Tesi sul tema "Energy"

La creixent demanda energètica, l’esgotament dels combustibles fòssils i l’augment de l’escalfament global a causa de l’emissió de carboni ha donat lloc a la necessitat d’un sistema energètic alternatiu, global i respectuós amb el medi ambient. L’energia solar es considera una de les formes d’energia més inesgotables d’aquest univers, però té el problema de la baixa eficiència a causa de les diferents condicions ambientals. El panell solar presenta un comportament no lineal en condicions climàtiques reals i la potència de sortida fluctua amb la variació de la irradiació solar i la temperatura. El canvi de les condicions meteorològiques i el comportament no lineal dels sistemes fotovoltaics suposen un repte en el seguiment de diferents PowerPoint màxims. Per tant, per extreure i lliurar contínuament la màxima potència possible del sistema fotovoltaic, en determinades condicions ambientals, s’ha de formular l’estratègia de control de seguiment del punt de potència màxima (MPPT) que funcioni contínuament el sistema fotovoltaic al seu MPP. Es necessita un controlador no lineal robust per garantir el MPPT mitjançant la manipulació de les línies no lineals d’un sistema i el fa robust contra les condicions ambientals canviants. El control de mode lliscant (SMC) s’utilitza àmpliament en sistemes de control no lineals i s’ha implementat en sistemes fotovoltaics (PVC) per rastrejar MPP. SMC és robust contra les pertorbacions, les incerteses del model i les variacions paramètriques. Representa fenòmens indesitjables com el xerramec, inherent al fet que provoca pèrdues d’energia i calor. En aquesta tesi, en primer lloc, es formula un controlador SMC d’ordre sencer per extreure la màxima potència d’un sistema solar fotovoltaic en condicions climàtiques variables que utilitzen l’esquema MPPT de pertorbació i observació (P \ & O) del sistema fotovoltaic autònom proposat. El sistema proposat consta de dos esquemes de bucles, a saber, el bucle de cerca i el bucle de seguiment. P&O MPPT s’utilitza al bucle de cerca per generar el senyal de referència i un controlador SMC de seguiment s’utilitza a l’altre bucle per extreure la màxima potència fotovoltaica. El sistema fotovoltaic es connecta amb la càrrega mitjançant el convertidor d’alimentació electrònic DC-DC de potència. Primer es deriva un model matemàtic del convertidor d’augment i, basat en el model derivat, es formula un SMC per controlar els impulsos de la porta del commutador del convertidor d’augment. L’estabilitat del sistema de bucle tancat es verifica mitjançant el teorema d’estabilitat de Lyapunov. L’esquema de control proposat es prova amb diferents nivells d’irradiació i els resultats de la simulació es comparen amb el controlador de derivades integrals proporcionals clàssiques (PID). El SMC clàssic representa fenòmens indesitjables com el xerramec, inherent al fet que provoca pèrdues d’energia i calor. A la següent part d’aquesta tesi, es discuteix el disseny del controlador de mode lliscant adaptatiu (ASMC) per al sistema fotovoltaic proposat. El control adoptat s’executa mitjançant un ASMC i la millora s’actualitza mitjançant un algorisme d’optimització MPPT de mètode de cerca de patrons millorats (IPSM). S’utilitza un MPPT IPSM per generar la tensió de referència per tal de comandar el controlador ASMC subjacent. S’ha dut a terme una comparació amb altres dos algoritmes d’optimització, a saber, Perturb \ & Observe (P&O) i Particle Swarm Optimization (PSO) amb IPSM per MPPT. Com a estratègia no lineal, l’estabilitat del controlador adaptatiu es garanteix mitjançant la realització d’una anàlisi de Lyapunov. El rendiment de les arquitectures de control proposades es valida comparant les propostes amb la del conegut i àmpliament utilitzat controlador PID.
La creciente demanda de energía, el agotamiento de los combustibles fósiles y el aumento del calentamiento global debido a la emisión de carbono han hecho surgir la necesidad de un sistema energético alternativo, de eficiencia general y respetuoso con el medio ambiente. La energía solar se considera una de las formas de energía más inagotables de este universo, pero tiene el problema de la baja eficiencia debido a las diferentes condiciones ambientales. El panel solar exhibe un comportamiento no lineal en condiciones climáticas reales y la potencia de salida fluctúa con la variación de la irradiancia solar y la temperatura. Las condiciones climáticas cambiantes y el comportamiento no lineal de los sistemas fotovoltaicos plantean un desafío en el seguimiento de la variación máxima de PowerPoint. Por lo tanto, para extraer y entregar continuamente la máxima potencia posible del sistema fotovoltaico, en determinadas condiciones ambientales, se debe formular la estrategia de control de seguimiento del punto de máxima potencia (MPPT) que opere continuamente el sistema fotovoltaico en su MPP. Se requiere un controlador no lineal robusto para asegurar MPPT manejando las no linealidades de un sistema y haciéndolo robusto frente a condiciones ambientales cambiantes. El control de modo deslizante (SMC) se usa ampliamente en sistemas de control no lineales y se ha implementado en sistemas fotovoltaicos (PVC) para rastrear MPP. SMC es robusto contra perturbaciones, incertidumbres del modelo y variaciones paramétricas. Representa fenómenos indeseables como el parloteo, inherentes a él, que provocan pérdidas de energía y calor. En esta tesis, en primer lugar, se formula un controlador SMC de orden entero para extraer la máxima potencia de un sistema fotovoltaico solar en condiciones climáticas variables empleando el esquema MPPT de perturbar y observar (P&O) para el sistema fotovoltaico autónomo propuesto. El sistema propuesto consta de dos esquemas de bucles, a saber, el bucle de búsqueda y el bucle de seguimiento. P&O MPPT se utiliza en el bucle de búsqueda para generar la señal de referencia y se utiliza un controlador SMC de seguimiento en el otro bucle para extraer la máxima potencia fotovoltaica. El sistema fotovoltaico está conectado con la carga a través del convertidor elevador DC-DC electrónico de potencia. Primero se deriva un modelo matemático del convertidor elevador y, en base al modelo derivado, se formula un SMC para controlar los pulsos de puerta del interruptor del convertidor elevador. La estabilidad del sistema de circuito cerrado se verifica mediante el teorema de estabilidad de Lyapunov. El esquema de control propuesto se prueba bajo diferentes niveles de irradiancia y los resultados de la simulación se comparan con el controlador clásico proporcional integral derivado (PID). El SMC clásico describe fenómenos indeseables como el parloteo, inherente a él, que causa pérdidas de energía y calor. En la siguiente parte de esta tesis, se analiza el diseño del controlador de modo deslizante adaptativo (ASMC) para el sistema fotovoltaico propuesto. El control adoptado se ejecuta utilizando un ASMC y la mejora se actualiza utilizando un algoritmo de optimización MPPT del Método de búsqueda de patrón mejorado (IPSM). Se utiliza un IPSM MPPT para generar el voltaje de referencia para controlar el controlador ASMC subyacente. Se ha realizado una comparación con otros dos algoritmos de optimización, a saber, Perturb \ Observe (P&O) y Particle Swarm Optimization (PSO) con IPSM para MPPT. Como estrategia no lineal, la estabilidad del controlador adaptativo está garantizada mediante la realización de un análisis de Lyapunov.
The increasing energy demands, depleting fossil fuels, and increasing global warming due to carbon emission has arisen the need for an alternate, overall efficiency, and environment-friendly energy system. Solar energy is considered to be one of the most inexhaustible forms of energy in this universe, but it has the problem of low efficiency due to varying environmental conditions. Solar panel exhibits nonlinear behavior under real climatic conditions and output power fluctuates with the variation in solar irradiance and temperature. Changing weather conditions and nonlinear behavior of PV systems pose a challenge in the tracking of varying maximum PowerPoint. Hence, to continuously extract and deliver the maximum possible power from the PV system, under given environmental conditions, the maximum power point tracking (MPPT) control strategy needs to be formulated that continuously operates the PV system at its MPP. A robust nonlinear controller is required to ensure MPPT by handling nonlinearities of a system and making it robust against changing environmental conditions. Sliding mode control (SMC) is extensively used in non-linear control systems and has been implemented in photovoltaic systems (PV) to track MPP. SMC is robust against disturbances, model uncertainties, and parametric variations. It depicts undesirable phenomena like chattering, inherent in it causing power and heat losses. In this thesis, first, an integer order SMC controller is formulated for extracting maximum power from a solar PV system under variable climatic conditions employing the perturb and observe (P&O) MPPT scheme for the proposed stand-alone PV system. The proposed system consists of two loops schemes, namely the searching loop and the tracking loop. P&O MPPT is utilized in the searching loop to generate the reference signal and a tracking SMC controller is utilized in the other loop to extract the maximum PV power. PV system is connected with load through the power electronic DC-DC boost converter. A mathematical model of the boost converter is derived first, and based on the derived model, an SMC is formulated to control the gate pulses of the boost converter switch. The closed-loop system stability is verified through the Lyapunov stability theorem. The proposed control scheme is tested under varying irradiance levels and the simulation results are compared with the classical proportional integral derivative (PID) controller. Classical SMC depicts undesirable phenomena like chattering, inherent in it causing power and heat losses. In the next part of this thesis, the design of the adaptive sliding mode controller (ASMC) is discussed for the proposed PV system. The adopted control is executed utilizing an ASMC and the enhancement is actualized utilizing an Improved Pattern Search Method (IPSM) MPPT optimization algorithm. An IPSM MPPT is used to generate the reference voltage in order to command the underlying ASMC controller. Comparison with two other optimization algorithms, namely, a Perturb & Observe (P&O) and Particle Swarm Optimization (PSO) with IPSM for MPPT has been conducted. As a non-linear strategy, the stability of the adaptive controller is guaranteed by conducting a Lyapunov analysis. The performance of the proposed control architectures is validated by comparing the proposals with that of the well-known and widely used PID controller. The simulation results validate that the proposed controller effectively improves the voltage tracking, system power with reduced chattering effect, and steady-state error. A tabular comparison is provided at the end of each optimization algorithm category as a resume quantitative comparison. It is anticipated that this work will serve as a reference and provides important insight into MPPT control of the PV systems.

TESIS PARA OPTAR AL GRADO DE MAGÍSTER EN ADMINISTRACIÓN
Pizarro, Ramón, [Parte I], Mella, Guillermo, [Parte II]
A partir de la publicación de la Ley 20.805 del Ministerio de Energía, clientes de energía eléctrica podrán optar por un régimen de tarifa libre, en detrimento de una tarifa regulada, por las empresas distribuidoras de energía del mercado local. El cambio supuso la creación de una oportunidad de negocio e involucró al sector energético, a los encargados de la generación (Generadoras), a los encargados de la transmisión y encargados de la distribución (Empresas Eléctricas). El proyecto de "Brokers de Energía en Chile”, asume como desafío el asesoramiento estratégico y técnico, para usuarios susceptibles de cambiarse de tarifas reguladas a tarifas libres de mercado, dado que para muchas empresas las materias energéticas, no son el core de sus negocios. El servicio será suministrado por la sociedad Energy Advisory Ltda., con marca comercial “Energi-A”, que prestará servicios de asesorías de eficiencia energética a compañías comerciales, industriales, empresas de servicios y explotación de materias primas, ubicadas en la I, II y Región Metropolitana del país. El objetivo de Energi-A, es alcanzar en el plazo de 3 años, ingresos por sobre los MM$222, que es el proyectado de ingresos de contratos solo con 7 nuevos clientes que tenga la capacidad conectada mínima que indica la ley. El ingreso corresponde al cobro de la comisión del servicio de asesoría, a un promedio del 12% con una proyección a 12 meses, sobre los ahorros de eficiencia en materia energética del cliente. Con una inversión para capital de trabajo de MM$28, principalmente destinado a soportar la operación los primeros años del proyecto. Por la naturaleza del servicio de asesorías en eficiencia energética, el proyecto no presenta riesgos críticos en la propuesta del plan estratégico. Por lo tanto, la invitación es a sumarse a un proyecto que promueve “La eficiencia energética”, que reviste una importancia crítica para alcanzar mejores usos de recursos y aporta un gramo de arena a combate por el cambio climático.

This doctoral study discusses how to control fluctuating renewable energy sources at converter, unit, and system layers to deliver smoothed power output to the grid. This is particularly relevant to renewable power generation since the output power of many kinds of renewable energy sources have huge fluctuations (e.g. solar, wind and wave) that needs to be properly treated for grid integration. In this research, the energy quality is developed to describe the friendliness and compatibility of power flows/waveforms to the grid, by contrast with the well-known concept of power quality which is used to assess the voltage and current waveforms. In Chapter 1 & 2, a background introduction and a literature review of studied subjects are presented, respectively. In Chapter 3, the problem of determining the PI parameters in dq decoupling control of voltage source converter (VSC) is studied based on a state-space model. The problems of the conventional method when there is insufficient interface resistance are addressed. New methods are proposed to overcome these drawbacks. In Chapter 4 & 5, energy quality and the energy filters (EFs) are proposed as tools to assess and manage power fluctuations of renewable energy sources. The proposed EFs are energy storage control systems that could be implemented on a variety of energy storage hardware. EFs behave like low-pass filters to the power flows. Finally, in Chapter 6, as an application example of renewable power plant with energy filter control and smoothed power output, a master-slave wave farm system is proposed. The wave farm system uses enlarged rotor inertia of electric machines as self-energy storage devices.

There has been used four times more energy in the world compared to 1950 year. The main share falls primarily on households and the growing industry. The economic downturn in Ukraine and the countries of former USSR does not influence the consumption of energy – it remains high.

Instrumentation: Flute -- Clarinet in Bb -- Bass Clarinet in Bb -- Alto Saxophone in Eb -- Baritone Saxophone in Eb -- Bassoon -- Horns I and II in F -- Trumpet in Bb -- Bass Trombone -- Percussion I (Suspended Cymbal, Woodblocks, Timpani: 32-30”, 29-28”, 26-25”, and 23”) -- Percussion II (Tom-Toms, Suspended Cymbal) -- Keyboard Percussion (Marimba, Vibraphone) -- Violin I -- Violin II -- Viola -- Violoncello Double Bass All wind instruments should be one to a part, unless the conductor thinks doubling is necessary for balance. The string doublings should be as follows: 3 players to a part for Violin I, Violin II, Viola, and Violoncello; and 2 players for the Double Bass part.
Thesis (M.Mus.)--Wichita State University, College of Fine Arts, Dept. of Music
The score is in C. Energy is a four movement, continuous piece. The movements are: I. Upward -- II. Forward -- III. Circular -- IV. Namaste. Each movement intends to convey the different energies created in certain yoga positions.

The goal of the master's thesis is elaborating energy audit within the current legislation in Czech republic. Thesis includes introduction, in which has been described photovolatics panels. The building is evaluated in terms of energetic, economic and environmental. Part of the energy audit was to designed and evaluated austerity measures.

This master thesis introduces a new technology applicable to nearly all mobile and portable electrical devices since all of them need energy to operate. This thesis attempts to cut the last wire - this one the wire to the primary power source. In other words, fast and efficient wireless energy transference through a strong, focused near magnetic field whose fast attenuation will avoid interference with surrounding communication systems or human harm. This energy is transferred to and will be stored inside the mobile device where nothing but a small and simple secondary circuit has been placed. The thesis project began by creating an initial SPICE computer model, providing an easy and rapid way of testing both convergence and feasibility of the topology as the design evolved from the well-known and widely used Switch Model Power Supply technology through to the detailed design and implementation of the prototype, including supporting the iterative process of testing and optimizing, all stages are carefully described in the document. The thesis shows both theoretically and practically that this idea is feasible and capable of power transmission.
Detta examensarbete introducerar en ny teknologi som är applicerbar till de flesta mobila och portabla elektriska apparater då dessa behöver energi för att fungera. Detta arbete försöker klippa den sista ledningen den som leder till den primära kraftkällan. Med andra ord, är denna teknik en snabb och effektiv trådlös energiöverföring genom ett starkt, fokuserat närbeläget magnetfält. Tack vare magnetfältets kraftiga dämpning undviks interferens med intilliggande kommunikationssystem eller personskador. Denna energi är överförd till, och lagras inuti en bärbar apparat där endast en liten och enkel sekundärkrets har placerats. Examensarbetsprojektet påbörjades med skapandet av en inledande SPICE datormodell. Modellen möjliggjorde ett enkelt och snabbt sätt att testa både konvergens och genomförbarhet av topologin samtidigt som designen utvecklades från den välkända och vitt använda Switch Power Supply-teknologin till den detaljerade designen och implementationen av prototypen. Modellen stöttade samtidigt den iterativa processen av test och optimering. Alla faser är utförligt beskrivna i rapporten och arbetet visar både teoretiskt och praktiskt att denna idé är genomförbar och möjliggör kraftöverföring.

This thesis aims to determine energy compensation following exercise induced energy expenditure (ExEE). The specific objectives were: I) to determine the impact of the time spent performing physical activity (PA) of varying intensities on body weight and composition (Study 1); II) to determine the overall energy compensation and the major predictors of energy compensation through the systematic review approach (Study 2); III) to develop new methods to measure energy intake (EI) (Study 3) and time spent performing different activities (Study 4); IV) to determine the effects of a lower (LI) and higher intensity (HI) ExEE intervention on energy compensation (Study 5); and V) to investigate the inter-individual variability regarding exercise induced energy compensation (Study 6). In Study 1, women spending more time performing light-intensity PA were shown to have lower adiposity compared to women spending more time performing moderate- and high-intensity PA. Results from Study 2 (systematic review) show an overall energy compensation of 25% following exercise interventions and that fat mass (FM), exercise intensity and duration of the intervention are the main predictors of energy compensation. To better capture energy compensation (i.e., EI and EE), new methods to measure EI and time spent performing activities were developed (Studies 3 and 4) and used in the following studies. In Study 5, overweight/obese women training at HI displayed higher energy compensation when compared to women training at LI, which was accompanied by a reduction of NSPA (non-structured physical activity) and a greater amount of time spent lying down. Results from Study 6 showed that complete compensators (CC) had higher EI, fat and carbohydrate intake at the onset of the ExEE intervention when compared to incomplete compensators (IC). However, the results also showed that dietary disinhibition was increased, whereas NSPA was decreased at the end of the intervention in IC. Taken together, these studies emphasize that weight loss following exercise is impeded by energy compensation. In addition to the impact of FM, exercise intensity and duration of the intervention on energy compensation, NSPA and cognitive factors also seem to modify energy compensation that occurs as a result of exercise.

The main objective of this thesis is to provide an empirical assessment of the popular methodologies for modelling the underlying spot price dynamics in energy markets. After a brief introduction in the alternative forms of derivation that may be used for speculative and risk management purposes in energy markets, we assess the performance of the standard Black's framework in modelling energy prices. For the first time in the literature we use a powerful and realistic data set which covers oil, gas and electricity markets and tests the appropriateness of the Geometric Brownian Motion process to explain the observed dynamics of the spot prices in these markets. We also provide spreadsheet based computer algorithms to price popular energy derivatives based on the Geometric Brownian Motion specifications. In Chapter-3 we try to accommodate observed stylised facts in the spot price behaviour, namely mean reversion and jumps. For the first time in the literature we test a jump diffusion model, and a mean reversion jump diffusion model against our broad data set and compare the findings to the Black's Geometric Brownian Motion specifications. In Chapter-4 we use a forward curve approach as an alternative-modelling framework to the spot price models. Based upon an almost proprietary data set of historical forward curves, we determine the number of independent factors that are needed to model the forward curve's dynamic evolution. After carrying out principal component analysis on historical forward data a threefactor-model emerges as the most appropriate for energy markets in general. The first factor being the volatility (level effect), the second the smile and the third sesonality. Finally in Chapter-5 of the thesis we compare the ability of spot models (Jump Diffusion and Mean Reversion Jump Diffusion Model) and forward curve based models to price WTI options. The results show that the Jump Diffusion Model is the best model as the option prices given are very accurate in comparison with the other models and closest to the market observed options prices.

With respect to the continuous growth of computing systems, the energy-efficiency requirement of their processes becomes even more important. Different configurations, implying different energy-efficiency of the system, could be used to perform the process. A configuration denotes the choice among different hard- and software settings (e.g., CPU frequency, number of threads, the concrete algorithm, etc.). The identification of the most energy-efficient configuration demands to benchmark all configurations. However, this benchmarking is time- and energy-consuming, too. This thesis explores (a) the effect of dynamic voltage and frequency scaling (DVFS) in combination with dynamic concurrency throttling (DCT) on the energy consumption of (de)compression, DBMS query executions, encryption/decryption and sorting; and (b) a generic approach to reduce the benchmarking efforts to determine the optimal configuration. Our findings show that the utilization of optimal configurations can save wavg. 15.14% of energy compared to the default configuration. Moreover, we propose a generic heuristic (fractional factorial design) that utilizes data mining (adaptive instance selection) together with machine learning techniques (multiple linear regression) to decrease benchmarking effort by building a regression model based on the smallest feasible subset of the benchmarked configurations. Our approach reduces the energy consumption required for benchmarking by 63.9% whilst impairing the energy-efficiency of performing the computational process by only 1.88 pp, due to not using the optimal but a near-optimal configuration.

Our relationship with the environment is bilateral. If we want to live in clear world that takes care about us we must take care about the environment. It is evident that healthy population and high quality of life is possible only in healthy environment.

Ultra low power wireless sensors and sensor systems are of increasing interest in a variety of applications ranging from structural health monitoring to industrial process control. Electrochemical batteries have thus far remained the primary energy sources for such systems despite the finite associated lifetimes imposed due to limitations associated with energy density. However, certain applications (such as implantable biomedical electronic devices and tire pressure sensors) require the operation of sensors and sensor systems over significant periods of time, where battery usage may be impractical and add cost due to the requirement for periodic re-charging and/or replacement. In order to address this challenge and extend the operational lifetime of wireless sensors, there has been an emerging research interest on harvesting ambient vibration energy. Vibration energy harvesting is a technology that generates electrical energy from ambient kinetic energy. Despite numerous research publications in this field over the past decade, low power density and variable ambient conditions remain as the key limitations of vibration energy harvesting. In terms of the piezoelectric transducers, the open-circuit voltage is usually low, which limits its power while extracted by a full-bridge rectifier. In terms of the interface circuits, most reported circuits are limited by the power efficiency, suitability to real-world vibration conditions and system volume due to large off-chip components required. The research reported in this thesis is focused on increasing power output of piezoelectric transducers and power extraction efficiency of interface circuits. There are five main chapters describing two new design topologies of piezoelectric transducers and three novel active interface circuits implemented with CMOS technology. In order to improve the power output of a piezoelectric transducer, a series connection configuration scheme is proposed, which splits the electrode of a harvester into multiple equal regions connected in series to inherently increase the open-circuit voltage generated by the harvester. This topology passively increases the rectified power while using a full-bridge rectifier. While most of piezoelectric transducers are designed with piezoelectric layers fully covered by electrodes, this thesis proposes a new electrode design topology, which maximizes the raw AC output power of a piezoelectric harvester by finding an optimal electrode coverage. In order to extract power from a piezoelectric harvester, three active interface circuits are proposed in this thesis. The first one improves the conventional SSHI (synchronized switch harvesting on inductor) by employing a startup circuitry to enable the system to start operating under much lower vibration excitation levels. The second one dynamically configures the connection of the two regions of a piezoelectric transducer to increase the operational range and output power under a variety of excitation levels. The third one is a novel SSH architecture which employs capacitors instead of inductors to perform synchronous voltage flip. This new architecture is named as SSHC (synchronized switch harvesting on capacitors) to distinguish from SSHI rectifiers and indicate its inductorless architecture.

Die Einführung neuartiger Energietechnologien wird allgemein als der Schlüssel zur Senkung klimaschädlicher Treibhausgase angesehen. Allerdings ist die Abbildung derartiger Technologien in numerischen Modellen zur Simulation und ökonomischen Analyse von energie- und klimaschutzpolitischen Maßnahmen vielfach noch rudimentär. Die Dissertation entwickelt neue Ansätze zur Einbindung von technologischen Innovationen in energie-ökonomische allgemeine Gleichgewichtsmodelle, mit dem Ziel den Energiesektor realitätsnäher abzubilden. Die Dissertation adressiert einige der Hauptkritikpunkte an allgemeinen Gleichgewichtsmodellen zur Analyse von Energie- und Klimapolitik: Die fehlende sektorale und technologische Disaggregation, die beschränkte Darstellung von technologischem Fortschritt, und das Fehlen von einem weiten Spektrum an Treibhausgasminderungsoptionen. Die Dissertation widmet sich zwei Hauptfragen: (1) Wie können technologische Innovationen in allgemeine Gleichgewichtsmodelle eingebettet werden? (2) Welche zusätzlichen und politikrelevanten Informationen lassen sich durch diese methodischen Erweiterungen gewinnen? Die Verwendung eines sogenannten Hybrid-Ansatzes, in dem neuartige Technologien für Stromerzeugung und Eisen- und Stahlherstellung in ein dynamisch multi-sektorales CGE Modell eingebettet werden, zeigt, dass technologiespezifische Effekte von großer Bedeutung sind für die ökonomische Analyse von Klimaschutzmaßnahmen, insbesondere die Effekte hinsichtlich von Technologiewechsel und dadurch bedingten Änderungen der Input- und Emissionsstrukturen. Darüber hinaus zeigt die Dissertation, dass Lerneffekte auf verschiedenen Stufen der Produktionskette abgebildet werden müssen: Für regenerative Energien, zum Beispiel, nicht nur bei der Anwendung von Stromerzeugungsanlagen, sondern ebenso auf der vorgelagerten Produktionsstufe bei der Herstellung dieser Anlagen. Die differenzierte Abbildung von Lerneffekten in Exportsektoren, wie zum Beispiel Windanlagen, verändert die Wirtschaftlichkeit und die Wettbewerbsfähigkeit und hat wichtige Implikationen für die ökonomische Analyse von Klimapolitik.
Energy technologies and innovation are considered to play a crucial role in climate change mitigation. Yet, the representation of technologies in energy-economy models, which are used extensively to analyze the economic, energy and environmental impacts of alternative energy and climate policies, is rather limited. This dissertation presents advanced techniques of including technological innovations in energy-economy computable general equilibrium (CGE) models. New methods are explored and applied for improving the realism of energy production and consumption in such top-down models. The dissertation addresses some of the main criticism of general equilibrium models in the field of energy and climate policy analysis: The lack of detailed sectoral and technical disaggregation, the restricted view on innovation and technological change, and the lack of extended greenhouse gas mitigation options. The dissertation reflects on the questions of (1) how to introduce innovation and technological change in a computable general equilibrium model as well as (2) what additional and policy relevant information is gained from using these methodologies. Employing a new hybrid approach of incorporating technology-specific information for electricity generation and iron and steel production in a dynamic multi-sector computable equilibrium model it can be concluded that technology-specific effects are crucial for the economic assessment of climate policy, in particular the effects relating to process shifts and fuel input structure. Additionally, the dissertation shows that learning-by-doing in renewable energy takes place in the renewable electricity sector but is equally important in upstream sectors that produce technologies, i.e. machinery and equipment, for renewable electricity generation. The differentiation of learning effects in export sectors, such as renewable energy technologies, matters for the economic assessment of climate policies because of effects on international competitiveness and economic output.

This paper presents the energy saving curtains, in order to make the

consumers be more aware of the energy efficiency of the energy saving

curtains, the paper gave related analysis and conclusions.

The work was performed by using the Parasol Program, developed by Lunds University, Sweden. The Program is used for quantifying the influence of window size, glass type, textile type, wall thermal insulation and sun shading on annual energy use and indoor thermal comfort. The results which are obtained from the calculations are applicable to similar climatic and environment conditions. Calculations were performed to investigate the potential for using sunshade devices to reduce annual energy demand for cooling and heating. Different materials and dimensions of the energy saving

curtain are used as variables in the analysis. The results indicated that for the current climatic conditions and other related factors, the total reduction rate of the annual energy consumption of office used buildings in Stockholm is estimated generally 20% -30% lower comparing to those buildings without energy saving curtain system. That means at least 20% of energy cost can be saved by the energy saving curtain system.

This thesis consists of four self-contained papers related to energydemand and household cooking energy.Paper [I] examine the impact of price, income and non-economicfactors on gasoline demand using a structural time series model. Theresults indicated that non-economic factors did have an impact ongasoline demand and also one of the largest contributors to changes ingasoline demand in both countries, especially after the 1990s. Theresults from the time varying parameter model (TVP) indicated thatboth price and income elasticities were varying over time, but thevariations were insignificant for both Sweden and the UK. Theestimated gasoline trend also showed a similar pattern for the twocountries, increasing continuously up to 1990 and taking a downturnthereafter.Paper [II] studies whether the commonly used linear parametricmodel for estimating aggregate energy demand is the correctfunctional specification for the data generating process. Parametricand nonparametric econometric approaches to analyzing aggregateenergy demand data for 17 OECD countries are used. The resultsfrom the nonparametric correct model specification test for theparametric model rejects the linear, log-linear and translogspecifications. The nonparametric results indicate that the effect of theincome variable is nonlinear, while that of the price variable is linearbut not constant. The nonparametric estimates for the price variable isrelatively low, approximately −0.2.Paper [III] relaxed the weak separability assumption betweengasoline demand and labor supply by examining the effect of laborsupply, measured by male and female working hours on gasolinedemand. I used a flexible semiparametric model that allowed fordifferences in response to income, age and labor supply, respectively.Using Swedish household survey data, the results indicated that therelationship between gasoline demand and income, age and laborsupply were non-linear. The formal separability test rejects the null ofseparability between gasoline demand and labor supply. Furthermore,there was evidence indicating small bias in the estimates when oneignored labor supply in the model.Paper [IV] investigated the key factors influencing the choice ofcooking fuels in Ghana. Results from the study indicated thateducation, income, urban location and access to infrastructure werethe key factors influencing household’s choice of the main cookingfuels (fuelwood, charcoal and liquefied petroleum gas). The study alsofound that, in addition to household demographics and urbanization,the supply (availability) of the fuels influenced household choice forthe various fuels. Increase in household income was likely to increasethe probability of choosing modern fuel (liquefied petroleum gas andelectricity) relative to solid (crop residue and fuelwood) and transitionfuel (kerosene and charcoal).

This thesis presents an optimal method of designing and controlling an oscillating energy harvesting system. Many new and emerging energy harvesting systems, such as the energy harvesting backpack and ocean wave energy harvesting, capture energy normally expelled through mechanical interactions. Often the nature of the system indicates slow system time constants and unsteady AC voltages. This paper reveals a method for achieving maximum energy harvesting from such sources with fast determination of the optimal operating condition. An energy harvesting backpack, which captures energy from the interaction between the user and the spring decoupled load, is presented in this paper. The new control strategy, maximum energy harvesting control (MEHC), is developed and applied to the energy harvesting backpack system to evaluate the improvement of the MEHC over the basic maximum power point tracking algorithm.
M.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE

Thesis advisor: Donnah Canavan
Abstract Energy is an emerging concept in social psychology. Baumeister et. al., likening energy to a muscle, have defined exertion of self control as an energy depleting behavior. Energy depletion is measured by reduced performance on a subsequent self-control task. In contrast, Canavan's work on social energy focuses on energy generation and replenishment. Social energy is produced when two or more people are intrinsically interested in the same thing and form a satisfying relationship over this interest. Individuals high in social energy exert more effort, persist longer, and perform better. The present study was conducted in a 2x2 ANOVA design with Social Energy and Depletion as the independent variables and persistence and performance as the dependent variables. Participants worked in groups of two or three groups and were randomly assigned to conditions. In High Social Energy, they imagined managing The Beatles. In the No Social Energy, they imagined managing a cover band playing Beatle's songs. The participants then performed either a depleting or non-depleting proofreading task. Afterwards, the dependent variables were assessed in several tasks: a handgrip task and a measure of creativity and persistence. The results indicate: (1) no significant effect of depletion on the handgrip task and (2) no significant effect of social energy on any of the behavioral measures (i.e. handgrip task or creativity measure). In conclusion, the results did not support either the Depletion or Social Energy behavioral predictions. In the questionnaire data differences between Social Energy and No Social Energy showed significantly higher energy states, social energy, intrinsic motivation, flow, and most important more effort and hard work. The study does improve upon former Social Energy studies in terms of its conceptualization because it successfully manipulated No Social Energy and presented a more sophisticated conceptualization of energy. The manipulations of Social Energy and Depletion interfered with each other making it impossible to test the hypotheses. Paper to be presented at the annual Psychology Honors Conference, Psychology Department, Boston College, Chestnut Hill, Massachusetts, May 2005
Thesis (BS) — Boston College, 2005
Submitted to: Boston College. College of Arts and Sciences
Discipline: Psychology
Discipline: College Honors Program

Ubiquitous computing and pervasive networks are prevailing to impact almost every part of our daily lives. Convergence of technologies has allowed electronic devices to become untethered. Cutting of the power-cord and communications link has provided many benefits, mobility and convenience being the most advantageous, however, an important but lagging technology in this vision is the power source. The trend in power density of batteries has not tracked the advancements in electronic systems development. This has provided opportunity for a bridging technology which uses a more integrated approach with the power source to emerge, where a device has an onboard self sustaining energy supply. This approach promises to close the gap between the increased miniaturisation of electronics systems and the physically constrained battery technology by tapping into the ambient energy available in the surrounding location of an application. Energy harvesting allows some of the costly maintenance and environmentally damaging issues of battery powered systems to be reduced. This work considers the characteristics and energy requirements of wireless sensor and actuator networks. It outlines a range of sources from which the energy can be extracted and then considers the conversion methods which could be employed in such schemes. This research looks at the methods and techniques for harvesting/scavenging energy from ambient sources, in particular from the motion of human traffic on raised flooring and stairwells for the purpose of powering wireless sensor and actuator networks. Mechanisms for the conversion of mechanical energy to electrical energy are evaluated for their benefits in footfall harvesting, from which, two conversion mechanisms are chosen for prototyping. The thesis presents two stair-mounted generator designs. Conversion that extends the intermittent pulses of energy in footfall is shown to be the beneficial. A flyback generator is designed which converts the linear motion of footfall to rotational torque is presented. Secondly, a cantilever design which converts the linear motion to vibration is shown. Both designs are mathematically modelled and the behaviour validated with experimental results & analysis. Power, energy and efficiency characteristics for both mechanisms are compared. Cost of manufacture and reliability are also discussed.

Master of Science
Department of Mechanical Engineering
Donald Fenton
The need to store and access electronic information is growing on a daily basis as more and more people conduct business and personal affairs through email and the internet. To meet these demands, high energy density data centers have sprung up across the United States and around world. To ensure that vital data centers run constantly, proper cooling must be maintained to prevent overheating and possible server damage from occurring. Emergency cooling systems for such systems typically utilize traditional batteries, backup generator, or a combination thereof. The electrical backup provides enough power to support cooling for essential components within the data centers. While this method has shown to be reliable and effective, there are several other methods that provide reliable emergency cooling at a fraction of the cost. This paper address the lack of information regarding the initial, operation, and maintenance costs of using Thermal Energy Storage (TES) tanks for emergency cooling. From research and various field examples, five emergency cooling system layouts were designed for various peak cooling loads. Looking at the different cooling loads, components, and system operations an economic evaluation of the system over a 20 year period was conducted. The economic analysis included the initial and maintenance costs of each system. In an effort to better understand power consumption of such systems and to help designer’s better estimate the long term costs of TES tanks systems, five layouts were simulated through a program called TRNSYS developed for thermal systems. To compare against current systems in place, a benefit to cost ratio was done to analyze TES versus a comparable UPS. The five simulated systems were one parallel pressurized tank, one parallel and one series atmospheric tank, one parallel low temperature chilled water, and one series ice storage tank. From the analysis, the ice storage and pressurized systems were the most cost effective for 1 MW peak cooling loads. For 5 MW peak cooling loads the ice storage and chilled water systems were the most cost effective. For 15 MW peak loads the chilled water atmospheric TES tanks were the most cost effective. From the simulations we concluded that the pressurized and atmospheric systems consumed the least amount of power over a 24 hour period during a discharge and recharge cycle of the TES tank. From the TRNSYS simulations, the ice storage system consumed 22 – 25% more energy than a comparable chilled water system, while the low temperature storage system consumed 6 – 8% more energy than the chilled water system. From the benefit-cost-ratio analysis, it was observed that all systems were more cost effective than a traditional battery UPS system of comparable size. For the smaller systems at 1 MW the benefit-cost-ratio ranged between 0.25 to 0.55, while for larger systems (15 MW) the ratio was between 1.0 to 3.5 making TES tanks a feasible option for providing emergency cooling for large and small systems.

This thesis investigated the use cases of Electric Vehicles (EV) and stationary battery storage in a multi-level energy system with high penetration of renewable DER. The different energy system levels considered include large and local level, distribution network and customer premises. The reduction of excess electricity due to high shares of renewable energy technologies by using EV with Vehicle to Grid capability in a future GB energy system was investigated. It was found that with EV in vehicle to grid mode integrated into the energy system, the utilisation of fluctuating wind power was increased. This was realised by minimising the curtailment of excess electricity and CO2 emissions. Also in a local energy system with a high share of intermittent renewable energy, EV with Vehicle to Grid capability can reduce electricity import of about 34%. A microgrid was modelled for evaluating the impact of electrical vehicle charging on voltage profiles and energy losses in a local distribution network with a high share of distributed energy resources. The results show that with a smart charging scheme, the voltage profiles remain within distribution network operator’s defined limit. A reduction of energy losses in the microgrid was also noted. An optimisation tool using an optimisation technique was developed for optimising charging and discharging of a stationary battery storage. This was simulated to evaluate the revenue streams for an existing photovoltaic generation system. The key benefit of the photovoltaic generation system to the owner is the ability to maximise feed in tariff revenue streams by maximising self-consumption using a wholesale electricity tariff. The impact of storage unit cost on the adoption of battery storage for the photovoltaic generation system was also simulated using a time of use tariff. It was found that battery storage for the simulated system will only be economically viable when battery unit cost drops to £138/kWh. The impact of an optimised distributed energy system simulated in the Lawrence Berkeley’s Distributed Energy Resources Customer Adoption Model (DER-CAM) on distribution network constraints was investigated using a soft-linking power flow simulation procedure. It was found that voltage excursions occur mostly during peak day-types. It was found out that not all optimised distributed energy systems are feasible from the distribution network’s point of view.

A fourth industrial revolution (Industry 4.0) is on the horizon. It is enabled by advancements in information and communication technologies (i.e. digitalization) and concepts such as the Internet of Things and cyber-physical systems. Industry 4.0 is expected to have great impact on the manufacturing and process industries, changing how products are developed, produced and sold. However, Industry 4.0 is a novel concept and its impacts are still uncertain. An increasingly strict climate and energy agenda in Sweden is putting pressure on the industrial sector and it is, therefore, important that the sector exploits the full potential Industry 4.0 can provide for increased sustainability. This thesis examines the status of digitalization in the Swedish energy intensive industries (i.e. pulp and paper, steel, and chemical industries) and how it could impact energy efficiency in the sector. Qualitative research methods were used to carry out the study. A literature review and in-depth interviews with employees within the industries were conducted. The results show that, while digitalization is considered important for the future competitiveness of the Swedish energy intensive industries, the digital maturity of the sector is not considered high. Digital technologies can increase energy efficiency in a number of different ways (e.g. through better optimization tools, increased availability of processes and more efficient maintenance management). However, there is not a clear link between digital strategies and energy efficiency measures in the energy intensive industries in Sweden. Moreover, energy efficiency is not considered the main driver for implementing digital technologies, it is rather considered a positive side effect. To accelerate the implementation of digital technologies it is important to support further research in this area and encourage a closer cooperation between stakeholders as well as mitigating challenges such as uncertainty regarding return on investment and issues related to data security and ownership.
Industrin är på väg in i en fjärde industriell revolution (Industri 4.0). Revolutionen möjliggörs av framsteg inom informations- och kommunikationsteknologier (digitalisering) och koncept som internet av saker och cyberfysiska system. Industri 4.0 förväntas ha en stor påverkan på tillverknings- och processindustrin, vilket kommer att förändra hur produkter utvecklas, produceras och säljs. Industri 4.0 är dock ett nytt koncept och dess effekter är fortfarande osäkra. I samband med att en allt strängare klimat- och energiagenda i Sverige sätter press på industrisektorn, är det viktigt att sektorn utnyttjar den fulla potentialen som Industri 4.0 kan bidrag med för en ökad hållbarhet. Det här examensarbetet analyserar det nuvarande läget för digitalisering inom de svenska energiintensiva industrierna (dvs. massa och pappers-, stål- och kemisk industrin) och hur det kan påverka energieffektiviteten i sektorn. Studien genomfördes med hjälp av kvalitativa forksningsmetoder. En litteraturstudie och fördjupade intervjuer med anställda inom branscherna genomfördes. Resultaten visar att trots att digitalisering anses vara viktig för de svenska energiintensiva industriernas framtida konkurrenskraft, anses sektorns digitala mognad inte vara hög. Digital teknik kan öka energieffektiviteten på ett antal olika sätt (t.ex. genom bättre optimeringsverktyg, ökad tillgänglighet av processer och effektivare underhållshantering). Det finns dock ingen tydlig koppling mellan digitala strategier och energieffektivitetsåtgärder i de energiintensiva industrierna i Sverige. Dessutom anses energieffektivitet inte vara den främsta drivkraften för att implementera digitala teknologier, utan anses snarare vara en positiv bieffekt. För att påskynda implementeringen av digital teknik är det viktigt att fortsätta stötta forskningen inom området och uppmuntra till ett närmare samarbete mellan olika aktörer samt bemöta utmaningar som osäkerheten kring framtida avkastningar på investeringar och frågor relaterade till datasäkerhet och ägande.

One of the legacies of the apartheid policies in South Africa has been·the huge gap between rich and poor households in terms of their access to basic energy services. This study explores the essence of shifting from· supply-driven approach to an integrated framework in energy planning order to evolve policies that match national goals and objectives with the energy needs of the low-income households. The principles of Integrated Energy Planning (IEP) are outline for the household sector and the development of an energy database is identified as one of the important processes required in IEP. The design of the database is practically demonstrated by capturing existing secondary and primary data on energy use in low-income households in South Africa. The user-interface and on-line data analysis of the database are also illustrated. Furthermore, the data has been extensively analysed to show the factors that influence energy demand in the low-income households and how these factors may interact with one another. In·addition, energy grid-use data·has been aggregated from the· database as input into an energy modelling computer programme for estimating energy demand projections for low-income households. These energy demand projections are based on 'energy scenarios which investigate alternate energy supply options. Thus the study illustrates how energy use data can be organised into a tool for informing policy formulation. Bibliography: p. 154-156.

The main aim of this thesis is investigating energy sustainability in developing countries using useful indicators. As it is known, serious issues such as global warming and inefficient consumption of energy will lead to severe problems in the future in the world and in particular in developing countries. Those countries which have a proper policy and practical actions by policymakers and energy experts can prevent these problems confidently. For these reasons, the present thesis has focused on developing indicators that can measure the grade of energy sustainability in order to achieve energy sustainability the countries analyzed. In this sense, the thesis starts to investigate the Sustainable Energy Development Index (SEDI) method and improves this method by finding and evaluating the useful indicators to improve and complete the SEDI methodology. In this regard, a numerical analysis of 12 countries has been realized. Following the methodology, new indicators associated with energy are proposed in line with the Habitat III and the SDGs from the UN. Additionally, appropriate strategies to combine the different UN goals are analyzed, and indicators are chosen to provide the best performance of the index. For this research, it is needed to analyze many related data and find novel indicators based on these data that can be obtained and applied by policymakers and energy experts for application in developing countries due to high percentage of energy consumption sector in these communities. Therefore, the main findings of this thesis are proposed indicators for improving the quality life of the inhabitants of different areas in the world with respect with the different aspects of the energy such as access energy, affordable energy and saving energy. For achieving to these goals, is the need to a correct policy, the evaluation of energy sustainability based on energy systems of a country, the close collaboration of policymakers with energy experts, using useful indicators, the balance of the energy supply, equity in access to energy and environmental sustainability of the urban and remote areas. These actions will lead to achieving energy sustainability confidently.
El objetivo principal de esta tesis es investigar la sostenibilidad energética en los países en desarrollo utilizando indicadores efectivos. Como es sabido, problemas como el calentamiento global y el consumo ineficiente de energía conducirán a serios problemas en el futuro del mundo y en particular en los países en desarrollo. Aquellos países que cuentan con políticas adecuadas y acciones efectivas por parte de los legisladores y expertos en energía pueden prevenir estos problemas con confianza. Por estas razones, la presente tesis se ha centrado en desarrollar indicadores que puedan medir el grado de sostenibilidad energética para lograr la sostenibilidad energética que los países analizaron. En este sentido, la tesis comienza a investigar el método del Índice de Desarrollo de Energía Sostenible (SEDI) y mejora este método al encontrar y evaluar los indicadores efectivos para mejorar y completar la metodología SEDI. En este sentido, se realizó un análisis numérico de 12 países. Siguiendo la metodología, se proponen nuevos indicadores asociados con la energía en línea con el Hábitat III y los ODS de la ONU. Además, se analizan las estrategias apropiadas para combinar los diferentes objetivos de las Naciones Unidas y se eligen los indicadores para proporcionar el mejor rendimiento del índice. Para esta investigación, es necesario analizar muchos datos relacionados y encontrar nuevos indicadores basados en estos datos que puedan ser obtenidos y aplicados por los formuladores de políticas y expertos en energía para su aplicación en los países en desarrollo debido al alto porcentaje del sector de consumo de energía en estas comunidades. Por lo tanto, los principales hallazgos de esta tesis son indicadores propuestos para mejorar la calidad de vida de los habitantes de diferentes áreas del mundo con respecto a los diferentes aspectos de la energía, como el acceso a la energía, la energía asequible y el ahorro de energía. Para alcanzar estos objetivos, se necesita corregir las políticas, la evaluación de la sostenibilidad energética basada en los sistemas energéticos de un país, la estrecha colaboración de los encargados de formular políticas con los expertos en energía, utilizando indicadores efectivos, el equilibrio del suministro de energía, la equidad en el acceso a sostenibilidad energética y ambiental de las zonas urbanas y remotas. Estas acciones conducirán a lograr la sostenibilidad energética con confianza.

Soaring energy demands are inevitable because of the continual increase in the global population as well as the greater reliance on electronic technologies. Current energy generation systems are highly dependent upon fossil fuels, for which the imminent risks and limitations are well known. First of all, we are confronting an energy crisis due to the depletion of these fossil fuels. However, current sustainable and renewable energy sources are not in a position to fully replace them as of yet. In fact, less than 10% of energy that is generated is from renewable energy sources, such as from hydroelectric power and solar power. Secondly, the emission of carbon dioxide (CO₂) and greenhouse gases (GhGs) from fossil fuels is currently at a serious level. As a result, today we are facing and experiencing abnormal climate changes. In order to mitigate and potentially resolve the energy crisis, energy generation systems are now shifting from fossil fuels to sustainable and renewable energy sources. Developments in energy harvesting technologies are considered to be a practical and promising way to deal with this crisis. Energy harvesting is a process that involves the generation of electrical energy by harnessing ambient environmental energy that is otherwise wasted. Generally, energy harvesting refers to a small amount of power for technologies such as portable electronic devices and wireless sensor networks. However, going forward, energy harvesting technologies beyond these would enable a bottom-up approach from 'the cell' scale to 'large farm' scale. My DPhil thesis deals with energy harvesting technologies that involve harnessing different environmental energy sources, such as solar and mechanical energy, using quantum dots for solar cells and polyvinylidene fluoride (PVDF)-based polymers for mechanical energy harvesting applications. Via novel approaches, such as the fabrication of a multi-junction quantum dot solar cell (QDSC) and the development of a room temperature polymer crystallisation method (solvent annealing), a significant enhancement in energy harvesting performance has been achieved. In addition, I have demonstrated more advanced energy harvesting devices by combining two alternative technologies together. Initially, a high efficiency QDSC is presented using the ferroelectric and piezoelectric coupling effect in PVDF-based polymer. Secondly, the integration of a QDSC with a mechanical energy harvester is demonstrated, which showed a combined enhancement by generating higher power beyond that observed from the individual components. Lastly, the thesis concludes with a demonstration of an application of these hybrid devices to self-powered electronics, which shows promise for future sustainable energy systems using energy harvesting technology.

Energy Performance Contracting is an energy saving method, when the supplier guarantees a certain minimal level of energy savings to the customer, as well as non-rising energy costs. The method was developed at the turn of 70's and 80's in the USA and has spread to dozens of countries around the world till today, although the rate of the EPC market development differs from country to country. The method is useful mostly for heating, electricity and gas cost savings by the end-users. In the Czech Republic, the method has been used since 1993. Until now, several dozens, or even hundreds of projects have been realized, mostly for public sector customers. This paper analyzes the current state of the EPC method usage around the world as well as in the Czech Republic, the key part comprises of the EPC principles description, based on data from real EPC contracts. The work is concluded by a SWOT analysis of the method and by a discussion of the following question: "Can EPC projects blockade the overall saving potential in some cases?" The key information source for most of the work were answers to questions sent to eight Czech ESCO companies representatives, as well as the outputs from guided interviews with four of them, which were taking place between January and May 2009.

This thesis is about Photovoltaic (PV) cells and its stresses in various directions by calculating the power generated using solar cells under different conditions to improve its efficiency. Our research studies found that using multi-junction cells with larger substrates can increase the efficiency to some extent which in practice is limited to 43 percent. The experiment was conducted using ten solar cells each with an area of 20.9〖cm〗 ^2, where each cell gives 0.5 V and 0.4 A and a 1.25 Ω resistor was used. The cells were connected in series. Once, the PV cells were fixed horizontally and the other time tested in tilted position under same outdoor condition. The purpose of testing PV cells was to investigate the efficiency under above mentioned conditions. The data collected from the readings was used in calculation, and we have obtained from the calculations that horizontally fixed cells gave 4.8 percent efficiency whereas tilted cells gave 6.6 percent efficiency. Hence, the ratio showed that fixed cells produced 37.5 percent more power compared to horizontally fixed cells. Our other experiment consisted of testing PV cells under different temperature conditions that was done using a freezer and an oven for temperature variation and a tungsten bulb was used as a light source. The purpose of performing this experiment was to investigate how the efficiency of PV cells is affected under extreme conditions. Part of our thesis was also including studies and analysis of produced energy by the solar panel installed on the roof of “BTH” building in Karlskrona, Sweden. The data consisted of energy produced from February up to August 2014. The investigation also included finding the highest produced energy during these months. We have found that the highest energy was generated on the 1st of July which was 12.86 kWh. Furthermore, we went deep into investigation of the 1st of July to know exactly which hour of that day the highest energy was produced. The data showed that the highest produced energy was at 12:19 and 13:19 which was 2.03 kWh.
Ramzi: +46723231353, +966561993488 Zain:

Information technology plays an increasingly important part in representing, managing, and driving the field of sustainable energy. However, current paradigms for representing much of this information can be fragmented, singular, and extremely domain focused. Linkage with wider concepts, for example between energy supply and demand data, can be minimal. This dissertation investigates ways in which such data linkages can be expanded upon, applying the latest concepts of Semantic Web technology to the area. This dissertation examines the role of the Semantic Web in representing information relevant to sustainable energy, with a particular focus on energy policy, energy supply, and the demands of the built environment. An approach for representing such information is outlined in the dissertation, which introduces new ontologies for representing energy policy and building information data and methodologies for modelling such data. Existing ontologies for representing energy supply are discussed, as are common connections between these areas and a server platform for knowledge storage and presentation. Additionally, some focus is directed towards the usability and accessibility of such data and the implementation of proof of concept applications targeted at specific areas within sustainable energy are presented. Using the outlined approach, energy information can be interlinked to allow multilevel data navigation from international policy data, through energy infrastructure, to individual energy demands, and ultimately to extremely detailed building component levels of granularity. Such data can be interlinked into wider linked data initiatives, increasing usefulness and expanding the scope for increased analysis. The implications of the outlined approach are discussed and evaluated with regard to various identified use cases requiring different levels of data granularity, in addition to impact on the wider domain of information management. This dissertation demonstrates, at a proof of concept level, that Semantic Web technology can be of significant benefit across the domain of sustainable energy.

BULL, EDWARD. Potential Energy. (Under the direction of Pat Rushin.) Potential Energy is a collection of sixteen short stories. They range from the fictional to the autofictional to the entirely non-fictional. In all of them, characters both real and imagined struggle to live and define themselves in a world that is outside their control. They cope with the inevitability of loss, dangers both internal and external, and the passing of their own greatness. Some of these characters become lost while others learn to embrace life on its own terms to accept  without hope or expectation. More often, they are not lost or enlightened, but simply survive to continue on, still uncertain. Though all the stories in Potential Energy are stand-alone, they are thematically connected. The themes of family and identity are most prominent in  Potential Energy and  Eulogy to Maria Mamani, Fire-Eater. Loss is confronted and the question of what comes next is asked in  Oysters and  Slide. The conflict between fate and the need for control rises to the surface in  Threshold,  The Elizabeth Years, and the non-fiction story of Charles Whitman s deadly rampage in 1966,  Seed. Themes of ambiguity, moral erosion, and literary exploitation appear in the non-fiction  Bright and Loud and Then Gone, about a landlord burned alive in Chicago in 2008, and  What It Might Have Been Like If We Had Been There, an apologetic for the writer s right to write inspired by the 2007 Al Mutanabbi Street car-bombing in Baghdad, Iraq. Most importantly all the content of Potential Energy tells stories of people trying to hold on to what is good when, tragically, everything must eventually come to an end.
M.F.A.
Department of English
Arts and Humanities
Creative Writing MFA

At school we were thought that if we include bulb in electrical circuit our battery will be discharging. The energy of battery will be spent to the lighting of bulb, however this theory gives us not correct imagination. This explanation implies that battery has some amount of energy and spend it on the bulb. Interesting but at the same time teacher shows us correct model of these process. Pay you attention that amperage in all circuit is the same. So the question is how much energy our bulb is spending during its work? The answer is zero. The energy is not spent it just converted from one form to another. So why battery cannot just maintain the work of bulb forever? When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33782

In the search for new energy resources, scientists have discovered ways to use the Earth itself as a valuable source of power. Geothermal power plants use the Earth’s natural underground heat to provide clean, renewable energy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33764

Hydrogen is the simplest element. An atom of hydrogen consists of only one proton and one electron. It's also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth - it's always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O). When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/13492

Artist Statement The urban environment of New York City is the source of inspiration for my prints and paintings. I am fascinated with the range of architecture and the intensity of sights and sounds. It is exhilarating for me to be in this setting that is ever changing and I want to share this excitement with the viewer. In my work, I layer photo transfers, stencils with acrylic paints, and printing inks to convey a sense of urban energy. I use a range of bright and bold colors that reflect my vivid memories of this environment. I also want to balance geometric and orderly structure with the chaos of crowded streets. The layering technique, mixed media approach, and scope of colors allow me to arrange and rearrange elements of the environment to express the excitement of the city landscape.

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 67-71).
Although energy efficiency has potential to be a significant energy resource in the United States, many energy efficiency projects continue to go unrealized. This is especially true in the residential sector, where efficiency programs, frequently administered by utilities, see very low participation rates. However, growing access to data and the growing prevalence of mapping technologies provide new avenues for introducing energy performance information in ways that could encourage increased energy efficiency implementation. Renters and homebuyers are increasingly using online interactive maps to inform their housing choices. If energy data is mapped or incorporated into an existing real estate map, energy efficiency could become a valued asset that influences housing decisions and encourages building upgrades by property owners. However, major obstacles remain in accessing the data necessary to create meaningful energy maps. Privacy is the most significant barrier to displaying building-level energy consumption and performance information. This thesis explores how an energy map could catalyze energy efficiency upgrades, specifically in the residential market. This research examines existing energy maps, existing energy assessment platforms and what data they use, and evaluates the state of energy data access in the United States. It seeks to answer what data is necessary to map building level energy performance, what policies are necessary to access that data, and how should energy information be displayed in a map for the most meaningful impact. This research suggests that State mandates may be necessary to access individual residential building energy data; that the Federal government should recommended a standardized platform, such as the Standard Energy Efficiency Data platform, to create a national standard for storing energy data and data taxonomy; and that an energy map will be most effective when displaying a relative energy performance score which could possibly be calculated from energy data and other publicly available building records.
by Alexis Howland.
M.C.P.

The aim of this thesis was to investigate the question of how to harvest RF energy and if we can harvest enough RF energy for it to be useful in an application. It is aimed towards sensor node applications, commonly used in a typical office environment. The WiFi band was chosen since it is omnipresent in the same environment. With the current development within wireless technology and the IoT domain the demand for low power electronic applications has increased and one of the challenges is to find efficient and sustainable ways of powering these types of devices.The best possible theoretical power content was initially calculated followed by measurements in an office. A circuit was designed containing an impedance matching network and rectifier. A measurement application was constructed using a microcontroller. Measurements were made in an office environment and the maximum harvested energy over 24 hours was 350 mJ. The energy was stored in a supercapacitor and is estimated to be enough to power a low energy sensor for about 30 seconds. A large part of the thesis is devoted to impedance matching involving calculating, simulating and experimenting to get a good result.
Med den nuvarande utvecklingen inom trådlös teknik och IoT-domänen har efterfrågan på elektroniska applikationer med låg effekt ökat och en av utmaningarna är att hitta effektiva och hållbara sätt att driva dessa typer av enheter. Syftet med detta projekt var att undersöka frågan hur vi skördar radiovågsenergi och kan vi skörda tillräckligt mycket med energi för att den ska vara användbar i en applikation. I ett typiskt kontor finns fler källor till radiovågor, däribland WiFi som antas ha en hög nyttjandegrad. Projektet valde att inrikta sig på WiFi bandet och undersöka om det går att utvinna tillräckligt med energi där.Projektet strävade efter att leverera en färdig produkt med alla ingående delar, en antenn, en likriktare, en lagringsenhet och ett matchningsnätverk för att anpassa antenn och likriktare till varandra. För att undersöka hur mycket energi som finns att skörda gjordes först beräkningar och sedan mätningar i bland annat ett typiskt kontor. Det konstaterades att det rör sig om väldigt låga nivåer och betonas att de apparater som använder WiFi klarar av att känna av signaler som är långt mycket lägre än de som krävs för att kunna utvinna energi. Detta innebär alltså att apparaterna kan kommunicera felfritt samtidigt som energiinnehållet är så lågt att det inte går att utvinna någon energi.Projektet ägnar stor del åt att optimera den impedansmatchning som måste ske mellan antenn och likriktare för att största möjliga effektutbyte ska kunna ske. Basen är ett kretskort med ett typiskt impedansnätverk och genom beräkningar, simuleringar och experiment tas en prototyp fram. För att kunna analysera resultaten används en mikrokontroller som tar de analoga värdena, omvandlar dem till digitala och skickar dem till en PC för analys.Mätningar gjordes i en kontorsmiljö och den maximala mängden energi som gick att utvinna var 350 mJ på 24 timmar. Energin lagrades i en superkondensator och bedöms vara tillräcklig för att driva en lågenergisensor i ca 30 sekunder.