In the pursuit of a cleaner and sustainable environment, solar photovoltaic (PV) power has been established as the fastest growing alternative energy source in the world. This extremely fast growth is brought about, mainly, by government policies and support mechanisms world-wide. Solar PV technology that was once limited to specialized applications and considered very expensive, with low efficiency, is becoming more efficient and affordable. Solar PV promises to be a major contributor of the future global energy mix due to its minimal running costs, zero emissions and steadily declining module and inverter costs. With the expanding practice of managing decentralized power systems around the world, the role of private investors is increasing. Thus, the perspective of all stakeholders in the power system, including private investors, has to be considered in the optimal planning of the grid. An abundance of literature is available to address the central planning authority’s perspective; however, optimal planning from an investor’s perspective is not widely available. Therefore, this thesis focuses on private investors’ perspective. An optimization model and techniques to facilitate a prospective investor to arrive at an optimal investment plan in large-scale solar PV generation projects are proposed and discussed in this thesis. The optimal set of decisions includes the location, sizing and time of investment that yields the highest profit. The mathematical model considers various relevant issues associated with PV projects such as location-specific solar radiation levels, detailed investment costs representation, and an approximate representation of the transmission system. A detailed case study considering the investment in large-scale solar PV projects in Ontario, Canada, is presented and discussed, demonstrating the practical application and usefulness of the proposed methodology and tools.

With the ever-growing energy demand that world is currently going through and the danger of climate change around the corner, wagering in renewable energy seems to be the right path to create a more smart and green future. Sweden has put great effort on decreasing its dependency on oil, in fact in 2012 more than 50 % of its electricity came from the renewable source and has a plan in making it 100 % in 2040. However, when it comes to heating systems Sweden depends greatly on district heating, and situations which buildings are located outside the district heating system’s reach is not uncommon, hence for those buildings, other options such as solar power or heat pumps are considered. Many buildings located in Skutskär suffer from the problem stated above. The particular building analyzed in this thesis uses electrical radiator and furnace as sources of heat, which implies high energy uses and financial expenses. For this reason technical and financial analysis of using each alternative system for a single family house located in Skutskär had been done. Using solar powered system is deemed to be quite ineffective, as Sweden has poor solar radiation. In order to compensate the poor sun hours during the winter, 51 photovoltaic (PV) panels or 19 solar thermal panels would be required. This high initial investment needs long period of time in order to be profitable, 15 years for solar thermal system and 21 years for solar PV system. On the other hand, the results from the heat pumps are quite satisfactory, the fastest payback period is around 4 years. This is achieved by using air source heat pump (ASHP), the annual saving in this case is three times higher than using solar photovoltaic panels, making the usage of ASHP more attractive than any solar energy system. However, when annual saving is concerned, the ground source heat pump (GSHP) system is capable of generating even higher saving, but the initial investment is significantly higher, extending the payback period to 6 years.

abstract: Improving the conditions of schools in many parts of the world is gradually acquiring importance. The Green School movement is an integral part of this effort since it aims at improving indoor environmental conditions. This would in turn, enhance student- learning while minimizing adverse environmental impact through energy efficiency of comfort-related HVAC and lighting systems. This research, which is a part of a larger research project, aims at evaluating different school building designs in Albania in terms of energy use and indoor thermal comfort, and identify energy efficient options of existing schools. We start by identifying three different climate zones in Albania; Coastal (Durres), Hill/Pre-mountainous (Tirana), mountainous (Korca). Next, two prototypical school building designs are identified from the existing stock. Numerous scenarios are then identified for analysis which consists of combinations of climate zone, building type, building orientation, building upgrade levels, presence of renewable energy systems (solar photovoltaic and solar water heater). The existing building layouts, initially outlined in CAD software and then imported into a detailed building energy software program (eQuest) to perform annual simulations for all scenarios. The research also predicted indoor thermal comfort conditions of the various scenarios on the premise that windows could be opened to provide natural ventilation cooling when appropriate. This study also estimated the energy generated from solar photovoltaic systems and solar water heater systems when placed on the available roof area to determine the extent to which they are able to meet the required electric loads (plug and lights) and building heating loads respectively. The results showed that there is adequate indoor comfort without the need for mechanical cooling for the three climate zones, and that only heating is needed during the winter months. / Dissertation/Thesis / Masters Thesis Architecture 2015

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Nowadays, the distribution networks of electricity are the segment of the electrical power systems that has experienced more changes, due in particular to the presence of distributed generation and the technological advances in the areas of instrumentation, automation, measurement, information technology and comunication. This work aims to present the modelling, the control and the operation management of a group of small-scale energy resources connected to the low voltage, which coordinated form a microgrid. The microgrid energy resources are solar photovoltaic sources, wind energy based on double fed induction generator and hydrogen fuel cell, and a storage system with batteries. Two conceptions are developed: a single-phase microgrid and a three-phase microgrid, both operating in connected mode and isolated from the utility. Each energy resource is connected to a point of common coupling through power converters. For each converter was designed a set of control loops. The master-slave strategy was used to control the converters and to microgrid management. In master-slave configuration only the master converter is designed to be the voltage reference and others operate as a current source. For managing the steady state operation of microgrids different operating scenarios were considered, with variation of load and generation levels, as well as changes in tariff flags, for load supply with economy and sources operating at maximum efficiency. The proposed systems operate satisfactorily fulfill the requirements of utility for synchronization and disconnection. The injected currents are below the allowed distortion level. In stand-alone mode, the system voltage remains within the appropriate level of amplitude and frequency. / Atualmente, as redes de distribuiÃÃo de energia elÃtrica sÃo o segmento dos siste-mas elÃtricos de potÃncia que mais tem experimentado mudanÃas, devido, em es-pecial, à presenÃa da geraÃÃo distribuÃda e aos avanÃos tecnolÃgicos nas Ãreas de instrumentaÃÃo, automaÃÃo, mediÃÃo, tecnologia da informaÃÃo e comunicaÃÃo. Este trabalho tem por objetivo apresentar a modelagem, o controle e o gerenciamento da operaÃÃo de um conjunto de recursos energÃticos de pequeno porte, conectados à baixa tensÃo, que coordenados formam uma microrrede. Os recursos energÃticos da microrrede sÃo fontes solar fotovoltaica, eolielÃtrica com gerador de induÃÃo de dupla alimentaÃÃo e cÃlula combustÃvel a hidrogÃnio, e um sistema de armazenamento de energia a baterias. Duas concepÃÃes de microrredes sÃo desenvolvidas: microrrede monofÃsica e microrrede trifÃsica, ambas operando em modo conectado e isolado da rede elÃtrica principal. Cada recurso energÃtico à conectado a um ponto comum de conexÃo atravÃs de conversores de potÃncia. Para cada conversor foi projetado um conjunto de malhas de controle. A estratÃgia mestre-escravo foi usada para o controle dos conversores e gerenciamento da microrrede. Na configuraÃÃo mestre-escravo apenas o conversor mestre à designado para ser a referÃncia de tensÃo que os outros conversores necessitam para operarem como fonte de corrente. Para o gerenciamento da operaÃÃo das microrredes em regime permanente, foram considerados diferentes cenÃrios de operaÃÃo, com variaÃÃo de nÃveis de carga e de geraÃÃo, bem como variaÃÃo de bandeiras e postos tarifÃrios, visando atender a carga com economicidade e fontes operando em mÃxima eficiÃncia. Os sistemas propostos operam de forma satisfatÃria obedecendo aos requisitos da concessionÃria para a sincronizaÃÃo e desconexÃo. As harmÃnicas de corrente injetada estÃo abaixo do nÃvel de distorÃÃo permitido. No modo isolado, a tensÃo dos sistemas permanece dentro do nÃvel adequado de amplitude e frequÃncia.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This dissertation presents the combination of an electrical and thermal model to represent the characteristics of the photovoltaic module floating in water. Based on the proposed model a MATLAB / Simulink software simulation is made and validated with data obtained through a experiment performed. Two experiments were conducted in the UFC Alternative Energy Laboratory in order to validate the model proposed by the use of two distinct manufacturing photovoltaic modules, a monocrystalline produced by Azur Solar GmbH model TSM 160M and a polycrystalline produced by Solartec model KS20T. The model proposed was satisfactory compared the model results with measured data, which is irradiance, temperature front, rear and IV characteristic curve of the PV module. The irradiance is obtained by a pyranometer LP02 model Hukseflux manufactured by Thermal Sensor, temperatures were measured with temperature sensors type thermo EN 100 and the characteristic curves were obtained by tracer curve mini-KLA, manufactured by IngenieurbÃro. The monocrystalline module errors were lower than 4% for short-circuit current values, open circuit voltage and maximum power point. To reduce the error the electric model initially proposed was changed at the point of maximum power and were obtained errors lower than 2% for the short-circuit current values, open circuit voltage and maximum power point. The polycrystalline module showed errors lower than 10% for the short-circuit current values, open circuit voltage and maximum power point. The polycrystalline module floating in water performance was compared to the conventional use (installed on the ground), being recorded a cell temperature difference at any given time of day to 29 ÂC between the two applications; as a consequence, better efficiency was obtained floating on the water module with power gains of up to 17% compared to conventional usage. / Esta dissertaÃÃo apresenta a combinaÃÃo de um modelo elÃtrico e tÃrmico para representar as caracterÃsticas do mÃdulo fotovoltaico flutuante em Ãgua. A partir do modelo proposto à realizada simulaÃÃo no software MATLAB/Simulink e validado com dados obtidos atravÃs de experimento realizado. Foram realizados dois experimentos no LaboratÃrio de Energias Alternativas da UFC a fim de validar o modelo proposto atravÃs da utilizaÃÃo de dois mÃdulos fotovoltaicos de caracterÃstica de fabricaÃÃo distintas, um monocristalino da Azur Solar GmbH modelo TSM 160M e um policristalino da Solartec modelo KS20T. O modelo proposto mostrou-se satisfatÃrio quando comparado os resultados do modelo com os dados medidos, que sÃo irradiÃncia, temperatura frontal, posterior e curva caracterÃstica I-V do mÃdulo fotovoltaico. A irradiÃncia à obtida atravÃs do piranÃmetro modelo LP02 do fabricante Hukseflux Thermal Sensor, as temperaturas foram medidas com sensores de temperatura tipo termorresistÃncia PT 100 e a curvas caracterÃsticas foram obtidas atravÃs do traÃador de cuva mini-KLA, do fabricante IngenieurbÃro. O mÃdulo monocristalino apresentou erros inferiores a 4% para os valores de corrente de curto-circuito, tensÃo de circuito aberto e ponto de mÃxima potÃncia. Visando diminuir o erro alterou-se o modelo elÃtrico proposto inicialmente no ponto de mÃxima potÃncia e foram obtidos erros inferiores a 2% para os valores de corrente de curto-circuito, tensÃo de circuito aberto e ponto de mÃxima potÃncia. O mÃdulo policristalino apresentou erros inferiores a 10% para os valores de corrente de curto-circuito, tensÃo de circuito aberto e ponto de mÃxima potÃncia. Observou-se o rendimento do mÃdulo policristalino flutuante em Ãgua em relaÃÃo ao uso convencional (instalado sobre o solo), sendo registrada uma diferenÃa de temperatura da cÃlula em determinado horÃrio do dia de atà 29ÂC entre as duas aplicaÃÃes; como consequÃncia, obteve-se melhor eficiÃncia do mÃdulo flutuante em Ãgua com ganhos de potÃncia de atà 17% em relaÃÃo ao uso convencional.

The existing environmental threats and the ever increasing global dependence on electric power highlight the importance of producing power in a sustainable manner. In accordance, it is vital to attract investments in electricity generation projects based on renewable energy sources, also called renewable energy projects (REP). This poses a challenge, as REP tend to be less financially competitive than their fossil fuel based counterparts. Moreover, the power grid has to be upgraded to integrate large amounts of RESs in an efficient and economic manner. An appealing alternative to enhance the financial appealing of REP is to improve the techniques used for their assessment. These tools produce robust and economically sound assessments, but tend to undervalue REP and other projects under uncertainty, as they neglect the flexibility of the projects to be adjusted in response to uncertainty. This can be corrected by extending the tools with the aid of real options (RO) theory. RO theory can be used to extend assessment techniques to value flexibility derived from the projects, their management, and even their environment, which can be used to enhance the financial value of REP in the changing power sector. In addition, the scope of RO theory is increasing to address flexibility in the design of the projects. Therefore, the theory can drive investments in REP and motivate the design of more profitable projects. This research project seeks to analyse the potential of RO theory to increase the financial worth of different types of REP in the current and changing power sector. The novelties of this research are that it expands RO theory by addressing the flexibility within the design of the projects, the potential of RO theory to manage uncertainties that are exclusive to the projects or typical in the power sector, and other relevant areas of research interest. The research produced several RO methodologies to model the planning, operation, and design of hydropower projects, wind power projects, and solar photovoltaic projects in existing power sector environments and environments characterised by high penetration of RESs and consumers with demand response capabilities. The results demonstrate the applicability of RO theory to enhance the financial value of different types of REP under a wide range of circumstances.

abstract: The availability of data for monitoring and controlling the electrical grid has increased exponentially over the years in both resolution and quantity leaving a large data footprint. This dissertation is motivated by the need for equivalent representations of grid data in lower-dimensional feature spaces so that machine learning algorithms can be employed for a variety of purposes. To achieve that, without sacrificing the interpretation of the results, the dissertation leverages the physics behind power systems, well-known laws that underlie this man-made infrastructure, and the nature of the underlying stochastic phenomena that define the system operating conditions as the backbone for modeling data from the grid. The first part of the dissertation introduces a new framework of graph signal processing (GSP) for the power grid, Grid-GSP, and applies it to voltage phasor measurements that characterize the overall system state of the power grid. Concepts from GSP are used in conjunction with known power system models in order to highlight the low-dimensional structure in data and present generative models for voltage phasors measurements. Applications such as identification of graphical communities, network inference, interpolation of missing data, detection of false data injection attacks and data compression are explored wherein Grid-GSP based generative models are used. The second part of the dissertation develops a model for a joint statistical description of solar photo-voltaic (PV) power and the outdoor temperature which can lead to better management of power generation resources so that electricity demand such as air conditioning and supply from solar power are always matched in the face of stochasticity. The low-rank structure inherent in solar PV power data is used for forecasting and to detect partial-shading type of faults in solar panels. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

This paper presents a mathematical sizing algorithms of a stand alone and grid-connected photovoltaic-battery system for a residential house. The objective is to minimize the total storage capacity with cost of electricity. The proposed methodology is based on a Linear and Non-linear programming involving a real data collected through one year with reference to Hradec Kralove meteorological data and typical load profile in Czech Republic. The algorithm jointly optimizes the sizes of the photovoltaic and the battery systems by adjusting the battery charge and discharge cycles according to the availability of solar resource and a time-of-use tariff structure for electricity. The results show that jointly optimizing the sizing of battery and photovoltaic systems can significantly reduce electricity imports and the cost of electricity for the household. However, the optimal capacity of such photovoltaic battery varies strongly with the electricity consumption profile of the household, and is also affected by electricity and battery prices.

This paper presents a mathematical sizing algorithms of a grid-connected photovoltaic-battery system for a residential house. The objective is to minimize the total storage capacity with cost of electricity. The proposed methodology is based on a Linear and Non-linear programming. We have presents results from a existing PV panel FS-4115-3 for the given climatic conditions and the electricity use profile. Measurements for whole household electricity consumption have been obtained over a period of two months. They were all obtained at one hour interval. The algorithm jointly optimizes the sizes of the photovoltaic and the battery systems by adjusting the battery charge and discharge cycles according to the availability of solar resource and a time-of-use tariff structure for electricity. The results show that jointly optimizing the sizing of battery and photovoltaic systems can significantly reduce electricity imports and the cost of electricity for the household.

The global photovoltaic (PV) market is growing, contributing to reduced climate emissions from electricity production. Historically, PV deployment mainly occurred in developed and electrified countries with a high level of certainty over their electrical system. Recently, this trend has started to change, contributing to a more globally distributed PV market. In primarily two of the emerging markets, Africa and the Middle East, the statistical situation is weak or non-existent, making it hard to monitor and track the PV development. PV devices can be grid-connected or off-grid, installed in PV parks or in smaller household applications, which further complicates the monitoring. As a result, the best available statistics on these markets, provided by the International Renewable Energy Agency (IRENA), are to a major part based on estimations not built on any official data.  In a pilot study a instrument prototype, Njord, for converting monetary trade data of PV devices into installed PV capacities was initiated, with the aim to provide more accurate estimates for these markets. Njord is in this study further developed, by increasing its resolution and adjusting assumptions. Further, an additional conversion factor, namely PV module weight, is implemented to improve the accuracy of the predictions. The time frame of Njord is enlarged enabling estimates of accumulated capacities, in contrast to previously only annual installations. The instrument methodology is based on a bottom-up approach of processing import and export customs data, and converting the data to installed capacities using the price and weight of a PV module per wattage. In addition to the further development of Njord, the trade data is used to map and analyse monetary trade flows and thereby market values. Identified improvements concerned, among others, to adjust the percentage of PV modules in the customs code for countries without specific codes, and to fill data gaps with additional mirror data. The weight conversion factor was initially implemented as a parallel instrument to the price based. The two conversion factors were then combined into an instrument choosing the most suitable conversion factor with regards to a number of constraints. The instrument performance was validated against reference countries with well documented PV markets, qualitatively customs data, and small domestic PV manufacturing. For the reference countries and the comparative period of 2016 – 2018, the total deviations were improved from spanning 11.1 % – 17.0 % to 0.5 – 22.6 %. The best performance is seen for the most recent years of 2018 and 2019, with total deviations of 0.5 % and 4.1 % respectively. Njord shows high performance for estimating accumulated capacity, with a deviation of 4.3 % in the end of 2019. When applying Njord to the markets of interest, Africa and the Middle East, the results are significantly higher than the IRENA estimates, with a result of 118 % higher for Africa and 127 % higher for the Middle East. This indicates that the PV deployment in these emerging markets could be underestimated in today's statistical situation.  In combination with the instrument results, mapping trade flows has shown to give comprehensive information about the PV markets of interest and shows the potential of using trade data for this type of analysis. China distinguishes as the dominant trade partner for both Africa and the Middle East, in line with the global PV market. Although these markets are small relative the global PV context, there was in 2019 still a net import of PV modules of in total 879 million US$ for Africa and 728 million US$ for the Middle East, and the markets are growing fast. Further, mapping trade flows has shown to identify manufacturing countries on the markets of interest, which there also is a lack of information on. The trade patterns and its inherent monetary values could be used to for example identify market development and business opportunities.