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The thesis is focused on an analysis of operational and the economic indicators of belt dryer for agricultural commodities and factors which influence these indicators. In company Agros Haná s.r.o. had measured three consecutive dryings of corn for gains on a dryer line (years 2016, 2017, 2018). On the basis of the measured values were established the energy consuptions and the operating costs of a dryer for each of the years. In additional, the individual factors influencing the amount of drying costs were analysed. The humidity of the corn during harvest proved to be one of the main factors, the temperature of drying dependant on the ambient air temperature was determined to be another decisive factor.

Cílem práce je zanalyzovat oblast nástrojů hospodářské politiky v oblasti obnovitelných zdrojů energie, srovnat s německými nástroji a zhodnotit, zda je podpora dostačná k zvyšování využívání obnovitelných zdrojů energie. Součástí práce je i případová studie bioplynové stanice a navržení opatření, která by měla pozitivní vliv na vývoj v této oblasti.

Master's Thesis considers the idea of use of renewable energy sources for the generation of electricity. On the basis of reports on climate warming, the European Union took measures, which are mandatory for all Member States and aimed to increase the share of renewable energy in total energy production by 2010. Czech Republic has committed itself to produce 8% of energy from renewable energy sources, the government has created a system of subsidies to renewable energy sources and a system of redemption prices. These measures make energy very expensive. This work deals with the origin of these measures, which are reports on global warming. My work is also comparing predictions on the future status, as well as examining the advantages of investing in renewable energy sources and comparing the prices of subsidized energy with other types of energy.

Diploma thesis Building and Operation of Biogas Stations and Theirs Impacts on Local Development from the Perspective of the Municipality´s Residents – A case study of Velké Albrechtice deals with the impact of the operation of biogas stations in the municipality of Velké Albrechtice on local development from a perspective of local residents. As a part of this work, a questionnaire survey and analysis of biogas stations in the municipality were carried out. The theoretical part is based on an identification of energy sources and their division. More attention is paid to renewable energy sources, respectively to secondary energy sources. It also focuses on establishing of the concept of biogas plants, theirs functioning, advantages and disadvantages. In addition, it describes problems and conflicts with the establishment of biogas plants. The practical part of the thesis presents the case locality - the municipality of Velké Albrechtice and specific biogas stations. Additionally, it evaluates opinions and attitudes of the local population towards these stations both before going to production and at present. It also includes an analysis of the results of the questionnaire survey and discussion about it. The output of the thesis is a comparison of the situation in the initial period of conflicts and current problems with the functioning of biogas stations. Moreover, it inquires whether there have been any changes both from the perspective of residents and in the operation of the stations. Reasons of these changes are evaluated at the discussion of the thesis. Next, the most significant positive and negative effects of the construction and operation of the biogas plant on the life of the community and its development are identified. Last but not least, the thesis conclusion formulates recommendations that can improve the future development of biogas plants in the Czech Republic and can prevent conflicts between biogas plant operators and the local population in other locations.

Dans un contexte de réduction des émissions de gaz à effet de serre et de raréfaction des ressources fossiles et fissiles, l'énergie solaire est l'une des sources d'énergie les plus prometteuses. La quantité d'énergie renouvelable dans le futur paysage énergétique dépend de sa disponibilité, de son coût et de son niveau d'efficacité. Plusieurs enjeux limitent actuellement le développement de l'énergie solaire. Parmi eux, l'élévation de la température des cellules induit une dégradation du productible d'environ 12% dans le cas général. En dépit de ce constat, la structure actuel des modules PV n'a pas variée depuis sa création dans les années 70. L'objectif de cette thèse est d'évaluer les facteurs d’impact qui gouverne l'élévation de la température du module PV en vue d’identifier les moyens de la réduire de manière significative. Un modèle multi-physique est construit pour prédire le comportement du module dans les conditions environnementales de production. Le modèle thermique est basé sur la radiation en milieu semi-transparent. Cette caractéristique conduit à déterminer les équations généralisées de Fresnel pour les milieux absorbants. Cela nous autorise à déterminer la caractéristique spectrale et angulaire de l’émissivité du verre. Le modèle de couplage optique-thermique-électrique est comparé aux mesures en conditions réelles et est capable de prédire le comportement du module sur une période de vingt-quatre heures. Le modèle est en mesure d’évaluer le gain obtenu en optimisant les composants du module. Une étude paramétrique identifie enfin les différentes améliorations permettant d’obtenir une réduction de la température de fonctionnement des modules PV. Cette thèse inclut un état de l'art (chapitre 1), une étude du transfert de chaleur radiative à l'échelle du module PV (chapitre 2), la description détaillée du modèle multiphysique (chapitre 3), l'étude du module PV au travers de la modélisation (chapitre 4), une étude paramétrique (chapitre 5) et une conclusion (chapitre 6). / In the context of greenhouse gas emissions and fossil and fissile resources depletion, solar energy is one of the most promising sources of power. The amount of renewable energies in the future energy mix depends on their availability, on their cost and on their level of efficiency. Various issues still limit the development of the solar energy. Among them, the temperature elevation into the module induces an efficiency degradation of 12% in standard cases. In spite of this statement, the actual solar module structure has not changed since its creation in the seventies, and the technologies are still evaluated at room temperature. The objective of this thesis is to study the impact factors which govern the module temperature elevation in order to identify ways to apply a significant reduction. A multi-physics modeling is built in order to predict the module behavior depending on the environmental conditions. The thermal modeling is grounded on the radiation into participating media. This feature leads to the determination of generalized Fresnel equation for absorbing media. It allows us to determine a spectral and hemispherical value of the glass emissivity. The optical-electrical-thermal modeling has been compared to measurement in real conditions and is able to predict the module behavior over a one-day period. It allows the evaluation of the gain obtained by optimizing the module components. A parametrical study identifies several improvements to lower the module operating temperature. The PhD work includes a state-of-the-art study (chapter 1), a study of the radiation heat transfer at PV module scale (chapter 2), the details of the multiphysics modeling (chapter 3), the study of the PV module through the modeling (chapter 4), a parametrical study (chapter 5) and a conclusion (chapter 6).

The development of the wind energy exploitation is a sum of processes which are subject to variety of heterogeneous factors. The nature and the leverage power of those factors vary and develop over time. Each regional or national location can be characterized by variety of factors, which are specific for respective locations. The wind energy development in the Czech Republic is influenced by number of barriers which restrain or slow down further progress. These barriers stem from environmental, economical, social and institutional disposition/nature of respective technologies. This thesis at first, based on available qualitative and quantitative data, describes and analyzes the situation and development of the wind energy exploitation. Specifics of the wind energy are placed in the context of selected European countries where factors and barriers influencing the development is described. The theme is regarded with spatio-temporal distribution of a "new technology". The thesis goes on focusing on identification of barriers that have impact on the wind energy development in the Czech Republic. Those restrictions/barriers are subsequently confronted with stands and perception of specific stakeholders, which are involved in the process. Analyses are carried out not only on individual barriers but also...

Support for electricity generation from renewable energy sources is one of measures aimed at switch of European economies from fossil fuels to renewables. In the past a lot of attention was paid to the theoretical assessment of different support schemes, however, analysis of the empirical data on those schemes is somewhat lacking. This thesis analyses assessment of two types of support schemes in three countries on empirical data. The main contribution of this work is (i) expansion of previously used methodology that analyses relationship between investments into electricity generation from renewable energy and the net present value of such investments, and (ii) inclusion of the Czech Republic into the list of observed countries. JEL Classification E61, O31, O33, O38, Q28, Q42 Keywords renewables, RES-E, photovoltaics Author's e-mail jbizek@gmail.com Supervisor's e-mail milan.scasny@czp.cuni.cz

La société TRAXENS propose une solution innovante permettant le suivi de l'état d'un conteneur (position, température, chocs, etc.). Ce service est basé sur un capteur sans fil appelé TRAXENS-BOX dont la durée de vie doit être étendue avec un volume de batterie limité. La présence d'une quantité d'énergie vibratoire non négligeable dans l'environnement du conteneur multimodal oriente donc vers la récupération d'énergie vibratoire. L'objectif principal de ce travail de thèse est donc d'identifier une solution permettant de récupérer l'énergie vibratoire dans le contexte particulier du conteneur caractérisé notamment par des vibrations verticales, aléatoires et très basses fréquences.On commence donc par introduire un modèle complet de récupérateur d'énergie vibratoire électromagnétique basé sur un oscillateur à un degré de liberté avant d'étudier son comportement lorsqu'il est soumis à des excitations harmoniques puis aléatoires ; on peut alors en déduire des règles de dimensionnement permettant la conception d'un récupérateur d'énergie vibratoire linéaire hautes performances. Le modèle est ensuite utilisé pour prouver l'intérêt de l'introduction d'une non-linéarité de Duffing dans la raideur du récupérateur, notamment sous les vibrations du transport routier. La partie théorique se termine alors par une comparaison mettant en opposition plusieurs configurations de récupérateur dans le cadre de l'application TRAXENS-BOX ; la solution retenue est l'utilisation d'une raideur non-linéaire HSLD (High Static Low Dynamic).On propose ensuite la conception optimisée puis la fabrication d'un démonstrateur linéaire hautes performances qui nous permet de valider les règles de dimensionnement énoncés dans la partie théorique. Enfin, le démonstrateur est modifié de manière à obtenir un comportement HSLD et prouver la faisabilité de ce concept. / TRAXENS company proposes an innovative solution to enable the monitoring of shipping containers (position, temperature, shocks, etc.). This service is based on a wireless sensor called TRAXENS-BOX whose lifetime must be extended by maintaining a small energy storage volume. In the environment of a shipping container, the presence a non-negligible amount of vibration makes energy harvesting a viable solution. The main objective of this work is to identify the means to scavenge vibration energy in the singular context of shipping container characterized by very low frequency, random and vertical vibration.First, a general electromagnetic vibration energy harvester model based on a single degree of freedom oscillator is introduced before analyzing its behavior when submitted to harmonic and random excitations ; rules to design high performances linear vibration energy harvester are then deduced. Henceforth, the model is used to prove the interest of introducing a Duffing nonlinearity in the harvester stiffness, especially under road induced vibration. The theoretical part ends with performance comparison between several harvester configurations within TRAXENS-BOX context ; the chosen solution is the use of a HSLD (High Static Low Dynamic) stiffness.Then, the design and fabrication of a linear high performances prototype is conducted to validate design rules drawn from the theoretical part. Finally, a HSLD stiffness is added to the prototype to prove the feasibility of this technique.

Thesis (doctoral)--Universität Hamburg, 2006. / Includes bibliographical references (p. 119-137). Also available via the internet.