp har gjorts för erhållna data. Solfångarnas energiberäkningar har gjorts med hjälp av simuleringar från Absolicon applikation Field Simulator. En 3-stegs plan gjordes för 2 stora textilfabriker i Indien som visar hur de skulle kunna eliminera sina utsläpp från energianvändning.Kartläggningen visar att textilindustrin till stor del använder fossila bränslen och de 5 största textilfabrikerna i denna rapport visar en energifördelning mellan värme och el på 85% respektive 15%. Utsläppen per producerad massa varor i kg för de 5 fabrikerna uppskattas vara i snitt 6,1 kgCO2e vilket motsvarar en förbränning av 2,1 kg brunkol.De två stora textilfabriker i Indien samlade utsläpp från energianvändning redovisas vara 686 ktCO2e. Värmeanvändningen i fabrikerna sänks i 3-stegsplanen med 17% och fossila bränslen ersätts med värme från solfångare och biomassa. För att täcka 68% av det nya värmebehovet med värme från solfångare så behövs det solfångarfält med en termisk effekt på cirka 400 MW och en yta på cirka 1,3 km2. De resterande 32% av värmebehovet ska komma från förbränning av cirka 100 000 ton biomassa per år.Industrin har möjlighet att sänka stora delar av sina utsläpp genom att ersätta fossila bränslen i värmeanvändningen med till exempel värme från solfångare och biomassa. För att täcka stora delar av värmeanvändningen med solfångarfält behövs lediga ytor runt om och på fabrikerna. Fossila bränslen har i dagsläget ett lågt pris i förhållande till dess utsläpp och tillämpning av globala utsläppsrätter eller skatter bör appliceras för att påskynda omställningen till utsläppsfri energi och lägre utsläpp. / The industry sector accounts for 32% of the global energy usage where the majority of the energy is being used as heat. Most of the heat is generated by burning fossil fuels which leads to heat use being the largest source of emissions in the sector. About half of energy used as in the industries are in temperatures up to 400 °C which is suitable for heat provided by solar collectors.The apparel industry accounts for 10% of the global carbon emissions and multiple of the industry processes used in textile production are in temperature ranges reachable with solar collectors such as Absolicons T160.Energy data was collected from textile factories and calculations of energy usage and emissions was made. The calculations for solar collectors was made with Absolicons web application Field Simulator. A 3-step plan was created to demonstrate how two textile factories in India could reach zero CO2 emissions.The analysis shows that the textile industry’s majority of energy is being used from fossil fuels to generate heat where the 5 largest factories in this report average energy is 85% as heat and 15% as electricity. The emissions per produced mass of goods in kg is an average of 6,1 kgCO2e at these 5 factories which is comparable to burning 2,1 kg of black coal.The two large textile factories combined emissions from energy usage is reported to be 686 ktCO2e. In the 3-step plan the heat usage is reduced by 17% and heat from fossil fuels are replaced by heat from solar collectors and biomass. To cover 68% of the new energy demand it would require solar fields with a total thermal capacity of about 400 MW and an area of 1,3 km2. The remaining 32% of heat demand would be covered by burning 100 000 tonne of biomass per year.The conclusion is that he industry sector has a huge potential of reducing their emissions by replacing fossil fuels for generating thermal energy by thermal energy from e.g. solar collectors or biomass. It will require available spaces close to or on top of the factories to be able cover large portions of the heat demand with solar collectors. The current prices of energy from fossil fuels is low compared to their emissions and a global carbon market or taxes should be applied to accelerate the change to clean energy and lower emissions.

A preocupação energética tem impulsionado a humanidade a buscar alternativas sustentáveis de energia. Neste contexto, os edifícios de escritórios têm um papel importante, em especial, devido ao elevado consumo de energia dos sistemas de condicionamento de ar. Para esses sistemas, a possibilidade de utilização de energia solar é uma alternativa tecnicamente possível e interessante de ser considerada, principalmente porque, quando a carga térmica do edifício é mais elevada, a radiação solar também é mais elevada. Dentre os sistemas de condicionamento de ar solar, o sistema térmico - que associa coletores solares térmicos com chiller de absorção - é o mais disseminado, na atualidade. Entretanto, dependendo do caso, outras tecnologias podem ser vantajosas. Uma opção, por exemplo, no caso de edifícios de escritórios, é o sistema elétrico - que associa painéis fotovoltaicos ao chiller convencional de compressão de vapor. Neste trabalho, para um edifício de escritórios de 20 pavimentos e 1000 m2 por pavimento, na cidade de São Paulo, no Brasil, duas alternativas de ar condicionado solar tiveram seus desempenhos energéticos analisados: o sistema térmico - com coletores solares térmicos somente na cobertura e o sistema elétrico - com painéis FV somente nas superfícies opacas das fachadas. Para isso, com o software EnergyPlus do Departamento de Energia dos Estados Unidos obteve-se as carga térmica atuantes no edifício e com a aplicação do método de cálculo de consumo de energia dos sistemas de ar condicionado solar, proposto pelo Projeto SOLAIR da União Européia, adaptado para a realidade da pesquisa, obteve-se o desempenho energético dos sistemas. Os resultados mostraram que, para o edifício de 20 pavimentos, o sistema elétrico tem o melhor desempenho energético, economizando 28% e 71% da energia elétrica que consumiria um sistema de ar condicionado convencional, em um dia de verão e de inverno, respectivamente. O sistema térmico, ao contrário, apresentou um desempenho energético ruim para o edifício estudado, consumindo, por exemplo, em um dia de verão, cerca de 4 vezes mais energia elétrica do que um sistema de ar condicionado convencional. Constatouse que isso ocorreu, pois a área coletora limitada à cobertura foi insuficiente para atender a demanda do chiller de absorção, que passou a operar com frações solares baixas, da ordem de 50% e 20%, de pico, no dia de inverno e de verão, respectivamente. Assim, constatou-se que para que o sistema térmico apresente um desempenho energético satisfatório é preciso que o edifício não seja tão alto. De fato, os resultados mostraram que somente se o edifício tivesse no máximo 2 pavimentos, o sistema térmico teria um desempenho energético melhor do que um sistema convencional. No caso de ser aplicado ao edifício térreo de 1000m2 de área, por exemplo, esse sistema economizaria aproximadamente 65% da energia elétrica do sistema convencional. Por fim, constatou-se também que o desempenho energético do sistema térmico seria elevado com a otimização da área e da tecnologia de coletores solares, com o aprimoramento do sistema de aquecimento auxiliar e com a redução da carga térmica do edifício por meio de técnicas passivas de climatização. / Energy concern has driven human kind to seek sustainable energy alternatives. In this context, office buildings have an important role, especially due to the high energy consumption of air conditioning systems. For these systems, the possibility of using solar energy is technically feasible and interesting to be considered, mainly because generally when the building thermal load is higher, the solar radiation is also higher. Among solar airconditioning systems, the thermal system - which combines solar collectors with absorption chiller - is the most widespread, nowadays. However, depending on the case, other technologies may take advantage. One option, for example, in the case of office buildings, is the electrical system - which combines photovoltaic panels with conventional vapor compression chiller. In this work, an office building of 20 floors with 1,000 m2 floor area, in Sao Paulo, Brazil, two technologies of solar air conditioning had their performance analyzed: the thermal system - presenting solar thermal collectors only on the roof and the electrical system with PV panels only on the opaque surfaces of the facades. For this, the software EnergyPlus of the United States Department of Energy obtained the building thermal load and the with the solar air conditioning energy consumption calculating method proposed by SOLAIR project of the European Union and adapted to this work, energy performance of systems was obtained. The results showed that for this building, the electrical system had the best energy performance, saving 28% and 71% of electricity that would consume a conventional air conditioning system in a summer day and a winter day, respectively. The thermal system, in contrast, showed a poor energy performance, consuming, for example, on a summer day, about four times more electricity than a conventional air conditioning system. It was found that this occurred because the collectors area limited to the roof of the building was insufficient to meet the absorption chiller demand, causing low solar fractions in the operation, of around 50% and 20% peak, in a winter day and in a summer day, respectively. Thus, in order of provide a satisfactory energy performance, the thermal system requires that the building not to be so tall. In fact, the results showed that only if the building had up to two floors, the system would perform better than a conventional system. In case of be installed in a building with the ground floor only, and floor area of 1000m2, for example, this system would save about 65% of the electricity comparing to a conventional system. Finally, it was found that this energy performance would be elevated as well with the optimization of solar collectors area and technology, with auxiliary heating system improvement and with the reduction of thermal load of the building by means of passive air conditioning techniques.

Ces travaux consistent en l’étude expérimentale et numérique des performances énergétiques d’un prototype de micro-cogénération solaire. L’installation, située sur le campus de l’Université de la Rochelle, fonctionne grâce au couplage d’un champ de capteur solaire cylindro-parabolique de 46,5 m² avec un moteur à vapeur à piston non lubrifié fonctionnant selon le cycle thermodynamique de Hirn. Le système de suivi solaire s’effectue selon deux axes et l’eau est directement évaporée au sein de l’absorbeur des capteurs cylindro-paraboliques. La génération d’électricité est assurée par une génératrice et la récupération des chaleurs fatales doit permettre d’assurer les besoins en chauffage et eau chaude sanitaire d’un bâtiment. La première partie de ces travaux présente les essais réalisés. L’objectif est de réaliser des essais complémentaires pour caractériser le concentrateur solaire, d’étudier les conditions de surchauffe de la vapeur, ainsi que le fonctionnement de l’installation complète en hiver. Ce travail a permis le développement de modèles pour le capteur cylindro-paraboliques, les essais en régime surchauffé ont montré la nécessité d’un appoint pour le fonctionnement d’une telle installation tandis que les essais avec moteur présentent des productions compatibles avec les consommations en électricité et chaleur d’un bâtiment résidentiel. La seconde partie concerne la modélisation des éléments constituant le micro-cogénérateur ainsi que l’intégration de cette installation au bâtiment à l’aide d’un logiciel de simulation thermique dynamique (TRNSYS©). Cette étude propose deux options d’intégration selon le positionnement de l’appoint de chaleur. Pour les deux configurations, des bilans hebdomadaires et annuels sont présentés permettant de discuter les avantages/inconvénients de chaque disposition. Il apparaît que le positionnement de l’appoint sur le circuit primaire permet de piloter la production électrique. L’ajout de l’appoint sur la distribution semble plus facilement réalisable mais empêche le contrôle de la production électrique. / This work consists of the experimental and numerical study of the energy performance of a prototype of solar micro-cogeneration. The facility, located on the campus of the University of La Rochelle, operates by coupling a 46.5 m² parabolic trough solar collector field with an oil-free piston steam engine operating according to the Hirn thermodynamic cycle. The solar tracking system is carried out in two axes and the water is evaporated directly into the absorber of the parabolic trough collectors. Electricity generation is provided by a generator and the recovery of fatal heat must make it possible to meet the heating and domestic hot water needs of a building. The first part of this work presents the tests performed. The objective is to carry out additional tests to characterize the solar concentrator, to study the conditions of steam overheating, as well as the operation of the complete installation in winter. This work has allowed the development of models for the parabolic trough sensor, the tests in overheated mode have shown the need for an extra charge for the operation of such an installation while the tests with motor present productions compatible with the electricity and heat consumption of a residential building. The second part concerns the modelling of the elements constituting the micro-cogenerator as well as the integration of this installation into the building using dynamic thermal simulation software (TRNSYS©). This study proposes two integration options depending on the positioning of the auxiliary heater. For both configurations, weekly and annual reviews are presented to discuss the advantages/disadvantages of each provision. It appears that the positioning of the auxiliary on the primary circuit makes it possible to control the electrical production. The addition of back-up boiler on the distribution seems more easily achievable but prevents the control of power generation.

Thermal energy storage (TES), the storage of heat or cooling, is a cost-effective energy storage technology that can greatly enhance the performance of the energy systems with which it interacts. TES acts as a buffer between transient supply and demand of energy. In solar thermal systems, TES enables the power output of the plant to be effectively regulated, despite fluctuating solar irradiance. In district energy systems, TES can be used to shift loads, allowing the system to avoid or take advantage of peak energy prices. The benefit of TES, however, can be significantly enhanced by dynamically optimizing the complete energy system. The ability of TES to shift loads gives the system newfound degrees of freedom which can be exploited to yield optimal performance. In the hybrid solar thermal/fossil fuel system explored in this work, the use of TES enables the system to extract nearly 50% more solar energy when the system is optimized. This requires relaxing some constraints, such as fixed temperature and power control, and dynamically optimizing the over a one-day time horizon. In a district cooling system, TES can help equipment to run more efficiently, by shifting cooling loads, not only between chillers, but temporally, allowing the system to take advantage of the most efficient times for running this equipment. This work also highlights the use of TES in a district energy system, where heat, cooling and electrical power are generated from central locations. Shifting the cooling load frees up electrical generation capacity, which is used to sell power to the grid at peak prices. The combination of optimization, TES, and participation in the electricity market yields a 16% cost savings. The problems encountered in this work require modeling a diverse range of systems including the TES, the solar power plant, boilers, gas and steam turbines, heat recovery equipment, chillers, and pumps. These problems also require novel solution methods that are efficient and effective at obtaining workable solutions. A simultaneous solution method is used for optimizing the solar power plant, while a static/dynamic decoupling method is used for the district energy system. / text

Οι ανανεώσιμες πηγές ενέργειας (ΑΠΕ), όπως η ηλιακή και αιολική ενέργεια μπορούν να προσφέρουν εναλλακτικούς τρόπους παραγωγής ενέργειας. Κάθε μορφή ΑΠΕ έχει τις δικές της ιδιομορφίες και μπορούν να εφαρμοστούν είτε σε μεγάλες εγκαταστάσεις παραγωγής ηλεκτρικής και θερμικής ενέργειας είτε σε μικρότερες μονάδες όπως στα κτίρια. Ενδιαφέρον παρουσιάζει η συνδυασμένη αξιοποίηση των παραπάνω ενεργειακών πηγών, ιδίως για την κάλυψη των ηλεκτρικών και θερμικών αναγκών των κτιρίων. Αντικείμενο της διπλωματικής αυτής εργασίας είναι η μελέτη ενός συστήματος αποτελούμενο από μικρή ανεμογεννήτρια, φωτοβολταϊκά πλαίσια και θερμικό ηλιακό συλλέκτη. Αρχικά γίνεται αναφορά στα επιμέρους συστήματα ΑΠΕ από τα οποία αποτελείται η εγκατάσταση. Στη συνέχεια, αναλύονται τα μετεωρολογικά δεδομένα της περιοχής και ακολουθεί η ενεργειακή μελέτη της συμπεριφοράς του υβριδικού συστήματος. Το κύριο θέμα που εξετάζεται είναι η παροχή ηλεκτρικής ενέργειας για θέρμανση του νερού σε περιπτώσεις που υπάρχει πλεόνασμα ηλεκτρικής ενέργειας. Επίσης αναλύεται η προοπτική συνδυασμού υβριδικών/φωτοβολταϊκών συλλεκτών με Α/Γ. Τέλος παρατίθενται τα συμπεράσματα και οι εκτιμήσεις σχετικά με τη συμπεριφορά του υβριδικού συστήματος στις μεταβολές της ταχύτητας του ανέμου και της ηλιακής ακτινοβολίας σε ημερήσια και ετήσια βάση. / The renewable energy sources (RES) like solar and wind energy can offer an alternative solution to produce power. Each form of RES, has its own specifications and they can applied in big installations of production electric and thermal energy or in smaller units as the buildings. This thesis investigates the performance of a system consist of a small wind turbine, solar photovoltaic modules and solar thermal collector. In the beginning, the design and components of installation is presented. Then, the measured data are used to analyzed the meteorological condition of test site and evaluate the performance of the hybrid system. The main concept, regarding the energy use of electrical to heat water in case that there is surplus of it, is presented. Finally conclusions and considerations about the behavior of hybrid system from the daily and yearly variation of wind speed and solar radiation are included.

Les systèmes de stockage de chaleur par sorption (SSCS) ouvrent de nouvelles perspectives dans l'exploitation de l'énergie solaire pour le chauffage des bâtiments résidentiels. En effet, ces systèmes sont très prometteurs dans la mesure où ils permettent un stockage de chaleur sur de longues périodes (le stockage est réalisé sous forme de potentiel chimique) et offrent des densités énergétiques importantes (jusqu'à 230 kWh/m3 de matériau en moyenne) en comparaison aux systèmes classiques comme le stockage par chaleur sensible (qui, pour le cas de l'eau, dispose d'une densité énergétique moyenne d'environ 81 kWh/m3 de matériau pour une variation de 70°C) et le stockage par chaleur latente (qui atteint des densités énergétiques de 90 kWh/m3 de matériau).La présente thèse vise à étudier les performances d'un système de stockage de chaleur par sorption à base de zéolithe 13X intégré à un bâtiment type basse consommation. Des modèles mathématiques de transferts couplés de masse et de chaleur des différents composants du système sont développés et validés par le biais de l'expérimentation. La simulation numérique dynamique, comme outil de dimensionnement, permet, à partir des résultats d'analyses de sensibilité paramétrique sur les différents composants du système, l'étude de son fonctionnement et les critères de sa faisabilité. / Sorption heat storage systems (SHSS) open new perspectives for solar heating of residential buildings. These systems allow long term heat storage (storage is done in the form of chemical potential) and offer high energy densities (up to 230 kWh/m3 of material on average) compared to conventional heat storage systems such as sensible heat storage (which, for the case of water, has an average energy density of approximately 81 kWh/m3 of material for a temperature change of 70 °C) and latent heat storage (nearly reaching energy densities of 90 kWh/m3 of material on average).This thesis aims to study the performance of a sorption solar heat storage system on zeolite 13X, integrated to low-energy building. Mathematical models of coupled heat and mass transfer of various components of the system are developed and validated through experimentation. Numerical dynamic simulations allow to study the functioning of the SHSS in specific conditions, and its design with the results from the parametric sensitivity analysis on its components.

A preocupação energética tem impulsionado a humanidade a buscar alternativas sustentáveis de energia. Neste contexto, os edifícios de escritórios têm um papel importante, em especial, devido ao elevado consumo de energia dos sistemas de condicionamento de ar. Para esses sistemas, a possibilidade de utilização de energia solar é uma alternativa tecnicamente possível e interessante de ser considerada, principalmente porque, quando a carga térmica do edifício é mais elevada, a radiação solar também é mais elevada. Dentre os sistemas de condicionamento de ar solar, o sistema térmico - que associa coletores solares térmicos com chiller de absorção - é o mais disseminado, na atualidade. Entretanto, dependendo do caso, outras tecnologias podem ser vantajosas. Uma opção, por exemplo, no caso de edifícios de escritórios, é o sistema elétrico - que associa painéis fotovoltaicos ao chiller convencional de compressão de vapor. Neste trabalho, para um edifício de escritórios de 20 pavimentos e 1000 m2 por pavimento, na cidade de São Paulo, no Brasil, duas alternativas de ar condicionado solar tiveram seus desempenhos energéticos analisados: o sistema térmico - com coletores solares térmicos somente na cobertura e o sistema elétrico - com painéis FV somente nas superfícies opacas das fachadas. Para isso, com o software EnergyPlus do Departamento de Energia dos Estados Unidos obteve-se as carga térmica atuantes no edifício e com a aplicação do método de cálculo de consumo de energia dos sistemas de ar condicionado solar, proposto pelo Projeto SOLAIR da União Européia, adaptado para a realidade da pesquisa, obteve-se o desempenho energético dos sistemas. Os resultados mostraram que, para o edifício de 20 pavimentos, o sistema elétrico tem o melhor desempenho energético, economizando 28% e 71% da energia elétrica que consumiria um sistema de ar condicionado convencional, em um dia de verão e de inverno, respectivamente. O sistema térmico, ao contrário, apresentou um desempenho energético ruim para o edifício estudado, consumindo, por exemplo, em um dia de verão, cerca de 4 vezes mais energia elétrica do que um sistema de ar condicionado convencional. Constatouse que isso ocorreu, pois a área coletora limitada à cobertura foi insuficiente para atender a demanda do chiller de absorção, que passou a operar com frações solares baixas, da ordem de 50% e 20%, de pico, no dia de inverno e de verão, respectivamente. Assim, constatou-se que para que o sistema térmico apresente um desempenho energético satisfatório é preciso que o edifício não seja tão alto. De fato, os resultados mostraram que somente se o edifício tivesse no máximo 2 pavimentos, o sistema térmico teria um desempenho energético melhor do que um sistema convencional. No caso de ser aplicado ao edifício térreo de 1000m2 de área, por exemplo, esse sistema economizaria aproximadamente 65% da energia elétrica do sistema convencional. Por fim, constatou-se também que o desempenho energético do sistema térmico seria elevado com a otimização da área e da tecnologia de coletores solares, com o aprimoramento do sistema de aquecimento auxiliar e com a redução da carga térmica do edifício por meio de técnicas passivas de climatização. / Energy concern has driven human kind to seek sustainable energy alternatives. In this context, office buildings have an important role, especially due to the high energy consumption of air conditioning systems. For these systems, the possibility of using solar energy is technically feasible and interesting to be considered, mainly because generally when the building thermal load is higher, the solar radiation is also higher. Among solar airconditioning systems, the thermal system - which combines solar collectors with absorption chiller - is the most widespread, nowadays. However, depending on the case, other technologies may take advantage. One option, for example, in the case of office buildings, is the electrical system - which combines photovoltaic panels with conventional vapor compression chiller. In this work, an office building of 20 floors with 1,000 m2 floor area, in Sao Paulo, Brazil, two technologies of solar air conditioning had their performance analyzed: the thermal system - presenting solar thermal collectors only on the roof and the electrical system with PV panels only on the opaque surfaces of the facades. For this, the software EnergyPlus of the United States Department of Energy obtained the building thermal load and the with the solar air conditioning energy consumption calculating method proposed by SOLAIR project of the European Union and adapted to this work, energy performance of systems was obtained. The results showed that for this building, the electrical system had the best energy performance, saving 28% and 71% of electricity that would consume a conventional air conditioning system in a summer day and a winter day, respectively. The thermal system, in contrast, showed a poor energy performance, consuming, for example, on a summer day, about four times more electricity than a conventional air conditioning system. It was found that this occurred because the collectors area limited to the roof of the building was insufficient to meet the absorption chiller demand, causing low solar fractions in the operation, of around 50% and 20% peak, in a winter day and in a summer day, respectively. Thus, in order of provide a satisfactory energy performance, the thermal system requires that the building not to be so tall. In fact, the results showed that only if the building had up to two floors, the system would perform better than a conventional system. In case of be installed in a building with the ground floor only, and floor area of 1000m2, for example, this system would save about 65% of the electricity comparing to a conventional system. Finally, it was found that this energy performance would be elevated as well with the optimization of solar collectors area and technology, with auxiliary heating system improvement and with the reduction of thermal load of the building by means of passive air conditioning techniques.

The theme of this master's thesis is the elaborating of an energy audit according to the valid legislation in the Czech Republic a five-storey apartment building. The master's thesis consists of three main parts. Theoretical, Computional and Energy Audit. The theoretical part focuses on the theme of solar thermal collectors. In the calculation part, the energy consumption of the assessed object is analyzed in both the initial and the new state. The energy audit is drawn up in accordance the Decree number 480/2012 Sb. in the current version.