L’objectif de cette thèse est d’analyser l’apport des énergies renouvelables à la transitionénergétique dans les pays en développement (PED). L’apport des énergies renouvelables à latransition énergétique dans les pays en développement se justifie à deux niveaux. Dans unpremier temps il vise à étudier les conditions, moyens et conséquences de la modification desstructures de production énergétique existantes basées sur les technologies fossiles vers cellesintégrant les technologies propres qui sont plus respectueuses de la qualité de l’environnement.Dans un second temps, l’analyse de la transition énergétique propose une architectureinstitutionnelle, technologique, sociologique, réglementaire et managériale favorisant laconvergence vers un système socio-technique soutenable à travers la diffusion et l’adoption destechnologies renouvelables. Partant des approches existantes, l’idée fondatrice de cette thèse estd’insister sur la nécessité d’une mise en place d’une approche mixte de transition énergétiquedans les pays en développement en combinant une approche décentralisée (permettant de prendreen compte les caractéristiques spatiales des zones rurales enclavées) et centralisées (permettantd’insérer les PED dans un paradigme énergétique soutenable). A partir de cette orientation, nous!6proposons une approche interdisciplinaire empiriquement basée sur l’Afrique du Sud et leSénégal afin d’analyser l’apport des énergies renouvelables à la transition énergétique. Les outilsméthodologiques ont combiné la modélisation du type bottom-up et les techniques d’optimisationà travers les algorithmes de programmation linéaire. / The objective of this doctorate thesis is to investigate the contribution of renewable technologiesto energy transition in developing nations. In the theoretical framework such a contribution couldbe justified in two points. First, it analyses conditions, means and consequences of a modificationof a fuel-based energy production scheme to a new structure based on a more sustainableorientedpathway. Second, the analysis of energy transition provides institutional, technological,sociological and managerial frameworks strengthening the convergence toward a sustainableoriented energy paradigm through a diffusion and adoption of renewable technologies. From theexisting approaches, the core of this thesis is to assume a requirement to consider a mixedapproach of energy transition in developing nations through a combination of both decentralizedand centralized options. The decentralized energy transition approach allows an insertion ofspatial and geographical characteristics of remote locations in developing nations while thecentralized approach strengthens an inclusion of developing nations in a sustainable energyparadigm. From this orientation, we propose an interdisciplinary methodology, empirically basedon South Africa and Senegal in order to investigate the possible contribution of renewabletechnologies to energy transition. To investigate these questions, we combine a bottom-up energymodeling approach with optimization techniques through a linear programming algorithm.

This master thesis aims to examine the relationship between energy consumption and economic growth and between energy consumption and greenhouse emissions for the EU countries, using a panel time series data from 1996 to 2012 within a multivariate framework for 26 EU countries. The energies are composed from oil consumption, natural gas consumptions, and renewable energies including the biomass as a distinct part. To do that, Unit Root Tests, cointegration test, Pairwise Granger causality tests, and Error Correction Model are employed to find out the type of the causal relationship. The main results to denote are that, there is in the short run, a positive unidirectional causal relationship running from oil consumption to economic growth. We can as well denote a positive bidirectional causal relationship between renewable energies and economic growth and between greenhouse emissions and economic growth. However, there is an unexpected negative bidirectional causal relationship between biomass consumption and gas consumption. From the greenhouse emissions perspective, we can see in the short run, a negative bidirectional causal relationship between greenhouse emissions and renewable energies, and a positive unidirectional causal relationship running from both oil consumption and biomass consumption...

This project aims to make a comparison between the Swedish and Indianelectricity market, the design of new improvements will achieve a betteroperation for both markets as well as the price forecasting for markets. Thisresults will give a clear idea about the electricity prices, different energy uses andpeak hours and also the carbon dioxide emissions.Also the main organizations of the market and their roles has been characterized,discussing about the functions of the Market Operator and the System Operator.And also the different markets, the trading products and the price formation havebeen explained and giving an idea about the market structure with enough details.Moreover, Time Series Analysis explained in a detail manner and some of themost used methods in Time Series Analysis are also explained in a very goodmanner. Mainly the results section includes the description of the market situationin Swedish and Indian electricity markets comparison, which includes Powerinstalled capacity, electricity generation, main renewable technologies andpolicies to increase the renewable energy share in total electricity generated.After this analysis, the strengths and weakness of both markets are presented andthe main problems of Swedish electricity system like dependency for nuclearpower, uncertainty for solar electricity generation and the Indian electricitysystem problems like high losses in power system, power quality issues, and veryless focus on energy mix with renewable systems.Finally, due to the quick development of the energy sector in the last few yearsto reach a new design for the electricity market, different kinds ofrecommendations for the future have been considered.

La remise en question du mode de développement des sociétés humaines a, sur ces 40 dernières années, profondément transformé le contexte énergétique mondial, instaurant alors un nouveau cadre politique permettant l’essor spectaculaire des énergies renouvelables. Par ailleurs, si l’électricité apparaît comme un vecteur fondamental du développement humain, le contexte des populations majoritairement rurales d’Afrique subsaharienne incite à la recherche d’alternatives énergétiques adaptées. En substance, si les ressources renouvelables peuvent répondre de manière pertinente au défi de l’électrification décentralisée des zones rurales de la région, elles doivent également représenter une solution technique et économique crédible, avant d’être politique.La République de Djibouti, petit pays situé dans la corne de l’Afrique, symbolise parfaitement le défi socio-énergétique de l’ensemble de la région, et des populations rurales en particulier. Avec un pays pauvre en ressources traditionnelles mais présentant a priori un gisement solaire intéressant, nous avons alors privilégié l’étude des systèmes photovoltaïques (PV) dans le cadre de l’électrification décentralisée des populations rurales du pays. Comme d’autres ressources, ces systèmes, bien que reposant sur une technologie relativement ancienne, ont réellement pris leur essor au début des années 2000 avec les mesures incitatives du Protocole de Kyoto.Évaluer la pertinence de la technologie photovoltaïque nécessitait, dans un premier temps, d’estimer le niveau et la répartition de la ressource solaire au sein du pays. Pour cela, nous avons construit un atlas de l’irradiation solaire horaire incidente sur le territoire, pour la période 2008-2011, à partir d’un modèle satellitaire de rayonnement. Afin de valider les estimations issues de cet atlas, nous les avons comparées aux mesures in situ relevées par deux stations météorologiques temporaires déployées, entre 2010 et 2013, sur quatre sites présentant des caractéristiques distinctes. Finalement, la carte annuelle extraite de l’atlas a confirmé que le gisement solaire du pays, avec une irradiation moyenne de 5,87kWh/m² par jour, constituait l’un des plus importants au monde.Si les modèles utilisant des données satellitaires permettent de retrouver le flux solaire incident au sol, ils ne tiennent en revanche pas compte des effets du relief local sur ce dernier. Ainsi, afin de tenir compte des effets d’ombrage engendré par le terrain, nous avons développé une procédure dite de désagrégation, couplant l’utilisation d’un maillage numérique d’altitude aux cartes de rayonnement issues du modèle satellite. Pour ce faire, nous avons élaboré un modèle théorique pour retrouver l’horizon autour d’un point donné, et validé celui-ci à l’aide d’une campagne de mesures topographiques en Corse. En corrigeant ensuite le rayonnement à l’aide de cet horizon pour chaque pixel du maillage d’altitude, nous avons pu enrichir le niveau de l’information fournie par la cartographie de l’irradiation globale.Bien que le gisement solaire soit l’indicateur principal du potentiel photovoltaïque, il est également nécessaire de considérer des paramètres secondaires, éléments de technologie et caractéristiques environnementales, qui permettent d’évaluer avec précision l’énergie électrique produite par un système PV quelconque. En combinant l’utilisation de différents modèles, nous avons ainsi pu intégrer à l’estimation finale du productible l’influence du rayonnement et de la température sur le rendement de conversion d’un module photovoltaïque. Nous avons ainsi construit une cartographie du productible PV qui, couplée à une évaluation multicritère de la pertinence de la technologie PV vis-à-vis des alternatives énergétiques classiques en matière d’électrification rurale, est destinée à faciliter la prise de décision pour les différents acteurs, publics ou privés, du domaine de l’énergie. / Over the 40 past years, growth of renewable energies benefited of the new world energy frame, which resulted of the questioning about what development of human societies had to be. Furthermore, although human development comes with electricity, the rural condition of many populations of sub-Saharan Africa incites us to look for suitable power supply alternatives. Eventually, in this specific context, renewable energies can represent a reliable solution to the off-grid electrification of rural peoples. However, this solution has to be economical and technical, and not only political.The Republic of Djibouti is a little developing country located in the Horn of Africa which perfectly symbolizes the social and energy challenges of rural populations in Sub-Saharan Africa. Instability and limitation of the existing electrical grid, fuel cost and lack of fossil resources point to the geographically diffused solar resource as probably the best way to improve human development and reduce poverty of Djiboutian rural peoples. Therefore, we have considered the study of photovoltaic (PV) systems within the rural off-grid electrification frame.Firstly, in order to evaluate relevance of these systems, it was necessary to estimate level and repartition of the solar resource across the country. So we developed a solar atlas, i.e. cartography of the hourly solar irradiation reaching the ground, based on satellite-derived irradiance estimates retrieved between 2008 and 2011. For assessing the atlas quality, we compared irradiation estimates with ground measures retrieved on 4 different sites by 2 temporary weather stations deployed between 2010 and 2013. Finally, yearly map extracted from the atlas showed that, with a daily mean irradiation of 5,87kWh/m².day, the solar potential of Djibouti is one of the most significant in the world.Satellite models are useful for determining solar irradiance at ground level but they don’t take into account local topography effects. In order to incorporate these shading effects to the satellite-derived irradiance maps, and so improve irradiance accuracy and spatial resolution, we used a Digital Elevation Model (DEM). Firstly, this disaggregation process was based on the development of a new fast horizon algorithm which was assessed by means of topographic measures in Corsica Island. Then, by correcting irradiance with this horizon for each pixel of the DEM, we improved geographic information of the solar irradiation atlas.Although solar resource is the first indicator of the photovoltaic potential, other elements, as environmental parameters or endogenous characteristics of photovoltaic modules, also have to be taken into consideration for precisely estimating energy produced by a PV system. Hence, by means of different models, we evaluated influence of irradiance and temperature onto the conversion efficiency of a PV generator to finally retrieve the atlas of the PV potential across the country. In conclusion, by combining this cartography to a multi-criteria approach comparing relevance between PV systems and classical power supply systems within the rural electrification scheme, we developed the first photovoltaic decision making tool of the country intended for all officials who are acting in the energy field.

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

The importance of utilizing different types of energy and their technical application is discussed. Awareness around the globe about the world energy crisis and its critical environmental condition has put more emphasis on the use of renewable energies in every corner of life. It is a well‐known fact that global warming, inefficient use of energy and greenhouse gases are damaging the environment, species and human life drastically. These issues will be discussed in recently conducted research. To address the crucial state of our environment, two simultaneous scenarios are considered. Initially, energy conservation and the switch to a low carbon/no carbon fuel are studied. As for energy conservation in buildings, smart methods in the use of energy in buildings are discussed. Based on different research reported, humans must change their attitude toward the use of resources, and in particular, be conscientious about energy consumption. Next, renewable energy promises a suitable alternative to energy needs in this century, and the best means to overcome the environmental issue and energy crisis is discussed. The practical methods of calculation for solar technology equipment, ground source heat pumps, and wind turbines are explained. In the application part of the study, four buildings are chosen as case studies; two of them from residential sectors, one is a commercial/institutional building, and the fourth is an industrial building. A ground source heat pump for heating and cooling, a solar water heater for heating space or hot water, and a photovoltaic panel for generating electricity are designed for the case studies. Even projects under hybrid systems combined from two technologies are designed. 36 different energy options are calculated for the four case studies. Results show that if a target is reducing CO2 emissions, what systems are the best. In contrast, when decision making is based on budget, what system is the first choice? Not only are technology, environmental protection and cost the main parameters for deciding on renewable technologies, but so are reliability, installation, maintenance and ease of use. Hence, renewable energy systems are categorized based on a broad vision.

This research has generated interesting findings from the inductive approach and the qualitative methods that were used in the inquiry process. Thanks to the literature review, the semi-structure interviews, a focus group and secondary data it was possible to obtain the necessary information to answer the research question: How do ecological, economic and social sustainability influence employee motivation? In order to answer this question, two sub-questions were considered first, namely What constitutes sustainability in the company-specific context of Wagner & Co Solartechnik? and Does sustainability motivate people? The answer to the latter question has to be yes, as the analysis revealed numerous linkages. From the data gathered, it is apparent that economic sustainability constitutes the most basic level of sustainability at Wagner Solar. Although the influence of money has its clear limitations, an increase in material orientation could be observed compared to previous. At the company level, ecological sustainability manifests itself as ‘striving for the energy turnaround’. The majority of employees show, as their most important source of motivation, an interest in solar technology as well as a concern for increased eco-efficiency. The information gathered has permitted an assessment of whether the company hires people that are already committed to the company’s vision and mission, or whether the company makes an effort to socialise employees. While this does not seem to be the case it is apparent that the company cultivates a communication and information policy that perpetuates its values. Wagner Solar also exhibits a strong and consistent corporate culture. In terms of social sustainability, democratic decision-making appears to exert the greater amount of influence on employee motivation, while the influence of employee ownership is comparatively diminished. The company appears to both attract and seek out employees who value the ability to work autonomously, partially explained by the German nationality but not exclusively. Positive work environment and good collaborations between colleagues were deemed another important motivational factor, both by the interviewees and the intra-company survey. However, working at Wagner Solar is not without its perceived negatives. These are mostly related to the company’s unique decision-making structures, the use of the language, and possible “island” mentality that some departments might suffer. The study also aimed to analyse the influence of different motivators on employees. When contemplating which pillars of sustainability motivate the most, the analysis of the main motivators revealed that the most important pillar is the social one, since most of the participants have one or more main motivators connected to it. Overall, the impression is that the social values of Wagner Solar are the most pervasive, affecting attitudes and behaviours such as autonomy and responsibility, and, therefore, constitute the main motivators for its employees. The ecological pillar also noticeably influences employee motivation, while the economic pillar is the least influential. / MSPME - Masters in Strategic Project Management European

Le but de cette thèse est le développement et l'optimisation de la chaine électrique d'une hydrolienne fluviale. L'approche est d'abord traitée en simulation pour ensuite finir par la conception et la mise au point d'un prototype. La partie simulation concerne la modélisation des ensembles turbines, génératrices et électronique de puissance mais aussi le développement des diverses lois de commandes. Ces commandes peuvent intervenir à différents niveaux du contrôle jusqu'à la supervision complète du système, permettant de gérer des défauts, des algorithmes de MPPT (extraction maximale de puissance), des synchronisations entre colonne, ... Le prototype d'hydrolienne fluviale sera ensuite présenté, de la mise au point des parties mécaniques jusqu'aux résultats expérimentaux. Les travaux nombreux autour de ce prototype ont permis d'obtenir des résultats satisfaisants et encourageants qui corroborent la théorie. / The purpose of this thesis is the development and optimization of the electrical system of a fluvial cross-flow current turbine. The approach is first treated in simulation and then eventually with the design and development of a prototype. The simulation section deals with the modeling of turbines groups, generators and power electronics, as well as the development of various control laws. These controls may have an influence at different levels of the control strategies up to the complete system supervision for fault management, MPPT (maximum power extraction) algorithms, turbine columns synchronization... The fluvial cross-flow current turbine prototype will then be presented, from the development of the mechanical parts to the experimental results. The various works involving the prototype have yielded satisfactory and encouraging results that corroborate the theory.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Because of the lack of drinkable water in various semi-arid regions and the necessary use of renewable energies, the present work presents a performance study of a heat recovery tower to operate in a solar desalination unit for decentralized water production. The solar desalination unit has two parts: a heating unit and a desalination unit.This work presents the field results with a desalination tower with synthetic (polyurethane) flow channels. The tower operation consists of the heating of salty water, the evaporation of desalinated water vapor in the lower stage, and the vapor condensation on the above stage. The condensate flows to a lateral channel to be collected, while the salty water in the trays is heated by the heat transfer processes, particularly the condensation from the tray below. The heating, evaporation, and condensation processes are repeated among the trays in a heat recovery mechanism. The results also show the correlation parameters for the Sherwood number, developed using the experimental data gathered in a temperature controlled laboratory desalination unit. This correlation was used as a reference in the study of heat recovery towers. The solar dealination system is working properly and showed a daily production of 35 liters. The results present the production per stage and the temperature profiles, in graphical form. For the performance parameters, a GOR value of 1,26 and a COP value of 4,78 were measured. The Sherwood correlation was used to compare experimental and simulated values. / Diante da crescente escassez de Ãgua potÃvel em vÃrias regiÃes semi-Ãridas, e a necessidade de avanÃo na utilizaÃÃo de fontes de energias renovÃveis, o presente trabalho apresenta o estudo do desempenho de uma torre de recuperaÃÃo de calor para operar com um dessalinizador solar que possa ser utilizado para a produÃÃo descentralizada de Ãgua potÃvel. O dessalinizador solar estudado possui duas unidades bÃsicas: a unidade de aquecimento e a unidade de dessalinizaÃÃo. O trabalho apresenta os resultados alcanÃados com uma torre de recuperaÃÃo de calor com canais sintÃticos de poliuretano. A operaÃÃo da torre consiste no aquecimento e evaporaÃÃo de Ãgua salobra armazenada em um estÃgio inferior, que condensa na parte inferior da bandeja do estÃgio acima. O condensado escoa para uma calha lateral de onde à coletado, enquanto a Ãgua armazenada na bandeja à aquecida devido aos processos de transferÃncia de calor, pricipalmente ao processo de condensaÃÃo. O processo de evaporaÃÃo, condensaÃÃo e aquecimento de Ãgua se repete entre as bandejas contidas nos estÃgios da torre de recuperaÃÃo de calor, em um total de cinco estÃgios. Os resultados apresentam ainda os coeficientes de uma correlaÃÃo para o nÃmero de Sherwood, desenvolvida a partir de uma unidade de dessalinizaÃÃo de laboratÃrio, operando em temperaturas controladas, para ser usada como modelo de referÃncia na determinaÃÃo do desempenho de torres de recuperaÃÃo de calor. O dessalinizador està em funcionamento e a torre de recuperaÃÃo de calor apresentou bons resultados alcanÃando uma produÃÃo de 35 litros de Ãgua dessalinizada por dia. Os resultados da produÃÃo por estÃgio e dos perfis de temperatura do dessalinizador estÃo apresentados na forma de grÃficos. Os parÃmetros de desempenho foram calculados e alcanÃados os valores de 1,26, para o GOR do dessalinizador e 4,78 para o COP. A correlaÃÃo para o nÃmero de Sherwood foi desenvolvida e foram comparados os valores experimentais com os valores obtidos pela correlaÃÃo.

This report aims to make a comparison between the Swedish and Spanish electricity market, the design of new improvements that could achieve a better operation for both markets as well as the price forecasting for both spot markets. These enhancements are oriented to decrease electricity prices, energy use and the system CO2 emissions. Also, the main organizations of the market and their roles has been characterized, clarifying the functions of the Market Operator and the System Operator. In addition, the different markets, the trading products and the price formation have been explained and the picture of the market structure has been achieved with enough depth. Moreover, some of the most used methods in Time Series Analysis has been enumerated to understand which techniques are needed for forecast the electricity prices and the methodology used (Box-Jenkins Method) has been explained in detail. Later, all these methods have been implemented in an own code developed in Python 3.6 (TSAFTools .py) with the help of different statistics libraries mentioned during the method chapter. On the other hand, the description of the market situation has been carried out for both countries. Power installed capacity, electricity generation, average prices, main renewable technologies and policies to increase the renewable energy share has been analysed and corresponding described. Then, to estimate the market’s future spot electricity prices, ARIMA models have been selected to analyse the evolution of the day-ahead price using the TSAFTools.py. The final models show a proper performance in the two markets, especially in the Nordpool, achieving an RMSE: 37.68 and MAPE: 7.75 for the year in 2017 in Nordpool and a RMSE: 270.08 and MAPE: 20.24 in OMIE for 2017. Nordpool spot prices from 2015 to 2016 has been analysed too but obtaining a result not as good as the year 2017 with an RMSE: 49.01 and MAPE: 21.42. After this analysis, the strengths and weaknesses of both markets are presented and the main problems of the Spanish electricity system (power overcapacity, fuel dependency, non-cost-efficient renewable energies policies, lack of interconnexion capacity etc.) and the Swedish electricity system (dependency for nuclear power, uncertainty for solar electricity Generation) are presented. Finally, due to the quick development of the energy sector in the last years and the concern of the European Committee to reach a new design for the electricity market, different kinds of recommendations for the future have been considered.