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Riverola, Lacasta Alberto. "Dielectric solar concentrators for building integration of hybrid photovoltaic-thermal systems." Doctoral thesis, Universitat de Lleida, 2018. http://hdl.handle.net/10803/663116.
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L'objectiu de la present tesi és desenvolupar, optimitzar, fabricar i caracteritzar experimentalment un sistema solar de baixa concentració, fotovoltaic i tèrmic, per a integració arquitectònica en façanes on les cèl·lules estan submergides en un líquid dielèctric. L'objectiu està alineat cap al compliment de la directiva sobre eficiència energètica en edificis establerta per la Comissió Europea.
Els sistemes solars fotovoltaics i tèrmics per integració en edificis permeten la cogeneració d'electricitat i calor al mateix edifici amb unes eficiències globals al voltant del 70% i utilitzen una menor superfície comparat amb un col·lector tèrmic i un mòdul fotovoltaic independents. D'altra banda, els sistemes de baixa concentració permeten reduir costos utilitzant cèl·lules solars estàndards, amb una àrea reduïda i seguiment en un sol eix. A més, la immersió de les cèl·lules en líquids dielèctrics comporta uns beneficis agregats com ara la reducció de les pèrdues de Fresnel i un millor control de la temperatura. La necessitat d'estudiar i desenvolupar aquests sistemes per a la seva integració en edificis ve donada per les qualitats prèviament descrites i per l’estudi de l'estat de l'art realitzat.
El disseny proposat està compost d'un xassís cilíndric i una cavitat interna per on circula el líquid dielèctric (aigua desionitzada o alcohol isopropílic) en el qual hi ha les cèl·lules submergides. Cada mòdul segueix l'altura solar rotant i està dissenyat per ser col·locat en files formant una matriu. L'aparença del conjunt és similar a la de les lames que es troben normalment en les finestres. S’ha implementat un moviment secundari que controla la distància vertical entre mòduls per evitar l’ombra entre ells mateixos i controla la il·luminació interior.
Per dur a terme un desenvolupament òptim, s'ha modelat la distribució espectral de la llum solar incident a la qual es veuen exposades les cèl·lules solars en condicions reals. S’ha dut a terme un anàlisis exhaustiu dels líquids dielèctrics susceptibles de complir amb els requeriments per a la present aplicació. S'ha modelat la absortivitat / emissivitat de les cèl·lules de silici comercials en un rang espectral que va des del ultraviolat fins a l'infraroig mitjà i s'ha validat experimentalment. A partir d'aquí, s’ha desenvolupat un algoritme de traçat de raigs que computa l'energia per optimitzar el disseny òptic del concentrador per posteriorment fabricar-lo i analitzar-lo mitjançant una simulació CFD. Fet que ens permet caracteritzar el sistema tèrmicament i òpticament. Finalment, s'ha realitzat una simulació energètica amb el sistema instal·lat a les finestres d'una casa estàndard per tal d'avaluar quines parts de les demandes energètiques de l'edifici és capaç de satisfer. Aquesta simulació s’ha dut a terme en tres localitzacions diferents.
El rendiment del sistema ha estat estudiat en llocs caracteritzats per hiverns suaus i altures solars no molt elevades, obtenint resultats satisfactoris cobrint una gran part de la demanda de climatització, d'aigua calenta sanitària i elèctrica.El objetivo de la presente tesis es desarrollar, optimizar, fabricar y caracterizar experimentalmente un sistema solar de baja concentración, fotovoltaico y térmico, para integración arquitectónica en fachadas donde las células están sumergidas en un líquido dieléctrico. Este objetivo está perfectamente alineado con el cumplimiento de la directiva sobre eficiencia energética en edificios establecida por la Comisión Europea. Los sistemas solares fotovoltaicos y térmicos para integración en edificios atesoran la cogeneración de electricidad y calor en el mismo edificio con unas eficiencias globales alrededor del 70% y utilizando una menor superficie que si incorporamos un colector térmico y un módulo fotovoltaico separados. Por otra parte, los sistemas de baja concentración permiten reducir costes utilizando células solares estándar, con un área reducida y seguimiento en un solo eje. Además, la inmersión de las células en líquidos dieléctricos conlleva unos beneficios agregados como son la reducción de las pérdidas de Fresnel y un mejor control de la temperatura. Del estado del arte realizado y las cualidades previamente descritas, se desprende la necesidad de estudiar y desarrollar estos sistemas para su integración en edificios. El diseño propuesto está compuesto de un chasis cilíndrico y una cavidad interna por donde circula el líquido dieléctrico (agua desionizada o alcohol isopropílico) en el cual están las células sumergidas. Cada módulo sigue la altura solar rotando y está diseñado para ser colocado en filas formando una matriz. De este modo, la apariencia del conjunto es similar a la de las lamas que se encuentran comúnmente en ventanas. Además, un movimiento secundario que regula la distancia vertical entre los módulos para evitar sombreo entre ellos mismos y controlar la iluminación interior, ha sido implementado. Para llevar a cabo un desarrollo óptimo, se ha modelado la distribución espectral de la luz solar incidente a la cual se ven expuestas las células solares en condiciones reales. Se ha realizado un análisis exhaustivo de los líquidos dieléctricos susceptibles de cumplir con los requerimientos para la presente aplicación. Se ha modelado la absortividad/emisividad de las células de silicio comerciales en un rango espectral que va desde el ultravioleta hasta el infrarrojo medio y se ha validado experimentalmente. A partir de aquí, se ha desarrollado un algoritmo de trazado de rayos para optimizar el diseño óptico del concentrador con el fin de posteriormente fabricarlo y analizarlo mediante una simulación CFD. Hecho que nos permite caracterizarlo ópticamente y térmicamente. Finalmente, se ha realizado una simulación energética con el sistema instalado sobre las ventanas de una casa estándar para evaluar que parte de las demandas energéticas del edificio es capaz de satisfacer. Esta simulación se ha realizado en tres localizaciones distintas. El rendimiento del sistema ha sido estudiado en lugares caracterizados por inviernos suaves y alturas solares no muy elevadas, cubriéndose una gran parte de las demandas de agua caliente sanitaria, eléctricas y de climatización.
The goal of this thesis is to develop, optimize, fabricate and experimentally test a low-concentrating photovoltaic thermal system (CPVT) for building façade integration where the cells are directly immersed in a dielectric liquid. The objective sought is perfectly aligned with the Energy Performance Building Directive established by the European Commission in terms of energy efficiency. Building-integrated PVT systems present an on-site cogeneration of electricity and heat with global efficiencies around 70% and lower space utilization compared to a separate thermal collector and PV module. On the other hand, low-concentrating systems improve the cost effectiveness by using standard cells, single axis-tracking and reduced cell areas. In addition, direct-immersion of solar cells in dielectric liquids brings associated benefits such as a reduction of Fresnel losses and a better temperature control. From the state-of-the-art performed and the previous facts, the need for further developing and studying these systems for building integration purposes was found. The proposed design is composed by a cylindrical chassis and an inner cavity filled with the circulating dielectric liquid (deionized water or isopropyl alcohol) in which the cells are immersed. The module tracks the solar height by rotation and it is designed to be placed in rows as an array so that the appearance is akin to ordinary window blinds. A secondary movement has been implemented to control the vertical distance between modules and to avoid shading between them while provide lighting control. For an appropriate development, the spectral distribution of the incident solar irradiance to which solar cells are exposed under real working conditions has been modelled. An in-depth analysis of suitable dielectric liquid candidates based on the required properties for this application has been performed. The absorptivity/emissivity of standard silicon solar cells has been modeled from the ultraviolet to the mid-infrared and validated by an experimental measurement. Then, a full ray-tracing algorithm was developed to optimize the concentrator optical design and the optimum collector was fabricated and analyzed by a CFD simulation to thermally characterize the system. Finally, an energetic simulation with the concentrators superimposed in front of the windows in a standard house aiming to partially cover the building demands has been performed for three locations. The system performance has been studied for locations with mild winters and latitudes not achieving very high solar heights with satisfactory solar fractions regarding domestic hot water, electrical and space heating and cooling demands.
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Aldubyan, Mohammad Hasan. "Thermo-Economic Study of Hybrid Photovoltaic-Thermal (PVT) Solar Collectors Combined with Borehole Thermal Energy Storage Systems." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1493243575479443.
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Saadon, Syamimi. "Modeling and simulation of a ventilated building integrated photovoltaic/thermal (BIPV/T) envelope." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0049.
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La demande d'énergie consommée par les habitants a connu une croissance significative au cours des 30 dernières années. Par conséquent, des actions sont menées en vue de développement des énergies renouvelables et en particulier de l'énergie solaire. De nombreuses solutions technologiques ont ensuite été proposées, telles que les capteurs solaires PV/T dont l'objectif est d'améliorer la performance des panneaux PV en récupérant l’énergie thermique qu’ils dissipent à l’aide d’un fluide caloporteur. Les recherches en vue de l'amélioration des productivités thermiques et électriques de ces composants ont conduit à l'intégration progressive à l’enveloppe des bâtiments afin d'améliorer leur surface de captation d’énergie solaire. Face à la problématique énergétique, les solutions envisagées dans le domaine du bâtiment s’orientent sur un mix énergétique favorisant la production locale ainsi que l’autoconsommation. Concernant l’électricité, les systèmes photovoltaïques intégrés au bâtiment (BIPV) représentent l’une des rares technologies capables de produire de l’électricité localement et sans émettre de gaz à effet de serre. Cependant, le niveau de température auquel fonctionnent ces composants et en particulier les composants cristallins, influence sensiblement leur efficacité ainsi que leur durée de vie. Ceci est donc d’autant plus vrai en configuration d’intégration. Ces deux constats mettent en lumière l’importance du refroidissement passif par convection naturelle de ces modules. Ce travail porte sur la simulation numérique d'une façade PV partiellement transparente et ventilée, conçu pour le rafraichissement en été (par convection naturelle) et pour la récupération de chaleur en hiver (par ventilation mécanique). Pour les deux configurations, l'air dans la cavité est chauffé par la transmission du rayonnement solaire à travers des surfaces vitrées, et par les échanges convectif et radiatif. Le système est simulé à l'aide d'un modèle multi-physique réduit adapté à une grande échelle dans des conditions réelles d'exploitation et développé pour l'environnement logiciel TRNSYS. La validation du modèle est ensuite présentée en utilisant des données expérimentales du projet RESSOURCES (ANR-PREBAT 2007). Cette étape a conduit, dans le troisième chapitre du calcul des besoins de chauffage et de refroidissement d'un bâtiment et l'évaluation de l'impact des variations climatiques sur les performances du système. Les résultats ont permis enfin d'effectuer une analyse énergétique et exergo-économiqueThe demand of energy consumed by human kind has been growing significantly over the past 30 years. Therefore, various actions are taken for the development of renewable energy and in particular solar energy. Many technological solutions have then been proposed, such as solar PV/T collectors whose objective is to improve the PV panels performance by recovering the heat lost with a heat removal fluid. The research for the improvement of the thermal and electrical productivities of these components has led to the gradual integration of the solar components into building in order to improve their absorbing area. Among technologies capable to produce electricity locally without con-tributing to greenhouse gas (GHG) releases is building integrated PV systems (BIPV). However, when exposed to intense solar radiation, the temperature of PV modules increases significantly, leading to a reduction in efficiency so that only about 14% of the incident radiation is converted into electrical energy. The high temperature also decreases the life of the modules, thereby making passive cooling of the PV components through natural convection a desirable and cost-effective means of overcoming both difficulties. A numerical model of heat transfer and fluid flow characteristics of natural convection of air is therefore undertaken so as to provide reliable information for the design of BIPV. A simplified numerical model is used to model the PVT collector so as to gain an understanding of the complex processes involved in cooling of integrated photovoltaic arrays in double-skin building surfaces. This work addresses the numerical simulation of a semi-transparent, ventilated PV façade designed for cooling in summer (by natural convection) and for heat recovery in winter (by mechanical ventilation). For both configurations, air in the cavity between the two building skins (photovoltaic façade and the primary building wall) is heated by transmission through transparent glazed sections, and by convective and radiative exchange. The system is simulated with the aid of a reduced-order multi-physics model adapted to a full scale arrangement operating under real conditions and developed for the TRNSYS software environment. Validation of the model and the subsequent simulation of a building-coupled system are then presented, which were undertaken using experimental data from the RESSOURCES project (ANR-PREBAT 2007). This step led, in the third chapter to the calculation of the heating and cooling needs of a simulated building and the investigation of impact of climatic variations on the system performance. The results have permitted finally to perform the exergy and exergoeconomic analysis
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Lai, Chi-Ming. "Development and thermal performance assessment of the opaque PV façades for subtropical climate region." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/204562.
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Ramadan, Khaled Mohamed. "Modelling and Experimental Characterization of Photovoltaic/Thermal Systems for Cooling and Heating of Buildings in different climate conditions." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/670914.
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La integración de sistemas de fotovoltaicos/térmicos (PV/T) y un eficiente aire acondicionado en los edificios permite el
suministro de calefacción, refrigeración y electricidad con una reducción de las emisiones de efecto invernadero. Las
configuraciones de integración de: a) sistemas fotovoltaicos (PV) con enfriadores eléctricos refrigerados por aire y
sistemas de bombas de calor aire-agua; b) sistemas fotovoltaicos/térmicos (PV/T) basados en aire con sistemas de
bomba de calor aire-agua; y c) Los sistemas fotovoltaicos/térmicos de baja concentración (LCPV/T) con enfriadores de
compresión y absorción tienen un gran potencial para aumentar la proporción de electricidad fotovoltaica in situ.
La flexibilidad de incorporar energía LCPV/T para la red bidireccional de baja temperatura en distritos urbanos reduce
las pérdidas térmicas y proporciona edificios de productores y consumidores (prosumidores). En comparación con la
configuración típica del enfriador de compresión integrado fotovoltaico, la configuración propuesta de LCPV/T junto
con los enfriadores de compresión y absorción reduce el período de recuperación en un 10-40% en el edificio de cajas
en El Cairo. Sustituir la conexión a la red de agua del campus por el uso de bomba de calor reversible reduce en un
15-30% el coste operativo de refrigeración y calefacción en el edificio de cajas en España.The integration of photovoltaic/thermal (PV/T) and efficient air conditioning systems into buildings allows the provision of heating, cooling and electricity with a reduction in greenhouse emissions. The integration configurations of: a) photovoltaic (PV) systems with air-cooled electric chillers and air-to-water heat pump (HP) systems; b) air-based PV/T systems with air-to-water HP systems; c) Low concentrated photovoltaic/thermal systems (LCPV/T) with compression and absorption chillers; and d) LCPV/T coupled with water-to-water HP have a great potential in boosting the share of onsite PV-electricity. The flexibility of incorporating LCPV/T energy for the bidirectional low temperature network in urban districts reduces thermal losses and provides producer and consumer (prosumer) buildings. In comparison to the typical configuration of PV integrated compression chiller, the proposed configuration of LCPV/T coupled with the compression and absorption chillers reduces the payback period by 10-40% in the case building in Cairo. Substituting the connection to the campus water network with the use of reversible
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Brogren, Maria. "Optical Efficiency of Low-Concentrating Solar Energy Systems with Parabolic Reflectors." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3988.
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SILENZI, FEDERICO. "DYNAMIC THERMAL ANALYSIS OF NEARLY ZERO EMISSION BUILDINGS WITH GEOTHERMAL AND SOLAR PLANTS." Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1002027.
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At the present day, the need for the reduction of energy consumption is one of the main issues, from the technical, economic and environmental point of view. Buildings are responsible for more than 40% of energy utilization in European countries in 2017 [1]. Thus, actions that increase building energy efficiency are mandatory. Some interventions on the envelope and the internal operating conditions are addressed to the reduction of the heating and cooling loads of the building (i.e. the energy needs). Others pertain directly to the plants that must be properly selected and sized considering, if possible, also the use of renewable energies.
In this framework, the present study is devoted to the analysis of energy-efficient buildings, with features aimed to reduce the loads and equipped with efficient plant solutions including innovative ground coupled water-to-water heat pumps and high efficiency air to air heat pump with energy recovery.
The first part of the study is devoted to the ground heat exchangers and in particular to the modeling of energy geopiles in which the geothermal heat exchangers are integrated into the foundations of the building. To correctly size a ground heat exchanger (HE) field, in terms of total length, the number of HE and spacing, the ground response is needed and is provided in terms of g–function. A new semi-analytical method is proposed, based on the spatial superposition of a basic analytical solution, namely the single point source solution. This method allows generating ground response function (g-functions) for shapes of the heat exchanger different from classical linear one, as for the case of helix. The method has been validated by comparison with literature analytical solutions and with FEM simulations with Comsol Multiphysics.
The second part of the research is devoted to developing a comprehensive model for dynamical energy simulations of a Nearly-Zero-Emission-Building. The model, developed with three different software (Sketch-Up, Openstudio and Energy Plus), represents the Smart Energy Building (SEB) located in the Savona Campus of the University of Genoa. The SEB is a very innovative building for both the envelope (ventilated facades) and the energy systems (i.e. geothermal heat pump and high efficiency air-to-air heat pump with energy recovery). Moreover, it has a complete monitoring system with numerous sensors that provide in real-time numerous thermal and electrical data (temperature, mass flow rates, electrical power, current, etc).
All the detailed features of the building have been analyzed: the geometry, the materials, and the internal operating conditions. The climatic conditions of the site where the building is located are considered through a proper weather file. That information allows evaluating, firstly, the heating and cooling loads, which means the energy needs of the building during winter and summer.
Then, the thermal plants have been introduced into the model, namely the ground coupled water-to-water heat pump and the air handler associated to a high efficiency air-to-air heat pump with energy recovery. For both the heat pumps, the performance (COP and EER) depends on the load and source-side fluid temperatures. This feature has been carefully implemented in the Energyplus model.
The main results from the simulations are zone temperatures and primary energy consumption from the heating and cooling plants. Finally, the PV modules located on the roof of the SEB have been included in the model. The PV field has been analyzed considering electrical power production, cell temperature and solar irradiance received.
The SEB is included in the complex and complete monitoring system of the Smart Polygeneration Microgrid of the Savona Campus The validation process of the model with real measurements from the SEB monitoring system would represent an important and original contribution of this study. Unfortunately, a complete analysis is not possible at the moment due to the unavailability of data series about the ventilation system. However, a preliminary comparison between model and measured data has been realized for the electrical production from the PV modules of the roof of the building. In particular, the EnergyPlus model has been updated by inserting a properly modified weather file with the measured values of outdoor air temperature and solar irradiance (global horizontal value). The calculation is done for two sample months (i.e. January and June 2018). The comparison shows a quite good agreement between simulated data trends and measured values, with a discrepancy at peak values. It is not clear if this disagreement is imputable to poor simulation parameter choice or errors in measures acquisition.
Future work will be aimed towards completing the validation of the model using the huge amount of data from the monitoring system. Moreover, the model will be used to study the SEB thermal flexibility to different control strategies.
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Böhme, Florén Simon. "Solel och solvärme ur LCC-perspektiv för ett passiv-flerbostadshus." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-162430.
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This master’s degree project concerns the combination of a multi dwelling passive house with solar energy for the generation of electricity and domestic hot water (DHW). Different alternatives with either solar thermal systems or photovoltaic (PV) systems are compared with two reference alternatives producing DHW from electricity or district heating. The economical comparison uses a life cycle cost (LCC) perspective based on the present value of expenditures for investment, energy and annual operating and maintenance. The energy yields from the solar energy systems were calculated by hand and with simulation software. Calculation and dimensioning of PV systems were carried out with a software called PVSYST. Solar thermal systems were calculated by hand and with the software Winsun Villa Education. Both softwares use hourly weather data for the calculations. The LCCs are lower for the two reference alternatives than for the solar energy alternatives. The reference alternative with district heating generates the lowest LCC. The alternatives with solar thermal energy replace more energy and have significantly lower LCCs than the PV alternatives. The study also shows the importance of using cheap and environmentally friendly backup energy for producing DHW. When aiming for a quantitative energy use target, the DHW-circulation losses ought to be taken into account as these can be extensive.
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Hrazdira, David. "Energetický audit." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372193.
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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.
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Abu, Qadourah Jenan [Verfasser], Christoph [Akademischer Betreuer] Nytsch-Geusen, Christoph [Gutachter] Nytsch-Geusen, and Christoph [Gutachter] Gengnagel. "Architectural integration of photovoltaic and solar thermal technologies in multi-family residential buildings in the Mediterranean area / Jenan Abu Qadourah ; Gutachter: Christoph Nytsch-Geusen, Christoph Gengnagel ; Betreuer: Christoph Nytsch-Geusen." Berlin : Universität der Künste Berlin, 2020. http://d-nb.info/1215340222/34.
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Ara, Paulo José Schiavon. "Desempenho de sistemas de condicionamento de ar com utilização de energia solar em edifícios de escritórios." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-01032011-135653/.
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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.
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Coventry, Joseph Sydney, and Joe Coventry@anu edu au. "A solar concentrating photovoltaic/thermal collector." The Australian National University. Faculty of Engineering and Information Technology, 2004. http://thesis.anu.edu.au./public/adt-ANU20041019.152046.
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This thesis discusses aspects of a novel solar concentrating photovoltaic / thermal (PV/T) collector that has been designed to produce both electricity and hot water. The motivation for the development of the Combined Heat and Power Solar (CHAPS) collector is twofold: in the short term, to produce photovoltaic power and solar hot water at a cost which is competitive with other renewable energy technologies, and in the longer term, at a cost which is lower than possible with current technologies. To the authors knowledge, the CHAPS collector is the first PV/T system using a reflective linear concentrator with a concentration ratio in the range 20-40x. The work contained in this thesis is a thorough study of all facets of the CHAPS collector, through a combination of theoretical and experimental investigation.
A theoretical discussion of the concept of energy value is presented, with the aim of developing methodologies that could be used in optimisation studies to compare the value of electrical and thermal energy. Three approaches are discussed; thermodynamic methods, using second law concepts of energy usefulness; economic valuation of the hot water and electricity through levelised energy costs; and environmental valuation, based on the greenhouse gas emissions associated with the generation of hot water and electricity. It is proposed that the value of electrical energy and thermal energy is best compared using a simple ratio.
Experimental measurement of the thermal and electrical efficiency of a CHAPS receiver was carried out for a range of operating temperatures and fluid flow rates. The effectiveness of internal fins incorporated to augment heat transfer was examined. The glass surface temperature was measured using an infrared camera, to assist in the calculation of thermal losses, and to help determine the extent of radiation absorbed in the cover materials. FEA analysis, using the software package Strand7, examines the conductive heat transfer within the receiver body to obtain a temperature profile under operating conditions.
Electrical efficiency is not only affected by temperature, but by non-uniformities in the radiation flux profile. Highly non-uniform illumination across the cells was found to reduce the efficiency by about 10% relative. The radiation flux profile longitudinal to the receivers was measured by a custom-built flux scanning device. The results show significant fluctuations in the flux profile and, at worst, the minimum flux intensity is as much as 27% lower than the median. A single cell with low flux intensity limits the current and performance of all cells in series, causing a significant drop in overall output. Therefore, a detailed understanding of the causes of flux non-uniformities is essential for the design of a single-axis tracking PV trough concentrator. Simulation of the flux profile was carried out using the ray tracing software Opticad, and good agreement was achieved between the simulated and measured results. The ray tracing allows the effect of the receiver supports, the gap between mirrors and the mirror shape imperfections to be examined individually.
A detailed analytical model simulating the CHAPS collector was developed in the TRNSYS simulation environment. The accuracy of the new component was tested against measured data, with acceptable results. A system model was created to demonstrate how sub components of the collector, such as the insulation thickness and the conductivity of the tape bonding the cells to the receiver, can be examined as part of a long term simulation.
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Coventry, Joseph Sydney. "A solar concentrating photovoltaic/thermal collector /." View thesis entry in Australian Digital Theses Program, 2004. http://thesis.anu.edu.au/public/adt-ANU20041019.152046/index.html.
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Williams, Kristen. "Solar integration : applying hybrid photovoltaic/thermal systems." Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/3744.
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Aldali, Yasser. "Solar thermal and photovoltaic electrical generation in Libya." Thesis, Edinburgh Napier University, 2012. http://researchrepository.napier.ac.uk/Output/5272.
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This thesis investigates the application of large scale concentrated solar (CSP) and photovoltaic power plants in Libya. Direct Steam Generation (DSG) offers a cheaper and less risky method of generating electricity using concentrated solar energy than Heat Transfer Fluid (HTF) plant. However, it is argued that the location of a DSG plant can be critical in realising these benefits, and that the South-East part of Libya is ideal in this respect. The models and calculations presented here are the result of an implementation of the 2007 revision of the IAPWS equations in a general application based on Microsoft Excel and VBA. The hypothetical design for 50MW DSG power plant discussed in this thesis is shown to yield an 76% reduction in greenhouse gas emissions compared to an equivalent gas-only plant over the ten-hour daily period of operation. Land requirement is modest at 0.7km2. A new method for improving the distribution of heat within the absorber tube wall was developed. Internal helical fins within the absorber tube have been proposed to provide a regularly pitched and orderly distribution of flow from the ‘hot' to the ‘cold' side of the absorber tube. Note that the irradiance profile on the absorber tube is highly asymmetric. A CFD simulation using FLUENT software was carried out for three types of pipes with different internal helical-fin pitch, and an aluminium pipe without fins. The results show that the thermal gradient between the upper and lower temperature for the pipe without a helical fin is considerably higher compared with the pipes with helical fins. Also, the thermal gradient between the two halves for the aluminium pipe (without a helical fin) is much lower when compared to the result for the traditional steel pipe (without a helical fin). A 50MW PV-grid connected (stationary and tracking) power plant design in Al-Kufra, Libya has been carried out presently. A hetero-junction with intrinsic thin layer (HIT) type PV module has been selected and modelled. The effectiveness of the use of a cooling jacket on the modules has been evaluated. A Microsoft Excel-VBA program has been constructed to compute slope radiation, dew-point, sky temperature, and then cell temperature, maximum power output and module efficiency for this system, with and without water cooling for stationary system and for tracking system without water cooling. The results for energy production show that the total energy output is 114GWh/year without a water cooling system, 119GWh/year with a water cooling system for stationary system and 148GWh/year for tracking system. The average module efficiency with and without a cooling system for the stationary system is 17.2% and 16.6% respectively and 16.2% for the tracking system. The electricity generation capacity factor (CF) and solar capacity factor (SCF) for stationary system were found to be 26% and 62.5% respectively and 34% and 82% for tracking system. The payback time for the proposed LS-PV power plant was found to be 2.75 years for the stationary system and 3.58 years for the tracking system. The modelling that was carried was based on the measurements conducted on the experimental system set in a city in the southern part of Turkey. Those measurements are recorded by a Turkish team at Iskanderun. As well as the current, voltage and cell temperature of the photovoltaic module, the environmental variables such as ambient temperature and solar irradiance were measured. These data were used for validation purposes. The correlation for the conversion of solar irradiation from horizontal to sloped surface indicated that the presently used model is highly successful reflected by the goodness of fit parameters: the coefficient of determination is 0.97, and the mean bias error -2.2W/m2. Similarly, the cell temperature model used in the present thesis is validated by the following correlation parameters R2 = 0.97 oC, while MBE is 0.7 and RMSE = 2.1 oC.
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LA, CROCE SIMONE. "Simulazione energetica di scenari per la produzione combinata a servizio di edifici civili in area mediterranea." Doctoral thesis, Università degli Studi di Cagliari, 2016. http://hdl.handle.net/11584/266780.
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Increasing regulation on greenhouse gas emissions aimed at fighting climate change has
significantly boosted construction and architecture sectors. Recent European directives
(2010/31/UE e 2012/27/UE) promote the reformulation of energetic planning rules and the
adoption of environmental-friendly models including the nearly zero-energy buildings, which
can be realised through increased energy efficiency, optimised energy production and the
systematic use of renewable energies. In this context, the civil sector plays a key role in both the
erection of new buildings and in the retrofitting of the existing ones, especially with respect to
energy production.
The present work aims at studying plant design technologies and configurations for the
combined production in civil buildings, focusing on the problematic energy situation of the
Mediterranean region. The study resulted in the development of a calculation code (in Matlab
environment) for the energetic simulation of different scenarios of combined production, which
used high-efficiency on market technologies based on renewable energies.
Comparing different solar energy conversion technologies, co-trigenerative solutions and
solar cooling systems for a Mediterranean-like electricity consumption, and using the calculation
code herein developed, it was possible to analyse the energetic behaviour and to determine its
main environmental and economic-financial parameters. The consequent sensitivity analyses
highlighted the significant incidence of energetic costs and of the efficiency parameters of the
single technologies, reflecting the substantial differences observed in the final results of the
simulations.
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Haas, Connor. "Implementing Photovoltaic Panels and Thermal Water Heating." The University of Arizona, 2014. http://hdl.handle.net/10150/337205.
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Sustainable Built Environments Senior CapstoneIn today’s society we are faced with many problems that result from the use of traditional energy sources. Due to the lack of efficient alternative energy sources we are consistently trying to produce technologically advanced methods and tools to offset our dependency on traditional energy systems that are harming the planet as a whole. Every great accomplishment needs a starting point. The University of Arizona is going to an influential success story that gets the ball rolling. Implementing two energy saving tools known as photovoltaic panels and thermal water heating units will allow advocates to see the benefits that can come from sustainable technology. Through state and federal incentives solar panels are able to pay themselves off over the years in a majority of the states. Without federal or state incentives, the solar panels would not save the consumer enough money to repay their initial investment. Thermal water heating units save the consumer enough money to pay themselves off over the years. Overall both thermal water heating units and photovoltaic panels provide a clean source of energy.
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Guarracino, Ilaria. "Hybrid photovoltaic and solar thermal (PVT) systems for solar combined heat and power." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58172.
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Solar is a particularly promising sustainable energy source in terms of its potential to displace the burning of fossil fuels for heat and power, heating and even cooling, albeit at a cost. The sun load-factor profile has a close and predictable match to the daily varying energy demand for heat and electricity, both thermal and electrical, and thermal storage for periods of low irradiance can be made readily available. In addition, solar thermal technologies can provide a significant fraction of the hot water demand in households, as well as space heating and cooling in residential buildings and for industrial facilities. In fact, solar heating has been proposed as one of the leading solutions in terms of its potential for greenhouse gas abatement [1]. At the small scale, photovoltaic systems presently dominate the domestic solar market with solar to electrical conversion efficiencies of around 15% and at a competitive cost for the building owner. Solar photovoltaic installations were encouraged in Europe at the local level with financial support and now constitute a large and mature market with continuously falling prices. Solar thermal systems are able to make use of a larger proportion of the solar resource as they convert solar energy into heat with a higher efficiency than the PV conversion efficiency. Moreover, the low temperature heat may be used to satisfying the largest portion of the demand for thermal energy that is currently met by fossil fuels. The development of the solar thermal market is strongly dependent on the availability of the local irradiance level and on the cost of the alternative sources of thermal energy. In some countries in Europe the solar thermal market is quite mature (e.g. Austria), whilst in others, such as in the UK, solar thermal energy still contributes marginally to the energy mix and solar thermal systems are not yet cost competitive. Due to the high costs of solar thermal energy systems, these constitute a relatively small market at present with the potential to grow substantially in the near future. A competitive solution for energy (heat and power) provision in buildings is the development of combined solar photovoltaic/thermal (PVT) systems which produce both electricity and heat simultaneously from the same aperture area. This solution is particularly suited to residential applications in urban areas, where the demand for electricity is accompanied by a demand for low temperature heat, and space for solar installations is scarce. Many alternative technologies for PVT integration exist and PVT units can be coupled with various systems for domestic hot water generation and/or space heating. At the design stage of a PVT system, decisions have to be made on the absorber characteristics (consisting of thermal collector and PV laminate), on the thermal to electrical yield ratio and on the application (industrial or residential application, stand alone or grid connected). These design parameters influence the requirements on the fluid temperature and electricity output, and the overall efficiency. In addition, system control can significantly impact the potential of such systems in terms of their performance characteristics in different applications. The aim of this present research effort was to demonstrate the technical and practical feasibility of a novel, high-efficiency hybrid PVT water system, by considering an affordable, small-scale, modular unit that can be scaled easily to cater to varying demand levels. The research investigated the technical issues related to PVT panel technology, by looking in particular at the optical efficiency of the PV cells, at the heat transfer from the PV cells to the fluid, and at the integration of such a unit in a heat and power provision system that attempts to match generation and local demand. A detailed numerical model was developed that constitutes a tool for testing various collector and system designs. The model was validated against experimental data. An experimental apparatus was designed and constructed for the purpose of evaluating the collector model and for collecting a database of performance data on PVT collectors. Collector performance data are scarce at the moment due to the relatively small market size, thus the work constitutes a reference for further development and analysis of this type of collectors. Steady-state tests and dynamic tests were performed on PVT collectors and the results were used to develop a reliable model of collector performance over a wide range of time-varying operating conditions. The model allowed for assessments of various solar PVT system designs under different operating conditions and control strategies. Result showed that such systems may underperform if their operation and design is not designed specifically for the local weather conditions and user-demand specific requirements. It is envisaged that emissivity control applied to the solar cells should be adopted for PVT system application, especially if higher operating temperatures are required (e.g. in combination with thermally driven/heat powered cooling systems). The numerical model confirms that solar cells a with low emissivity coating can maximise the thermal energy output of a PVT system. The potential of improved PVT systems is finally assessed from an economic perspective, in an analysis that considers the potential cost reduction of PVT systems in relation to alternative technologies used as a benchmark.
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Linde, Daniel. "Evaluation of a Flat-Plate Photovoltaic Thermal (PVT) Collector prototype." Thesis, Högskolan Dalarna, Energiteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:du-24061.
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This Master thesis, in collaboration with Morgonsol Väst AB, was completed as a part of the Solar Energy engineering program at Dalarna University. It analyses the electrical and thermal performance of a prototype PVT collector developed by Morgonsol Väst AB. By following the standards EN 12975 and EN ISO 9806 as guides, the thermal tests of the collector were completed at the facility in Borlänge. The electrical performance of the PVT collector was evaluated by comparing it to a reference PV panel fitted next to it. The result from the tests shows an improved electrical performance of the PVT collector caused by the cooling and a thermal performance described by the linear efficiency curve ηth=0.53-21.6(Tm-Ta/G). The experimental work in this thesis is an initial study of the prototype PVT collector that will supply Morgonsol Väst with important data for future development and research of the product.
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Bierman, David M. (David Matthew). "Where solar thermal meets photovoltaic for high-efficiency power conversion." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93859.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 71-73).
To develop disruptive techniques which generate power from the Sun, one must understand the aspects of existing technologies that limit performance. Solar thermal and solar photovoltaic schemes dominate today's solar market but both bring intrinsic and practical constraints. What will tomorrow's solar market look like? Third generation solar power generation techniques to utilize a larger portion of the solar spectrum are a promising path for high efficiency power generation, but experimental demonstrations remain limited. In this work, the components of a solar thermophotovoltaic power converter are introduced and discussed. While solar thermophotovoltaic devices have the potential to convert sunlight into electricity at astronomically high efficiencies, there are a number of practical challenges that must first be addressed. Novel photonic materials, design concepts, and both intrinsic and practical limitations of solar thermophotovoltaic conversion are explored in this thesis. The conversion mechanisms as well as a number of experimental implementations are presented. Finally, the device performance is characterized and both geometrical and spectral improvements are discussed.
by David M. Bierman.
S.M.
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Assembe, Cedric Obiang. "Integrated solar photovoltaic and thermal system for enhanced energy efficiency." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2387.
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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016.South Africa has raised concerns regarding the development of renewable energy sources such as wind, hydro and solar energy. Integration of a combined photovoltaic and thermal system was considered to transform simultaneous energy into electricity and heat. This was done to challenge the low energy efficiency observed when the two solar energy conversion technologies are employed separately, in order to gain higher overall energy efficiency and ensure better utilization of the solar energy. Therefore, the notion of using a combined photovoltaic and thermal system was to optimize and to improve the overall PV panel efficiency by adding conversion to thermal energy for residential and commercial needs of hot water or space heating or space cooling using appropriate technology. The PV/T model constructed using water as fluid like the one used for the experimental work, presented a marginal increase in electrical efficiency but a considerable yield on the overall PV/T efficiency, because of the simultaneous operation by coupling a PV module with a thermal collectors.
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Karadağ, Çağlar Günaydın H. Murat. "Design and thermal analysis of a rotating solar building/." [s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezlerengelli/master/enerjimuh/T000358.pdf.
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Misara, Siwanand [Verfasser]. "Thermal Impacts on Building Integrated Photovoltaic (BIPV) (Electrical, Thermal and Mechanical Characteristics) / Siwanand Misara." Kassel : Universitätsbibliothek Kassel, 2015. http://d-nb.info/1073852482/34.
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Bakar, Siti Hawa Abu. "Novel rotationally asymmetrical solar concentrator for the building integrated photovoltaic system." Thesis, Glasgow Caledonian University, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.700990.
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Allan, James. "The development and characterisation of enhanced hybrid solar photovoltaic thermal systems." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/11624.
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A photovoltaic thermal solar collector (PVT) produces both heat and electricity from a single panel. PVT collectors produce more energy, for a given area, than conventional electricity and heat producing panels, which means they are a promising technology for applications with limited space, such as building integration. This work has been broken down into 3 subprojects focusing on the development of PVT technology. In the first subproject an experimental testing facility was constructed to characterise the performance of PVT collectors. The collectors under investigation were assembled by combining bespoke thermal absorbers and PV laminates. Of the two designs tested, the serpentine design had the highest combined efficiency of 61% with an 8% electrical fraction. The header riser design had a combined efficiency of 59% with an electrical fraction of 8%. This was in agreement with other results published in literature and highlights the potential for manufacturers of bespoke thermal absorbers and PV devices to combine their products into a single PVT device that could achieve improved efficiency over a given roof area. In the second project a numerical approach using computational fluid dynamics was developed to simulate the performance of a solar thermal collector. Thermal efficiency curves were simulated and the heat removal factor and heat loss coefficient differed from the experimental measurements by a maximum of 12.1% and 2.9% respectively. The discrepancies in the findings is attributed to uncertainty in the degree of thermal contact between the absorber and the piping. Despite not perfectly matching the experimental results, the CFD approach also served as a useful tool to carry out performance comparisons of different collector designs and flow conditions. The effect of 5 different flow configurations for a header collector was investigated. It was found that the most efficient design had uniform flow through the pipe work which was in agreement with other studies. The temperature induced voltage mismatch, that occurs in the PV cells of PVT collector was also investigated. It was concluded that the temperature variation was not limiting and the way in which PV cells are wired together on the surface of a PVT collector did not influence the combined electrical power output.
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Baig, Hasan. "Enhancing performance of building integrated concentrating photovoltaic systems." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/17301.
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Buildings both commercial and residential are the largest consumers of electricity. Integrating Photovoltaic technology in building architecture or Building Integrated Photovoltaics (BIPV) provides an effective means for meeting this huge energy demands and provides an energy hub at the place of its immediate requirement. However, this technology is challenged with problems like low efficiency and high cost. An effective way of improving the solar cell efficiency and reducing the cost of photovoltaic systems is either by reducing solar cell manufacturing cost or illuminating the solar cells with a higher light intensity than is naturally available by the use of optical concentrators which is also known as Concentrating Photovoltaic (CPV) technology. Integrating this technology in the architecture is referred as Building integrated Concentrating Photovoltaics (BICPV). This thesis presents a detailed performance analysis of different designs used as BICPV systems and proposes further advancements necessary for improving the system design and minimizing losses. The systems under study include a Dielectric Asymmetric Compound Parabolic Concentrator (DiACPC) designed for 2.8×, a three-dimensional Cross compound parabolic concentrator (3DCCPC) designed for 3.6× and a Square Elliptical Hyperbolic (SEH) concentrator designed for 6×. A detailed analysis procedure is presented showcasing the optical, electrical, thermal and overall analysis of these systems. A particular issue for CPV technology is the non-uniformity of the incident flux which tends to cause hot spots, current mismatch and reduce the overall efficiency of the system. Emphasis is placed on modelling the effects of non-uniformity while evaluating the performance of these systems. The optical analysis of the concentrators is carried out using ray tracing and finite element methods are employed to determine electrical and thermal performance of the system. Based on the optical analysis, the outgoing flux from the concentrators is predicted for different incident angles for each of the concentrators. A finite element model for the solar cell was developed to evaluate its electrical performance using the outputs obtained from the optical analysis. The model can also be applied for the optimization of the front grid pattern of Si Solar cells. The model is further coupled within the thermal analysis of the system, where the temperature of the solar cell is predicted under operating conditions and used to evaluate the overall performance under steady state conditions. During the analysis of the DiACPC it was found that the maximum cell temperature reached was 349.5 K under an incident solar radiation of 1000 W/m2. Results from the study carried on the 3DCCPC showed that a maximum cell temperature of 332 K is reached under normal incidence, this tends to bring down the overall power production by 14.6%. In the case of the SEH based system a maximum temperature of 319 K was observed on the solar cell surface under normal incidence. An average drop of 11.7% was found making the effective power ratio of the system 3.4. The non-uniformity introduced due to the concentrator profile causes hotspots in the BICPV system. The non-uniformity was found to reduce the efficiency of the solar cell in the range of 0.5-1 % in all the three studies. The overall performance can be improved by addressing losses occurring within different components of the system. It was found that optical losses occurred at the interface region formed due to the encapsulant spillage along the edges of the concentrator. Using a reflective film along the edge of the concentrating element was found to improve the optical efficiency of the system. Case studies highlighting the improvement are presented. A reflective film was attached along the interface region of the concentrator and the encapsulant. In the case of a DiACPC, an increase of 6% could be seen in the overall power production. Similar case study was performed for a 3DCCPC and a maximum of 6.7% was seen in the power output. To further improve the system performance a new design incorporating conjugate reflective-refractive device was evaluated. The device benefits from high optical efficiency due to the reflection and greater acceptance angle due to refraction. Finally, recommendations are made for development of a new generation of designs to be used in BiCPV applications. Efforts are made towards improving the overall performance and reducing the non-uniformity of the concentrated illumination.
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Giovanardi, Alessia. "Integrated solar thermal facade component for building energy retrofit." Doctoral thesis, University of Trento, 2012. http://eprints-phd.biblio.unitn.it/782/1/AlessiaGiovanardi_DepositoLegale_TesiPhD.pdf.
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In the perspective of the "Net Zero Energy Buildings" as specified in the EPBP 2010/31/EU, herein a modular unglazed solar thermal facade component for facilitating the installation of active solar thermal facades has been conceived and designed to answer three considerations: (1) easily installable elements, offering high modularity to be sized for the specific needs of the buildings considered, (2) low-price unglazed technology, given by the industrial process already developed for the fridge evaporators, and (3) versatile modules to be used for both new buildings and for existing buildings for energy retrofitting.
The existing buildings stock offers a high-potential opportunity to improve the energy efficiency when using such a system. Indeed, the building envelope elements have a significant impact on energy consumptions and performances of the building, and this is a key aspect to consider during renovation.
Considering buildings integrating solar thermal (BIST) by the means of facade retrofitting of solar thermal collectors (STC) opens up new challenges for engineers. Facade usage, compared to the traditional roof installations, offers two interesting potentialities: (1) increased available surfaces, and (2) minimization of the unwanted overheating problem, that appears in summer, thanks to the vertical tilt (as the energy production is almost constant over the year). This allows sizing the STC according to the actual heat needs and avoids as much as possible energy fluxes mismatch.
The design methodology of such a modular component is the main contribution of the PhD work.
The challenges are tackled via a parametric approach. Dynamic simulation tools support the design choices for the energy systems of BIST and to optimize the interactions between the envelope and the STC with the criteria of reducing the overall energy consumption. This methodology is described and applied to the design of a modular prototype of an innovative facade component integrating unglazed STC.
We first analyze a variety of typologies of buildings as potential commercial targets of the facade component of unglazed STC integrated facade element. Both residential and non residential buildings are considered. The purpose of this analysis is to match the heat loads for properly sizing the facade elements for each typology.
Benchmark models of buildings from the Department of Energy are used such as multifamily houses, hospitals, big and small hotels, schools, offices. These are simulated through EnergyPlus in three European locations (Stockholm, Zurich and Rome) in order to define the yearly heat loads for domestic hot water (DHW) and space heating (SH) needs.
Finally, the prototype is conceived and designed as a low-cost product to implement into facades with the criteria of optimizing the energy production. The unglazed STC is combined with a simple configuration of combisystem in order to define some rule of thumbs through Trnsys. By the fact that the energy is produced at lower temperatures, if compared with glazed flat plate collectors, this technology is potential applicable to those buildings having the proper heat loads and the suitable system layout.
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CORONA, FABIO. "Building Integrated Photovoltaic Systems: specific non-idealities from solar cell to grid." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2538891.
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After an initial phase of great diffusion of large Photovoltaic (PV) systems installed on the ground, the recent evolution of the feed-in tariffs makes the Building
Integrated PV (BIPV) systems for residential, commercial and industrial users, the more befitting application of the PV technology.
Unfortunately, the building integration implies some critical issues on the operation of principal components, such as the PV panels or the grid-connected inverter, typical of this kind of installation and not so important in the case of ground mounted PV plants. These non-idealities can be due to: presence of obstacles near the PV panels, like trees, poles, antennas, architectural elements (chimneys, barriers, buildings in the neighbourhood); non-optimal orientation of the PV field (not Southward) or with different orientations among the sub-fields,
with consequent production asymmetry between morning and evening or mismatch; sub-optimal tilt angle of the PV modules, as it is fixed by the building roof; not-efficient cooling of the PV panels, which can cause temperature gradients both horizontally, between PV modules in the central area of the field and the peripheral ones, and vertically, between panels installed in the bottom and in the top of a structure, due to the direction of the cooler flow.
The consequences of these non-idealities is the subject of this PhD dissertation, from both theoretical, through convenient simulation tools, and experimental viewpoints. The most evident of these effects is the mismatch of the currentvoltage characteristics of the PV field panels. With the aim of illustrating the analysis methodologies used to study the mismatch effect on all the PV system components, a specific case study is considered, constituted by a large BIPV system (almost 1MWp) installed on the roof of a wholesale warehouse.
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Dupeyrat, Patrick. "Experimental development and simulation investigation of a photovoltaic-thermal hybrid solar collector." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0049.
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L´intérêt grandissant pour les bâtiments à haute efficacité énergétique nécessite le développement de nouveaux types d´enveloppe active et multifonctionnelle pouvant couvrir une partie des besoins énergétiques du bâtiment. Les travaux présentés dans cette thèse concernent le développement de capteurs hybrides solaires photovoltaïques thermique pour la production simultanée d´eau chaude sanitaire et d´électricité au sein d´un unique capteur. L’objectif de cette thèse a été dans un premier temps d´analyser la faisabilité et la complexité du concept de capteur hybrides PV-T. Puis, à partir d’un modèle numérique développé spécifiquement pour appuyer la phase de conception du capteur PV-T les raisons expliquant la limitation des performances de tels capteurs ont été analysées, pour enfin proposer différentes solutions innovantes, tant au niveau des cellules solaires que des matériaux du modules PV et du design du capteur final afin d´en augmenter les performances. L´approche développée est par conséquent multi-échelle allant de la prise en compte des phénomènes physiques pris isolément, des propriétés locales des matériaux jusqu’à la mise en œuvre d’un composant et à l´analyse énergétique et exergétique de ses performances dans un environnement numérique dédié au bâtimentIn the context of greenhouse gas emissions and fossil and fissile resources depletion, solar energy is one of the most promising sources of power. The building sector is one of the biggest energy consumers after the transport and industrial sectors. Therefore, making use of a building’s envelope (façades and roofs) as solar collecting surfaces is a big challenge facing local building needs, specifically in regard to heat, electricity and cooling. However, available surfaces of a building with suitable orientation are always limited, and in many cases a conflict occurs between their use for either heat or electricity production. This is one of the reasons why the concept of a hybrid photovoltaic-thermal (PV-T) collector seems promising. PV-T collectors are multi-energy components that convert solar energy into both electricity and heat. In fact, PV-T collectors make possible the use of the large amount of solar radiation wasted in PV modules as usable heat in a conventional thermal system. Therefore, PV-T collectors represent in principle one of the most efficient ways to use solar energy (co-generation effect). However, such a concept still faces various barriers due to the multidisciplinary knowledge requirements (material, semi-conductors, thermal) and to the complexity of the multiple physical phenomena implied in such concepts.The objective of this PhD work is to carry out a study based on a multi-scale approach that combines both numerical and experimental investigations regarding the feasibility of the concept of hybrid solar collector. The performance of such components is estimated through an appropriate design analysis, and innovative solutions to design an efficient PV-T collector are presented. Based on improved processing methods and improved material properties, an efficient covered PV-T collector has been designed and tested. This collector was made of PV cells connected to the surface of an optimized flat heat exchanger by an improved lamination process and covered on the front side by a static air layer and AR-coated glass pane and on the back side by thermal insulation material. The results showed a significant improvement of both thermal and electrical efficiency in comparison to all previous works on PV-T concepts found in the literature. System simulations were carried out for a hot water system with the software TRNSYS in order to get a clearer statement on the performance of PV-T collectors. The results show that the integration of PV-T collectors can be more advantageous than standard solar components in regard to thermodynamic considerations (energy and exergy) and environmental considerations (CO2 and primary energy saving)
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Kamanzi, Janvier. "Thermal electric solar power conversion panel development." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2527.
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Thesis (DTech (Engineering))--Cape Peninsula University of Technology, 2017.The world has been experiencing energy-related problems following pressuring energy demands which go along with the global economy growth. These problems can be phrased in three paradoxical statements: Firstly, in spite of a massive and costless solar energy, global unprecedented energy crisis has prevailed, resulting in skyrocketing costs. Secondly, though the sun releases a clean energy, yet conventional plants are mainly being run on unclean energy sources despite their part in the climate changes and global warming. Thirdly, while a negligible percentage of the solar energy is used for power generation purposes, it is not optimally exploited since more than its half is wasted in the form of heat which contributes to lowering efficiency of solar cells and causes their premature degradation and anticipated ageing. The research is geared at addressing the issue related to unsatisfactory efficiencies and anticipated ageing of solar modules. The methodology adopted to achieve the research aim consisted of a literature survey which in turn inspired the devising of a high-efficiency novel thermal electric solar power panel. Through an in-depth overview, the literature survey outlined the rationale of the research interest, factors affecting the performance of PVs as well as existing strategies towards addressing spotted shortcomings. While photovoltaic (PV) panels could be identified as the most reliable platform for sunlight-to-electricity conversion, they exhibit a shortcoming in terms of following the sun so as to maximize exposure to sunlight which negatively affects PVs’ efficiencies in one hand. On the other hand, the inability of solar cells to reflect the unusable heat energy present in the sunlight poses as a lifespan threat. Strategies and techniques in place to track the sun and keep PVs in nominal operational temperatures were therefore reviewed.
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Sharma, Shivangi. "Performance enhancement of building-integrated concentrator photovoltaic system using phase change materials." Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/33859.
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Building-integrated Concentrator Photovoltaic (BICPV) technology produces noiseless and pollution free electricity at the point of use. With a potential to contribute immensely to the increasing global need for a sustainable and low carbon energy, the primary challenges such as thermal management of the panels are overwhelming. Although significant progress has been made in the solar cell efficiency increase, the concentrator photovoltaic industry has still to go a long way before it becomes competitive and economically viable. Experiencing great losses in their electrical efficiencies at high temperatures that may eventually lead to permanent degradation over time, affects the market potential severely. With a global PV installed capacity of 303 GW, a nominal 10 °C decrease in their average temperatures could theoretically lead to a 5 % electricity efficiency improvement resulting in 15 GW increase in electricity production worldwide. However, due to a gap in the research knowledge concerning the effectiveness of the available passive thermal regulation techniques both individually and working in tandem, this lucrative potential is yet to be realised. The work presented in this thesis has been focussed on incremental performance improvement of BICPV by developing innovative solutions for passive cooling of the low concentrator based BICPV. Passive cooling approaches are selected as they are generally simpler, more cost-effective and considered more reliable than active cooling. Phase Change Materials (PCM) have been considered as the primary means to achieve this. The design, fabrication and the characterisation of four different types of BIPCV-PCM assemblies are described. The experimental investigations were conducted indoors under the standard test conditions. In general, for all the fabricated and assembled BICPV-PCM systems, the electrical power output showed an increase of 2 %-17 % with the use of PCM depending on the PCM type and irradiance. The occurrence of hot spots due to thermal disequilibrium in the PV has been a cause of high degradation rates for the modules. With the use of PCM, a more uniform temperature within the module could be realised, which has the potential to extend the lifetime of the BICPV in the long-term. Consequentially, this may minimise the intensive energy required for the production of the PV cells and mitigate the associated environmental impacts. Following a parallel secondary approach to the challenge, the design of a micro-finned back plate integrated with a PCM containment has been proposed. This containment was 3D printed to save manufacturing costs and time and for reducing the PCM leakage. An organic PCM dispersed with high thermal conductivity nanomaterial was successfully tested. The cost-benefit analysis indicated that the cost per degree temperature reduction (£/°C) with the sole use of micro-fins was the highest at 1.54, followed by micro-fins + PCM at 0.23 and micro-fins + n-PCM at 0.19. The proposed use of PCM and application of micro-finned surfaces for BICPV heat dissipation in combination with PCM and n-PCM is one the novelties reported in this thesis. In addition, an analytical model for the design of BICPV-PCM system has been presented which is the only existing model to date. The results from the assessment of thermal regulation benefits achieved by introducing micro-finning, PCM and n-PCM into BICPV will provide vital information about their applicability in the future. It may also influence the prospects for how low concentration BICPV systems will be manufactured in the future.
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Buker, Mahmut Sami. "Building integrated solar thermal collectors for heating & cooling applications." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/29009/.
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International Energy Agency Solar Heating & Cooling (IEA SHC) programme states the fact that space/water heating and cooling demand account for over 75% of the energy consumed in single and multi-family homes. Solar energy technology can meet up to 100% of this demand depending on the size of the system, storage capacity, the heat load and the region’s climate. Solar thermal collectors are particular type of heat extracting devices that convert solar radiation into thermal energy through a transport medium or flowing fluid. Although hybrid PV/T or thermal-alone systems offer some advantages to improve the solar heat utilisation, there are a few technical challenges found in these systems in practice that prevented wide-scale applications. These technical drawbacks include being expensive to make and install, inability of switching already-built photovoltaic (PV) systems into PV/T systems, architectural design etc. The aims of this project, therefore, were to investigate roof integrated solar thermal roof collectors that properly blend into surrounding thus avoiding ‘add on’ appearance and having a dual function (heat absorption and roofing). Another objective was to address the inherent technical pitfalls and practical limitations of conventional solar thermal collectors by bringing unique, inexpensive, maintenance free and easily adaptable solutions. Thus, in this innovative research, unique and simple building integrated solar thermal roof collectors have been developed for heating & cooling applications. The roof systems which mainly based on low cost and structurally unique polyethylene heat exchanger are relatively cost effective, competitive and developed by primarily exploiting components and techniques widely available on the market. The following objectives have been independently achieved via evaluating three aspects of investigations as following: • Investigation on the performance of poly heat exchanger underneath PV units • Investigation on the performance of a Building Integrated PV/T Roof ‘Invisible’ Collector combined with a liquid desiccant enhanced indirect evaporative cooling system • Investigation on the build-up and performance test of a novel ‘Sandwich’ solar thermal roof for heat pump operation These works have been assessed by means of computer simulation, laboratory and field experimental work and have been demonstrated adequately. The key findings from the study confirm the potential of the examined technology, and elucidate the specific conclusions for the practice of such systems. The analysis showed that water temperature within the poly heat exchanger loop underneath PV units could reach up to 36°C and the system would achieve up to 20.25% overall thermal efficiency. Techno-economic analysis was carried out by applying the Life Cycle Cost (LCC) method. Evaluations showed that the estimated annual energy savings of the overall system was 10.3 MWh/year and the cost of power generation was found to be £0.0622 per kWh. The heat exchanger loop was coupled with a liquid desiccant enhanced indirect evaporative cooling unit and experimental results indicated that the proposed system could supply about 3 kW of heating and 5.2 kW of cooling power. Lastly, the results from test of a novel solar thermal collector for heat pump operation presented that the difference in water temperature could reach up to 18°C while maximum thermal efficiency found to be 26%. Coefficient Performance of the heat pump (COPHP) and overall system (COPSYS) averages were attained as COPHP=3.01 and COPSYS=2.29, respectively. An economic analysis pointed a minimum payback period of about 3 years for the system.
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Mallick, Tapas K. "Optics and heat transfer for asymmetric compound parabolic photovoltaic concentrators for building integrated photovoltaics." Thesis, University of Ulster, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288897.
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Wormald, Roy. "Solar energy in construction : an assessment of solar wall thermal performance in Europe." Thesis, Liverpool John Moores University, 1998. http://researchonline.ljmu.ac.uk/5059/.
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Haredy, Abdullah. "Simulation of photovoltaic airflow windows for indoor thermal and visual comfort and electricity generation." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32523/.
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The alleviation of heating (in winter), cooling (in summer), artificial lighting and electricity use in office facilities is defined as a bioclimatic trend that offers sustainable building practice through a semi-transparent building integrated photovoltaic thermal envelope as a photovoltaic airflow window system. This thesis aims to produce synthesised design and strategies for the use of a proposed airflow window unit in office building in any given location and to maximise use of the renewable energy. Computational Fluid Dynamics (CFD), namely ANSYS Fluent 14.0, and ECOTECT have been employed to model the mechanical and natural ventilation of an office building integrated with a semi-transparent photovoltaic airflow window and the daylighting impact of various PV transparent degrees (15, 20, 25, 30 and 35 per cent) on the interior space, respectively, for winter and summer conditions. The use of such software has urged to establish a validation analysis a priori in order to ascertain the applicability of the tools to the targeted examination. The validation process involved a comparison of the results of CFD turbulence models, first, against benchmark and, second, against results of literature for identical component. The results of ECOTECT, in terms of daylight factor and illuminance level, were also compared against the results of Daysim/radiance, Troplux and BC/LC found in the literature. Excellent agreement was attained from the comparison of the results with errors less than 10 per cent. The study presents results of modelling of the airflow window system integrated into an office room for energy efficiency and adequate level of thermal and visual comfort. Results have revealed that the combination of mechanical and buoyancy induced flow spreads the heat internally warming the space to be thermally acceptable during the heating season whilst the mechanical convection is a main force for the cooling season. The thermal and visual comfort was compared for different PV airflow window transparent levels to determine the optimum PV transparency for the office space. Moreover, time-dependant and steady state conditions were imposed to predict the thermal and air behaviour for more elaborate investigation. The transient analysis was carried out, in sequential and individual base, according to the solar irradiance of each minute of working period, 8am-4pm (winter) and 5am-7pm (summer). The results obtained from transient and steady state, for both seasons, were compared and revealed negligible impact of transient effect. The PV electricity output was calculated from each transparency level under each condition, summer and winter (transient and steady). The predicted flow patterns, temperature distribution and the daylight factors in the room have been used to determine the most appropriate opening locations, sizes and system specifications for maintaining a comfortable indoor environment. The simulation investigation show that, for the proposed window model, optimum thermal and visual performance can be achieved from the PV transparency level of 20 per cent, during the heating season, and from the PV transmittance of 15 per cent, during the cooling season, where the PV output is highest. However the PV transparencies of 25, 30 and 35% can be reliable under altered conditions of operation.
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Shen, Jingchun. "Investigation of a compact unglazed solar thermal façade for building integration." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39477/.
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In order to achieve the global carbon emission reduction target, it is expected to become essential for higher fraction of locally available renewable energy sources in energy mix, other than significant reduction of fossil energy consumption. Solar energy is one of the most promising renewable sources locally with various building applications. In addition, the Solar Thermal Facade (STF) system demonstrates a real sense of building integration that can be a potential solution towards energy efficiency improvement and operational cost reduction in contemporary built environment. This thesis presents a comprehensive investigation into a novel com-pact unglazed STF system that possesses the advantages of compact structure, economical cost and high feasibility in architectural design. The entire study follows in the basic methodology of combined theoretical and experimental analysis, including procedures of critical literature reviews, optimal concept design, theoretical study, analytical model development, prototype system construction, laboratory-controlled evaluation, techno-economic feasibility analysis and a design strategy for its application. Under the baseline testing condition, the collector efficiency factor F’, heat removal factor FR and channel flow factor F’’ were respectively high up to 0.993, 0.992, and 0.985, leading to a relatively high thermal efficiency at about 63.21%, exhibiting a better thermal performance. And the maximum theoretical possible useful heat gain capacity (intercept FRαp) of such STF at the given operating conditions was about 96.20%. And the mean slope (FRUL) was as much as about -13.06, representing a sharp decreasing trend of this SFT’s thermal efficiency against the (Tin-Ta)/I complying with the feature of no glazing cover attached in the front. So in case of current design, such STF could match the applications of heating load for pool heating, domestic hot water and radiant space heating in those areas with warm air temperature and sufficient solar radiation. Moreover, the techno-economic feasibility study identified that the overall contributions of the STF application in a reference residential building consist of direct solar thermal generation, indirect HVAC load reduction and savings in operation cost. Additionally, the financial outputs from the dedicated business model in Shanghai stated that: the proposed STF system was a profitable investment project with positive overall revenue and acceptable payback period within 6 years; and three different investment schemes have individual advantages in terms of investment risk, payback period and financial output. Lastly, the BIM associated STF design strategy was raised for building performance research in architectural practice. It is ultimately about the evaluation of multiple STF alternatives against different design priorities and the associated STF design information sharing with others to reduce duplication, minimize errors, streamline processes and facilitate collaboration towards sustainable STF integration. The entire research is expected to configure a technical breakthrough in the subject for the widespread market penetration of the STF technology, a feasible solution for solar thermal technology in future building application, as well as an advanced multi-functional STF development. The research outcomes of this study will conduce to the promotion of such a building integrated solar thermal technology, enrich low-carbon building design strategy, and thus contribute to achieving the domestic and international targets for energy saving, renewable energy utilization, and carbon emission reduction in the building sector.
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Muron, Aaron C. D. "Field Installation of a Fully Instrumented Prototype Solar Concentrator System: Thermal and Photovoltaic Analysis." Thesis, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26245.
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Concentrator photovoltaics (CPV) is one of the most promising renewable technologies owing to its high efficiency, scalability, low operating expense, and small environmental impact. However, there is much research and advancements to be made before CPV is established as a cost competitive energy technology. To this end, Morgan Solar has developed the Sun Simba, an innovative light weight and low cost CPV module. Under the “Advancing Photonics for Economical Concentration Systems” (APECS) project, outdoor CPV test and measurement systems were designed and constructed at the University of Ottawa and at Little Rock, CA. The performance and reliability of development stage Sun Simba modules installed at the University of Ottawa is assessed. The Little Rock test system was constructed for purposes of future comparison and assessment. To properly assess the performance, instrumentation and data acquisition systems to measure meterological parameters and the associated electrical performance are described and the long-term performance of Sun Simba modules installed at the University of Ottawa is summarized.
A finite element model of a cell-on-carrier assembly was constructed to explore the parameter space of the carrier and suggest improvements in carrier design. The effect of carrier geometry, material choices, and convective boundary conditions and their influence on the cell efficiency is determined. The modelling results connected to the measured data is used to estimate the heat sinking capability of the second generation Sun Simba modules.
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Thaikattil, Greeta Jose. "Thermal Analysis and Design of the Photovoltaic Investigation on Lunar Surface (PILS) Payload." Cleveland State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=csu1610669542951819.
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Zacharopoulos, Aggelos. "Optical design modelling and experimental characterisation of line-axis concentrators for solar photovoltaic and thermal applications." Thesis, University of Ulster, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342344.
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Zhang, Yi Zhong. "Experimental investigations on a two-axis sun-tracking concentrated photovoltaic-thermal system cooled by phase change material." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3950058.
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Jeong, Ji-Weon. "Hydrogen passivation of defects and rapid thermal processing for high-efficiency silicon ribbon solar cells." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/15615.
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Motaung, David Edmond. "Structure property relationship and thermal stability of organic photovoltaic cells." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_6331_1307942460.
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In this thesis, regioregularpoly( 3-hexylthiophene) (rr-P3HT) polymer was used as a light absorption and electron donating material, while the C60 fullerene and its derivative [6,6]-phenyl C61-butyric acid methyl ester (PCBM) were used as electron acceptor materials. The effect of solvent to control the degree of mixing of the polymer and fullerene components, as well as the domain size and charge transport properties of the blends were investigated in detail using P3HT:C60 films. The photo-physical, structural and electrical transport properties of the polymer blends were carried out according to their ratios. A distinctive photoluminescence (PL) quenching effect was observed indicating a photo-induced electron transfer. In this thesis, the effect of solvents on the crystallization and interchain interaction of P3HT and C60 fullerene films were studied using XRD, UV-vis, PL, Raman and FTIR spectroscopy. The polymer blends formed with non-aromatic solvents exhibited an improved crystallinity and polymer morphology than that formed with aromatic solvents. An improved ordering was demonstrated in the polymer films spin coated from non-aromatic solvents. This indicates that the limited solubility of rr P3HT in a marginal solvent such as non-aromatic solvents can offer a strategy to obtain highly ordered crystal structures and lead directly to optimal morphologies on the films.
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Mtunzi, Busiso. "Design, implementation and evaluation of a directly water cooled photovoltaic- thermal system." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1016198.
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This research project was based on the Design, Implementation and Evaluation of a Photovoltaic Water heating system in South Africa, Eastern Cape Province. The purpose of the study was to design and investigate the scientific and economic contribution of direct water cooling on the photovoltaic module. The method involved performance comparison of two photovoltaic modules, one naturally cooled (M1) and the other, direct water cooled module (M2). Module M2 was used to produce warm water and electricity, hence, a hybrid system. The study focused on comparing the modules’ efficiency, power output and their performance. The temperatures attained by water through cooling the module were monitored as well as the electrical energy generated. A data logger and a low cost I/V characteristic system were used for data collection for a full year. The data were then used for performance analysis of the modules. The results of the study revealed that the directly water cooled module could operate at a higher electrical efficiency for 87% of the day and initially produced 3.63% more electrical energy each day. This was found to be true for the first three months after installation. In the remaining months to the end of the year M2 was found to have more losses as compared to M1 as evidenced by the modules’ performance ratios. The directly water cooled module also showed an energy saving efficiency of 61%. A solar utilization of 47.93% was found for M2 while 8.77% was found for M1. Economically, the project was found to be viable and the payback period of the directly cooled module (M2) system was found to be 9.8 years. Energy economics showed that the system was more sensitive to the price changes and to the energy output as compared to other inputs such as operation and maintenance and years of operation. A generation cost of R0.84/kWh from the system was found and when compared to the potential revenue of R1.18 per kWh, the system was found to enable households to make a profit of 40.5 %. Use of such a system was also found to be able to contribute 9.55% towards carbon emission reduction each year. From these results, it was concluded that a directly cooled photovoltaic/thermal heating (PV/T) system is possible and that it can be of much help in terms of warm water and electricity provision.
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Subedi, Indra. "Optical Evaluation and Simulation of Photovoltaic Devices for Thermal Management." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo155448373019862.
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McDowell, Alastair Kieran Joel. "Thermal modelling and optimisation of building-integrated photo-voltaic thermal systems." Thesis, University of Canterbury. Electrical & Computer Engineering, 2015. http://hdl.handle.net/10092/11079.
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This Masters project has involved detailed thermal analysis of a unique
renewable energies building. A TRNSYS model of this building has been
developed and validated by real measurements and has shown to be capable of accurately predicting room temperatures and total heat gain from a solar-thermal roofing system. Supporting experiments were conducted experimentally and numerically. An experimental solar thermal testing unit constructed for the purpose of validating the solar-thermal roof concept. This experimental apparatus has been used to evaluate the effect of various operating procedures on the total heat gain from the system under a range of meteorological conditions. The validated thermal building model is used to conduct long-term simulations to provide a measure of year-round thermal performance of the building and estimated gains from renewable energy systems. Similar techniques are used to assist in the design and optimisation of a new transportable sustainable building concept in association with StoneWood Homes. It was found that a 4.5kW BIVP/T system could
supply the small building with 100% of the yearly electrical energy and space heating requirements.
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Mayer, Jamie Lynn. "Design of a Rooftop Photovoltaic Array for the George C. Gordon Library at Worcester Polytechnic Institute: Structural, Thermal, and Performance Analysis." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-theses/368.
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In 2009, WPI formed a Presidential Task Force to engage the WPI community in sustainability research, thought, and action. One of the Presidential Task Force's specific objectives is to improve campus environmental performance, which includes energy conservation. Several new buildings such as the Bartlett Center and East Hall have utilized new green building techniques and materials. Older buildings at WPI which were built before new green building techniques and materials were developed can be equipped with photovoltaic systems to reduce the environmental impact and increase clean energy use. This thesis presents a rooftop photovoltaic array design for the George C. Gordon library at WPI which is expected to produce over 27,000 kWh and offset over 56,000 lbs of carbon dioxide emissions annually. The materials science and engineering of the photovoltaic system components are an important part of the design process. Structural and thermal modeling of photovoltaic components during the initial phase of array design is critical to the success of the PV system and maximizing the energy from the system. This thesis presents how differences in photovoltaic materials and mounting systems result in changes in lifetime and reliability. Using common wind, ice, snow and hail loads for the Worcester, MA area ANSYSâ„¢ structural simulations show that an attached mounting system is more structurally stable than a ballasted system. Using local weather data and thermal cycling, ANSYSâ„¢ thermal simulations show that silicon PV modules outperform other technologies at lower temperatures while cadmium telluride PV modules outperform other technologies at higher temperatures. It is recommended that WPI install poly-silicon PV modules, such as Evergreen Solar PV modules, to maximize power output.
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Quintana, Samer. "Building integrated photovoltaic (BIPV) modelling for a demo site in Ludvika based on building information modelling (BIM) platform." Thesis, Högskolan Dalarna, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:du-29078.
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This thesis aims to design and simulate a building integrated photovoltaic (BIPV) system for three demo buildings in Ludvika, Sweden, which is part of the Energy- Matching’s project under the European H2020 research scheme. A literature review was firstly conducted in the area of energy scenarios, engineering tools, methodologies and the workflows in design and building energy modelling. Then, this thesis developed the three-dimensional (3D) building models of the demo site, based on the Revit – a building information modelling (BIM) tool. Next, the PVSITES tool was considered as the main approach to simulate and optimize the BIPV system. Results on the energy output of the dedicated BIPV system, as well as financial costs, were finally obtained. It was found that the optimal location for the BIPV system was on the three buildings south and east faced roofs, with a total area of approximately 800 meters squared (m2) and a yearly irradiance potential between 1020 kilowatts hours per meter squared (kWh/m2) and 925 kWh/m2 respectively. The simulation showed that this BIPV system of 615 m2 with a power of 36 kilowatts-peak (kWp) could yield a maximum of 29,000 kilowatts hours per year (kWh), a 5% of the total yearly energy demand of the building and over the summer, this percentage increases considerably. With the estimated standards costs, the BIPV system have a 12 years payback period and 61% investment ratio over a 20 years period, concluding that a BIPV system on the Ludvika demo building is a feasible project, in terms of energy potential and as well as economically. This thesis also concludes that performing the BIPV simulation on the BIM platform is both reliable and flexible, and also has the potential to be reused, refined and scaled up.
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Deo, Vishwadeep. "Real-Time Adaptive Systems for Building Envelopes." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19769.
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The thesis attempts to investigate the issues pertaining to design, fabrication and
application of real-time adaptive systems for building envelopes, and to answer
questions raised by the idea of motion in architecture. The thesis uses the Solar
Decathlon Competition as a platform to base all the research and consequently to verify
their applications.
Photo-voltaic (PV) panels and shading devices are two different components of
Georgia Institute of Technology s the Solar Decathlon House, located above the roof,
that are based on the concept of Homeostasis or self-regulated optimization. For the
PV panels, the objective is to optimize energy production, by controlling their movement
to track the changing position of Sun, whereas, the objective for the shading devices is
to reduce heating or cooling loads by controlling the position of shading devices, thus
controlling direct and diffused heat gains through the roof.
To achieve this adaptive feature, it required three layers of operations. First was
the design of the mechanics of movement, which tried to achieve the required motion for
the PV panels and shading devices by using minimum components and parameters.
Second was the design of the individual parts that are consistent with the overall concept
of the House. And finally, the third layer is the design of controls that automates the
motion of the PV panels and Shading Devices, using a set of sensors that actuate the
attached motors. As a final product, there is an attempt to integrate the precision and
material efficiency of digital fabrication with the self-regulated optimization of the roof
components.
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Munyati, Edmund. "The potential of building-integrated photovoltaic systems in Zimbabwe and their application to thermal environmental control." Thesis, Northumbria University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367423.
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Andersson, Martin. "Comparison of solar thermal and photovoltaic assisted heat pumps for multi-family houses in Sweden." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-244401.
Full textAbstract:
The building sector account for 40 % of the global energy demand, and an increasingly popular way to supply buildings with heat is through the use of heat pumps. Solar thermal (ST) can either be used as a low temperature energy source in the heat pump or to directly supply the building’s heating demand. The increasing market of PV has made it a favorite for roof-top solar installation. Its physical integration with buildings and HPs is simpler than that of ST and can supply any available electric load associated with the building and not just the HP system. It can also supply any excess power to the grid. In order to properly compare these two options, key performance indicators (KPIs) were identified for several system boundaries within the building and HP system. Technical KPIs used were seasonal performance factor (SPF), solar fraction (SF) and self-consumption (SC), while internal rate of return (IRR), net present value (NPV), profitability index (PI) and payback time was used to evaluate their economic performance. For the thesis a multi-family house was modelled in TRNSYS where different system sizes of either ST or PVs was simulated for a year with three-minute intervals. The ST was connected in a parallel configuration thereby supplying the building’s domestic hot water (DHW) through a separate storage tank. The modelled heat pump was a ground source heat pump (GSHP) which utilizes boreholes as the low temperature energy source. The SPF increased for both the ST and PV integration from the reference scenario (no PV/ST integration) but to a varying degree depending on the analyzed system boundary. The economic results suggested that PVs are the more financially sound option over ST for the simulated MFH. The sensitivity analysis also showed the large impact of economic assumptions on the expected profitability for both the PV and ST systems. Based on the results would the simulated MFH with an existing GSHP benefit more from installing PV instead of ST from both a technical, economic and environmental perspective. It is reasonable that PVs will most likely be an integral part for future buildings in Sweden with or without HPs because of its financial strength and versatility of demand supply, especially compared to ST.Byggsektorn står för 40% av det globala energibehovet, och ett alltmer populärt sätt att leverera värme till ett hus är genom användning av värmepumpar. Solvärmefångare kan antingen användas som en lågtemperaturenergikälla i värmepumpen eller för att direkt leverera byggnadens värmebehov. Den ökande marknaden för solceller har gjort den till en favorit för takmonterad solinstallation. Dess fysiska integration med byggnader är enklare än solvärmefångare och kan leverera el till hea byggnaden och inte bara värmepumpssystemet. Solceller kan också leverera till elnätet om produktionen överstiger byggnadens behov. För att korrekt jämföra dessa två alternativ identifierades viktiga indikatorer för flera systemgränser inom byggnaden och värmepumpssystemet. Tekniska indikatorer som användes var årsvärmefaktor, solfraktion och självförbrukning, medan internränta, nuvärde, lönsamhetsindex och återbetalningstid användes för att utvärdera deras ekonomiska resultat. För uppsatsen modellerades ett flerbostadshus med tillgänglig takyta i TRNSYS där olika systemstorlekar (i kvadratmeter) av antingen solvärmefångare eller solceller var simulerade i ett år med tre minuters intervall. Solvärmefångaren var ansluten i en parallell konfiguration med värmepumpen, varigenom byggnadens varmvatten levereras genom en separat lagertank. Den modellerade värmepumpen var en bergvärmepump som utnyttjar borrhål som lågtemperaturenergikälla. Årsvärmefaktorn ökade för både solvärmefångar- och solcells-integrationen från referensscenariot (ingen solteknisk-integration) men i varierande grad, beroende på den analyserade systemgränsen. De ekonomiska resultaten visade att solceller är det mer ekonomiskt sunda alternativet över solvärmefångare för det simulerade flerbostadshuset. Känslighetsanalysen visade också på den stora effekten av ekonomiska antaganden på den förväntade lönsamheten för både solceller och solvärmefångare. Baserat på resultaten skulle det simulerade flerbostadshuset med en befintlig bergvärmepump dra nytta av att installera solceller istället för solvärmefångare från ett tekniskt, ekonomiskt och miljömässigt perspektiv. Det är troligt att solceller kommer vara en del i framtida byggnader i Sverige med eller utan värmepumpar på grund av den ekonomiska styrkan och möjligheten att tillgodose både byggnaden och elnätet vid överproduktion.