Purpose - In the pursuit of renewable energy sources, solar photovoltaic (PV) is predicted to become the single biggest global source of energy by the year of 2027, part of a trilemma involving climate change, biodiversity and food security. Agrivoltaic (AV) systems, the co-location and potential symbiosis between agricultural activities and solar PV, has thereby arisen as a potential solution for dual land-use. The research within this area is novel, and scholars agree that there is a need for the conceptualization of utility-scale AV in general, and the commercialization process of such systems in particular. Thereby, the purpose of this study is to unravel the key factors, activities and stakeholder involvement in order to assess the commercial potential of utility-scale AV. By addressing research questions: RQ1. What are the key factors for assessing the commercial potential of utility-scale AV?, RQ2. Which activities are essential to address these factors? and RQ3. Who are the key stakeholders that need to be involved in these activities?, a contingency framework for the assessment process has been developed. Method - In order to fulfill the purpose of this study utility-scale AV was approached as a Technology Innovation System (TIS) where the solar energy actor Sunna Group AB (Sunna) enabled insight to the potential industry context of utility-scale AV. Respondents were sampled within the TIS, forming the prerequisites for this multiple case study. Empirical data were collected in three phases: 1) Exploratory, 2) Semi-structured and 3) Final workshop, resulting in 3 workshops and 17 interviews, analyzed by a thematic analysis.  Findings - The thematic analysis resulted in four main themes: 1) Socio-political factors, 2) Techno-economical factors, 3) Meso activities for commercialization and 4) Macro activities for commercialization, under which seven key factors, six overarching activities and the stakeholder involvement in these activities, were revealed. These further formed a contingency framework providing an overview of how these building blocks are interlinked.  Theoretical & practical implications - The resulting framework provides an overview and synthesizes the commercialization of utility-scale AV, bridging the gap between stakeholder involvement and the key factors for assessing the commercial potential. The practical implications of this study primarily involve the solar energy sector, yet deemed to be of value to all potential stakeholders within the ecosystem of AV. Limitations & future research - The limitations of this study includes the potential exclusion of stakeholders within the data collection process due to the complex stakeholder configuration of AV, as well as the geographical constraints limiting this study to the context of Sweden. Future research is encouraged within several fields of this novel research area, predominantly including stakeholder involvement, business model configuration and how to mobilize the synergy sought in technology development between the solar energy- and agricultural sector.

Floating solar technology is relatively new, and it comes with its own set of challenges and opportunities. This master thesis focuses on understanding how Floating Photovoltaic (FPV) projects perform compared to Ground-Based Photovoltaic (GPV) projects, in specific weather conditions. The following work is based on a case study: a floating power plant run by Akuo Energy, where sensors have been installed in order to measure the evolution of relevant physical and weather parameters on-site. Akuo Energy is a French independent renewable energy producer and developer founded in 2007. The company specializes in the development, financing, construction, and operation of renewable energy projects, including wind, solar and storage power plants. It is committed to producing clean, affordable, and reliable energy while promoting sustainable development and supporting local communities. The thesis is conducted within the Solar Technology Team, which centralizes the solar expertise of the company and implements innovative technologies to improve their Photovoltaic (PV) projects’ performances. As the number of FPV projects increases, the team raised the need for better evaluation of their performance compared to a standard GPV project, in terms of output power and energy yield. As it appears in the literature, FPV installations can differ from GPV, due to different operating conditions: power plant designs, module cooling, weather conditions, or degradation rates. These parameters need to be taken into account in the expected energy yield analysis, especially module cooling, since operating temperature has a proved impact on module efficiency. Today, technological and economic considerations on FPV specific design are therefore essential. However, the main solar projects development software PVsyst used at Akuo Energy does not include a default floating solar library. Experimental measurements are a good starting point for understanding how the numerical model needs to evolve to adapt to the FPV system. By examining a practical case and processing historical data, insights on FPV systems and how weather affects their efficiency can be provided. The objective of this thesis is then to better model the FPV array thermal losses due to the cooling effect and better estimate the yield for future Akuo Energy FPV projects during the development phase. / Flytande solteknik är relativt ny och kommer med sina egna utmaningar och möjligheter. Denna masteruppsats fokuserar på att förstå hur FPV-projekt presterar jämfört med GPV-projekt, under specifika väderförhållanden. Följande arbete är baserat på en fallstudie: ett flytande kraftverk som drivs av Akuo Energy, där sensorer har installerats för att mäta utvecklingen av relevanta fysiska parametrar och väderparametrar på plats. Akuo Energy är en fransk oberoende producent och utvecklare av förnybar energi som grundades 2007. Företaget är specialiserat på utveckling, finansiering, konstruktion och drift av projekt för förnybar energi, inklusive vind-, sol- och lagringskraftverk. Det är engagerat i att producera ren, prisvärd och pålitlig energi samtidigt som man främjar hållbar utveckling och stödjer lokala samhällen. Examensarbetet genomförs inom Solar Technology Team, som centraliserar företagets solexpertis och implementerar innovativa teknologier för att förbättraderas PV-projekts prestanda. När antalet FPV-projekt ökar, tog teamet upp behovet av bättre utvärdering av deras prestanda jämfört med ett standard GPV-projekt, vad gäller uteffekt och energiutbyte. Som det framgår av litteraturen kan FPV-installationer skilja sig från GPV på grund av olika driftsförhållanden: kraftverkskonstruktioner, modulkylning, väderförhållanden, eller nedbrytningshastigheter. Dessa parametrar måste beaktas ta hänsyn till den förväntade energiutbytesanalysen, särskilt modulkylning, eftersom driftstemperaturen har en bevisad inverkan på modulens effektivitet. Idag är därför tekniska och ekonomiska överväganden om FPV specifik design viktiga. Emellertid innehåller den huvudsakliga utvecklingsmjukvaran PVsyst för solenergiprojekt som används på Akuo Energy inte ett flytande solcellsbibliotek som standard. Experimentella mätningar är en bra utgångspunkt för att förstå hur den numeriska modellen behöver utvecklas för att anpassa sig till FPV-systemet. Genom att undersöka ett praktiskt fall och bearbeta historiska data kan insikter om FPV-system och hur vädret påverkar deras effektivitet ges. Syftet med denna avhandling är sedan att bättre modellera FPV-matrisens termiska förluster på grund av kyleffekten och bättre uppskatta avkastningen för framtida Akuo Energy FPV-projekt under utvecklingsfasen.

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.

Made available in DSpace on 2014-12-17T14:56:16Z (GMT). No. of bitstreams: 1 AugustoCFW_DISSERT.pdf: 4069800 bytes, checksum: c488b0f09f064b7a5254eca8a4fff499 (MD5) Previous issue date: 2013-08-30 / The generation of electricity in Brazil is predominantly renewable, with internal hydraulic generation being more than 70% of its energy matrix. The electricity rationing occurred in 2001 due to lack of rain, led the country to increase the participation of alternative energy sources. This need for new sources of energy makes the regional potential to be exploited, which configures the change of generation model from centralized generation to distributed generation. Among the alternative sources of energy, the solar energy is presented as very promising for Brazil, given that most of its territory is located near to the equator line, which implies days with greater number of hours of solar radiation. The state of Rio Grande do Norte (RN) has one of the highest levels of solar irradiation of the Brazilian territory, making it eligible to receive investments for the installation of photovoltaic solar plants. This thesis will present the state-of-the-art in solar photovoltaic power generation and will examine the potential for generation of solar photovoltaic power in Brazil and RN, based on solarimetrics measurements conducted by various institutions and also measurements performed in Natal, the state capital / A gera??o de energia el?trica no Brasil ? predominantemente renov?vel, com a gera??o interna hidr?ulica sendo superior a 70% do total de sua matriz energ?tica. O racionamento de energia el?trica ocorrido em 2001, devido ? falta de chuvas, levou o pa?s a incrementar a participa??o de fontes alternativas de energia. Esta necessidade por novas fontes de energia faz com que as potencialidades regionais sejam aproveitadas, o que configura a mudan?a do modelo de gera??o, passando de gera??o centralizada para gera??o distribu?da. Dentre as fontes alternativas de energia, a solar apresenta-se como uma fonte bastante promissora para o Brasil, tendo em vista que a maior parte do seu territ?rio est? localizada pr?ximo ? linha do equador, o que implica em dias com maior quantidade de horas de radia??o solar. O Estado do Rio Grande do Norte (RN) tem um dos maiores ?ndices de incid?ncia solar do territ?rio brasileiro, o que o torna apto a receber investimentos para a instala??o de usinas solares fotovoltaicas. Esta disserta??o apresentar? o estado da arte em gera??o de energia solar fotovoltaica e analisar? o potencial de gera??o da energia solar fotovoltaica no Brasil e no RN, baseando-se em medi??es solarim?tricas realizadas por diversas institui??es e tamb?m em medi??es realizadas em Natal

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2017-12-18T16:25:14Z No. of bitstreams: 2 Dissertação - Ciliana Karine Dias Lima - 2017.pdf: 23149224 bytes, checksum: c070892c298f576da2daf6724723a45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-12-19T12:03:47Z (GMT) No. of bitstreams: 2 Dissertação - Ciliana Karine Dias Lima - 2017.pdf: 23149224 bytes, checksum: c070892c298f576da2daf6724723a45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-19T12:03:47Z (GMT). No. of bitstreams: 2 Dissertação - Ciliana Karine Dias Lima - 2017.pdf: 23149224 bytes, checksum: c070892c298f576da2daf6724723a45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-12-11 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Sustainable development is a present issue in world society and it is also a strategic challenge for Cape Verde’s energy policy in coming years because the large fragilities in the electrical system in Cape Verde such as, dependence on imports of fuels, geographical dispersion, the high costs associated with managing energy systems and the great energy waste. The bet on photovoltaic systems may be one of the alternatives to reducing these fragilities. In this context, the present work highlights the great existent potential for use of renewable energy focused on solar energy. The text describes incentives for the production of electric energy based on renewable sources and presents analyses on the implementation of two grid-connected photovoltaic systems in the island of São Vicente. One of the systems is a photovoltaic rooftop 19.8 kWp plant installed in a public secondary school building and the other system is 3 MWp photovoltaic power plant connected to electrical utility grid in São Vicente Island. The study included design, operation simulation of São Vicente Island distribution network in the presence and absence of photovoltaic systems and financial analyses in order to determine payback time, actual present value, intern return rate of investment and financial sensibility analyses to assess the influence of Wp cost and interest rate on the financial figures. The results show that the implementation of photovoltaic systems is attractive in financial and technical terms, the microgeneration system causes a large reduction in energy acquired by the network, and the large power plant has not worsened the appropriate operating voltage levels and decreased the system's active losses. / O desenvolvimento sustentável é uma questão presente na sociedade mundial e é também um desafio para a política energética de Cabo Verde nos próximos anos, devido às grandes fragilidades do sistema elétrico do arquipélago, tais como a forte dependência da importação dos combustíveis fosseis, a dispersão geográfica, os elevados custos associados à gestão dos sistemas energéticos e o grande desperdício energético. A aposta em sistemas fotovoltaicos é uma das alternativas para a redução dessas fragilidades. Neste contexto, o presente trabalho destaca o grande potencial existente em Cabo Verde para utilização de energia renovável com o foco na fonte solar. O trabalho descreve os incentivos legais locais para a produção de energia elétrica com base em fontes de origem renovável e apresenta a análise da implantação de dois sistemas fotovoltaicos conectados à rede elétrica na ilha de São Vicente. Um deles é um sistema de microgeração fotovoltaica de 19,8 kWp instalado em um edifício público de ensino e o outro é uma usina fotovoltaica de grande porte de 3 MWp, ligada à rede elétrica e também localizada na ilha de São Vicente. O estudo inclui o dimensionamento, a simulação de operação da rede de distribuição da ilha de São Vicente na ausência e na presença de sistemas fotovoltaicos. São feitas análises financeiras a fim de determinar o tempo de retorno dos investimentos, o valor atual líquido e a taxa interna de retorno dos investimentos. Também é feito uma análise de sensibilidade financeira para avaliar a influência do custo do Wp instalado e da taxa de juros do financiamento sobre os parâmetros financeiros. Os resultados mostram que a implementação dos sistemas fotovoltaicos é atrativa em termos financeiros e técnicos. A instalação do sistema de microgeração provoca uma grande redução da energia adquirida junto à rede pela unidade consumidora. É mostrado também que a usina de grande porte notadamente não alterou os níveis de tensão de funcionamento da rede e proporcionou uma diminuição das perdas ativas do sistema.

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.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-24T19:07:44Z No. of bitstreams: 1 pedromachadodealmeida.pdf: 10367147 bytes, checksum: 04b7cf913c75cb9f82395bf7b9769825 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-25T15:25:19Z (GMT) No. of bitstreams: 1 pedromachadodealmeida.pdf: 10367147 bytes, checksum: 04b7cf913c75cb9f82395bf7b9769825 (MD5) / Made available in DSpace on 2017-04-25T15:25:19Z (GMT). No. of bitstreams: 1 pedromachadodealmeida.pdf: 10367147 bytes, checksum: 04b7cf913c75cb9f82395bf7b9769825 (MD5) Previous issue date: 2013-11-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A presente tese contribui para a análise, modelagem e projeto de controladores discretos de um sistema de geração fotovoltaico de 30 kWp conectado à rede elétrica sem filtros passivos. O conversor fonte de tensão (VSC) de interface é interligado a rede elétrica usando somente as indutâncias de dispersão de um banco de transformadores monofásicos como filtros harmônicos. Modelos discretos são desenvolvidos tanto para o lado CC quanto para o lado CA do conversor. A modelagem do lado CA foi feita nos sistemas de coordenadas αβ0 e dq0. Já a modelagem da dinâmica do lado CC foi feita no sistema de coordenadas dq de acordo com balanço de potência entre os terminais do VSC. Baseado nos modelos obtidos, duas estratégias básicas foram investigadas e discutidas para projetar os compensadores discretos usados para controlar as correntes sintetizadas por um sistema de geração fotovoltaico no modo de corrente. Resultados experimentais mostram que o uso apenas de controladores lineares, proporcional–integral (PI) e proporcional–ressonante (PR), sintonizados na componente fundamental não é suficiente para manter a qualidade das correntes geradas dentro dos padrões internacionais, devido a operação não linear do transformador de conexão. Para contornar o problema anterior duas soluções foram investigadas: (i) inclusão de múltiplos controladores ressonantes nas coordenadas αβ; e (ii) inclusão de um controlador repetitivo em paralelo com o controlador PI nas coordenadas dq. Resultados experimentais mostraram que ambas estratégias são adequadas para compensar as componentes harmônicas. Finalmente, foi proposta uma estratégia para controlar o conversor durante faltas assimétricas (Fault–ride through) e eliminar as oscilações no barramento CC durante condições de desbalanço. O controlador proposto é composto por uma parcela PI e duas parcelas ressonantes, as quais controlam as componentes média e oscilante, através da injeção correntes de sequencia positiva e negativa na rede, respectivamente. Resultados de simulação mostram que o controlador proposto é adequado para eliminar as oscilações no barramento CC sem prejudicar as estabilidade do sistema. / The current thesis contributes to the analysis, modelling and design of discrete time controllers which aim is to control a 30 kWp photovoltaic dispersed generation system connected to the electric grid without passive filters. In fact, the interface voltage– sourced converter (VSC) is connected to the grid using only the leakage inductance of a single–phase transformer bank as harmonic filters. Initially, discrete time models are developed to the converter’s DC–side as well as to the AC–side. The AC–side modelling is performed on αβ0 and dq0 coordinate systems. On the other hand, the DC–side dynamics are modeled on the dq frame according to the power balance between the converter’s terminals. Based on the models obtained, strategies to control the converter in the current mode control on the αβ and dq are developed and a methodology to design the controllers are addressed in details. Experimental results shown that only the use of linear controllers, proportional–integral (PI) and proportional–resonant (PR), tuned on the fundamental component are not sufficient to guarantee the quality of the generated currents according to international standards. This is due to the operation of the connection transformer in a nonlinear region. In order to overcome this drawback, two solutions are taken into account: (i) inclusion of several parallel resonant controller in αβ frame; and (ii) inclusion of a repetitive controller in parallel with the PI controller in the dq frame. Experimental results shown that both strategies are suitable to compensate the harmonic components on the output current. Finally, a strategy is proposed to control the system under asymmetrical faults (fault–ride through) and to mitigate the voltage oscillation on the DC–side during unbalance conditions. The proposed controller is composed of a PI part and two resonant parts, which controls the average and the oscillating voltage components, through the injection of positive and negative sequence currents into the grid, respectively. Simulation results shown that the proposed controller is suitable to mitigate the DC–side voltage oscillations without jeopardizing the system stability.

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.

As manufacturing is creating welfare and prosperity, it is important for humankind. Nevertheless, manufacturing is causing the depletion of natural resources, environmental burdens affecting the health of animals, humans and eco-systems, and social conflicts. Thus, it is essential to implement sustainability into manufacturing. Paint shops are however known for being liable for a big part of the large energy consumptions within manufacturing. Therefore, it is necessary to investigate what cost-effective solutions can be implemented in paint shops in order to reduce the energy consumption in a sustainable manner. Hence, the aim of this study was to, from a manufacturing perspective identify possible cost-effective solutions for lowering energy consumption within paint shops. The aim was further divided into two research questions: • RQ1: What are the enablers for energy efficient paint shops? • RQ2: What are the challenges for energy efficient paint shops? The research approach used to answer the aim and research questions were a literature review and a case study. The literature review was performed to get a deeper understanding of the subject and was then complimented with the findings from the case study. The case study was performed at the paint shop of a global automotive manufacturing company in Sweden, which currently have a high energy consumption. The enablers identified were (1) implementation of solar photovoltaic, and an energy storage system, which enables an environmentally friendly way of generating energy on-site and store excess energy for later use. The energy storage system can also be used to save money by utilizing the fluctuating electricity market prices, charging the battery when the energy price is at its lowest. (2) Implementation of an UV-curing system and paint, which is an environmentally harmless method of curing paint. (3) Reducing or disabling the heating, ventilation and air conditioning system of a building when it is not a necessity. (4) Workers commitment and motivation towards sustainability, to ensure everyone’s participation. The challenges identified were (1) the expensiveness of sustainability, allocating and prioritizing it in budgets is challenging for a company since profitability is always a major concern that often overshadows sustainability. (2) The risk of modifying the processes within the paint shop, as the consequences are unexplored. (3) In its current state, the energy consumption of the paint shop is very high, it is hence difficult to provide the whole paint shop with solely solar photovoltaic. (4) An energy storage system requires space and freeing up that space is a challenge without reconstructing existing facilities. (5) With implementation of UV- curing, the paint used must be curable with UV-light. Additionally, complex three-dimensional shapes make it challenging to properly cure evenly with UV-curing. (6) It is not guaranteed whether it is possible to completely shut down heating, ventilation and air conditioning since industrial equipment in general is designed to always run. (7) Sustainability is not a focus and even if it is increasingly requested by society, the commitment of companies is experienced as low. It is challenging to motivate all the employees to work towards sustainability and find ways to always keep sustainability in mind and to prioritize it over other alternatives.

The global climate and energy crisis has amplified the need for renewable energy sources, withsolar photovoltaic (PV) systems expected to play a significant role in the future energy mix. In this context, distributed energy systems (DES) are identified as part of the solution to address climate and energy challenges.With the increasing demand for photovoltaic energy sources, there is a growing requirement forefficient Business Case Tools (BCT) to analyze investments in distributed solar PV installations.A two-part model, consisting of a solar model and spot price data, was developed based onparameters such as solar radiation, location, angle, orientation, system losses, installedcapacity, and historical spot price data. The model was integrated with Power BI for investment calculations and visualization of results. The developed model provides approximations for solar PV system electricity production, which were validated against selected installations in allelectricity areas of Sweden. The validation revealed an average relative absolute error of 14.72 percent for the model. The conclusion drawn is that BCT can be utilized to analyze and visualize solar PV investments at specific locations in Sweden. The results indicate that Power BI, as a BCT, has limitations indynamic data collection but performs well in executing calculation of investments and visualizingthe results. Well-developed BCT can facilitate decision-making through real-time calculations and contribute to smoother implementation of distributed systems by providing detailed insightsinto their financial characteristics. Further research is needed to develop a model specificallytailored for distributed installations with storage capabilities. / Världen befinner sig i en global klimat- och energikris vilket ökat behovet av och efterfrågan på förnybara energikällor. Solceller förväntas utgöra en betydande del av den framtida energimixen. I kombination med detta identifieras distribuerade energisystem (DES) som endel av lösningen på klimat- och energifrågan. I takt med den ökade efterfrågan på fotovoltaiska energikällor ställs större krav på effektiva Business Case Tools (BCT) för att analysera investeringar i distribuerade solcellsanläggningar. En modell bestående av två delar, en solmodell och spotprisdata,utvecklades utifrån parametrarna solstrålning, plats, vinkel, riktning, systemförluster, installerad effekt samt historiska spotprisdata. Modellen sammankopplas med Power BI föratt utföra investeringskalkyler och visualisera resultatet. Den utvecklade modellen gerapproximationer för solcellsanläggningars elproduktion, vilket validerades mot utvaldaanläggningar i Sveriges samtliga elområden. Enligt valideringen uppgår modellens genomsnittliga relativa absoluta fel till 14,72 procent. Slutsatsen dras att BCT kan användas för att analysera och visualisera solcellsinvesteringar på specifika platser i Sverige. Resultatet visar att Power BI som BCT har brister när detkommer till dynamisk datainsamling, men genomför och visualiserar investerings kalkyler med enkelhet. Välutvecklade BCT kan användas för att underlätta beslutsfattande genomrealtidsberäkningar och kan bidra till en smidigare implementering av distribuerade systemgenom att belysa deras finansiella karaktär på ett detaljerat sätt. Fortsatt forskning krävs föratt ta fram en modell anpassad för distribuerade anläggningar med lagringsmöjligheter.