Saving the planet but losing the landscape: the impact of renewable energy policies on rural Britain

The main instrument of the Government's renewable energy policy is to promote wind power through regulation and subsidy. This gives rise to anomalies in rural planning when turbines are erected in sensitve areas in which other forms of development are strictly controlled. The situation is reviewed in the context of economic viability and considered also against the alternative of growing fuel crops. The latter are currently hampered by lack of Government support but could fulfil a useful secondary role of sustaining the agricultural sector and with it the management of lowland landscapes.

Assessing the impact of occupant behaviour on the electricity consumption for lighting and small power in office buildings

Lighting and small power will typically account for more than half of the total electricity consumption in an office building. Significant variations in electricity used by different tenants suggest that occupants can have a significant impact on the electricity demand for these end-uses. Yet current modelling techniques fail to represent the interaction between occupant and the building environment in a realistic manner. Understanding the impact of such behaviours is crucial to improve the methodology behind current energy modelling techniques, aiming to minimise the significant gap between predicted and in-use performance of buildings. A better understanding of the impact of occupant behaviour on electricity consumption can also inform appropriate energy saving strategies focused on behavioural change. This paper reports on a study aiming to assess the intent of occupants to switch off lighting and appliances when not in use in office buildings. Based on the Theory of Planned Behaviour, the assessment takes the form of a questionnaire and investigates three predictors to behaviour individually: 1) behavioural attitude; 2) subjective norms; 3) perceived behavioural control. The paper details the development of the assessment procedure and discusses preliminary findings from the study. The questionnaire results are compared against electricity consumption data for individual zones within a multi-tenanted office building. Initial results demonstrate a statistically significant correlation between perceived behavioural control and energy consumption for lighting and small power

Decoupling of building energy use and climate

Energy use intensity (EUI) and climate have a well documented correlation, which is generally applied in building energy management. Green buildings have sought to greatly reduce energy consumption and a number of examples are documented in the literature. A sample of high performance buildings constructed in a variety of global locations is analyzed here, and provides evidence that measures to reduce energy consumption have reduced EUI to the point where its correlation with heating degree days is no longer apparent. This result suggests that end-user behaviour is the next major hurdle in lowering the energy consumption of greener buildings.

Control and chaos for vibro-impact and non-ideal oscillators

In the paper, we discuss dynamics of two kinds of mechanical systems. Initially, we consider vibro-impact systems which have many implementations in applied mechanics, ranging from drilling machinery and metal cutting processes to gear boxes. Moreover, from the point of view of dynamical systems, vibro-impact systems exhibit a rich variety of phenomena, particularly chaotic motion. In this paper, we review recent works on the dynamics of vibro-impact systems, focusing on chaotic motion and its control. The considered systems are a gear-rattling model and a smart damper to suppress chaotic motion. Furthermore, we investigate systems with non-ideal energy source, represented by a limited power supply. As an example of a non-ideal system, we analyse chaotic dynamics of the damped Duffing oscillator coupled to a rotor. Then, we show how to use a tuned liquid damper to control the attractors of this non-ideal oscillator.

Study of ethanol electro-oxidation in acid environment on Pt(3)Sn/C anode catalysts prepared by a modified polymeric precursor method under controlled synthesis conditions

A carbon-supported binary Pt(3)Sn catalyst has been prepared using a modified polymeric precursor method under controlled synthesis conditions This material was characterized using X-ray diffraction (XRD). and the results indicate that 23% (of a possible 25%) of Sn is alloyed with Pt, forming a dominant Pt(3)Sn phase. Transmission election microscopy (TEM) shows good dispersion of the electrocatalyst and small particle sizes (3 6 nm +/- 1 nm) The polarization curves for a direct ethanol fuel cell using Pt(3)Sn/C as the anode demonstrated Improved performance compared to that of a PtSn/C E-TEK. especially in the intrinsic resistance-controlled and mass transfer regions. This behavior is probably associated with the Pt(3)Sn phase. The maximum power density for the Pt(3)Sn/C electrocatalyst (58 mW cm(-2)) is nearly twice that of a PtSn/C E-TEK electrocatalyst (33 mW cm(-2)) This behavior is attributed to the presence of a mixed Pt(9)Sn and Pt(3)Sn alloy phase in the commercial catalysts (C) 2009 Elsevier B V All rights reserved

A dois passos do para��so?: an��lise sobre a constru����o da favela Parais��polis (S��o Paulo-SP) como destino tur��stico Rio de

Essa disserta����o versa sobre a constru����o da favela Parais��polis (S��o Paulo- SP) como destino tur��stico. Estev��o, Berbela e Antenor, moradores da favela, realizam ���trabalhos art��sticos��� que comp��em o elemento principal da atratividade tur��stica de Parais��polis. A partir do trabalho de campo, do tipo observa����o participante, descrevo os posicionamentos divergentes dos artistas, guias de turismo e a Uni��o de Moradores de Parais��polis. Aponto que esses posicionamentos geram disputas simb��licas e rela����es de poder entre os diversos atores envolvidos no processo de transforma����o de Parais��polis em um destino tur��stico. A inten����o principal �� entender como esse processo �� perpassado por conflitos, tanto de ordem econ��mica quanto de ordem pol��tica e ideol��gica. A perspectiva de an��lise tem como enfoque central as vis��es em disputa sobre o turismo e as pr��ticas que as tomam por base. Assim, procuro entender como os valores e pr��ticas locais se articulam com a����es e discursos ex��genos voltados para o desenvolvimento do turismo.

Desempenho de um painel fotovoltaico de baixa tens��o, acoplado ao prot��tipo de um conversor dc/dc topologia Booster

Low voltage solar panels increase the reliability of solar panels due to reduction of in series associations the configurations of photovoltaic cells. The low voltage generation requires DCDC converters devices with high efficiency, enabling raise and regulate the output voltage. This study analyzes the performance of a photovoltaic panel of Solarex, MSX model 77, configured to generate an open circuit voltage of 10.5 V, with load voltage of 8.5 V, with short circuit current of 9 A and a power of 77 W. The solar panel was assembled in the isolated photovoltaic system configuration, with and without energy storage as an interface with a DCDC converter, Booster topology. The converter was designed and fabricated using SMD (Surface Mounted Devices) technology IC (integrated circuit) that regulates its output voltage at 14.2 V, with an efficiency of 87% and providing the load a maximum power of 20.88 W. The system was installed and instrumented for measurement and acquisition of the following data: luminosities, average global radiation (data of INPE Instituto Nacional de Pesquisas Espaciais), solar panel and environment temperatures, solar panel and DC-DC converter output voltages, panel, inverter, and battery charge output currents. The photovoltaic system was initially tested in the laboratory (simulating its functioning in ideal conditions of operation) and then subjected to testing in real field conditions. The panel inclination angle was set at 5.5��, consistent with the latitude of Natal city. Factors such as climatic conditions (simultaneous variations of temperature, solar luminosities and ra diation on the panel), values of load resistance, lower limit of the maximum power required by the load (20.88 W) were predominant factors that panel does not operate with energy efficiency levels greater than 5 to 6%. The average converter efficiency designed in the field test reached 95%

M��todo da continua����o aplicado na an��lise de conting��ncia de linhas de transmiss��o

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Esquemas alternativos para o passo de parametriza����o do m��todo da continua����o baseados em par��metros f��sicos

O m��todo de fluxo de carga convencional �� considerado inadequado para se obter o ponto de m��ximo carregamento (PMC) de sistemas de pot��ncia, devido �� singularidade da matriz Jacobiana neste ponto. Os m��todos da continua����o s��o ferramentas eficientes para a solu����o deste tipo de problema, visto que t��cnicas de parametriza����o podem ser utilizadas para evitar a singularidade da matriz Jacobiana. Neste trabalho, novas op����es para a etapa de parametriza����o do m��todo da continua����o s��o apresentadas. Mostra-se que vari��veis com claro significado f��sico podem ser utilizadas na etapa de parametriza����o. As seguintes vari��veis foram testadas: perda total de pot��ncia ativa e reativa, pot��ncia ativa e reativa na barra de refer��ncia, pot��ncia reativa das barras de gera����o, e as perdas de pot��ncia ativa e reativa nas linhas de transmiss��o (LT). Al��m de facilitar a implementa����o computacional do m��todo de continua����o, as t��cnicas de parametriza����o apresentadas simplificam a defini����o matem��tica e o entendimento do m��todo por parte de engenheiros de pot��ncia, visto que os m��todos de continua����o existentes na literatura sempre utilizam t��cnicas de parametriza����o complexas, e de interpreta����o puramente geom��trica. Resultados obtidos com a nova metodologia para os sistemas testes do IEEE (14, 30, 57 e 118 barras) mostram que as caracter��sticas de converg��ncia do m��todo de fluxo de carga convencional s��o melhoradas na regi��o do PMC. Al��m disso, durante o tra��ado das curvas PV, as diversas t��cnicas de parametriza����o podem ser comutadas entre si possibilitando o c��lculo de todos os pontos da curva com um n��mero reduzido de itera����es. Diversos testes s��o realizados para proporcionar a compara����o do desempenho dos esquemas de parametriza����o propostos.

T��cnica de parametriza����o geom��trica para o fluxo de carga continuado baseado nas vari��veis tens��o nodal e fator de carregamento

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Determina����o do ponto de m��ximo carregamento de sistemas de pot��ncia utilizando o fluxo de carga desacoplado r��pido parametrizado

Os m��todos de fluxo de carga por Newton-Raphson e fluxo de carga desacoplado r��pido convencionais s��o considerados inadequados para a obten����o do ponto de m��ximo carregamento de sistemas de pot��ncia, devido �� problemas de mal-condicionamento neste ponto cr��tico e na sua vizinhan��a. Neste ponto a matriz Jacobiana do m��todo de Newton-Raphson torna-se singular e considera-se que n��o s��o mais v��lidas as hip��teses de desacoplamento P-V e Q-teta utilizadas para a formula����o do m��todo fluxo de carga desacoplado r��pido. No entanto, mostra-se neste trabalho, que com pequenas modifica����es, as vers��es XB e BX do fluxo de carga desacoplado r��pido tornam-se adequadas para a obten����o do ponto de m��ximo carregamento. Estas novas vers��es modificadas s��o comparadas entre si com o intuito de explicitar suas caracter��sticas, assim como da influ��ncia da atua����o dos limites de gera����o de pot��ncia reativa e de tap's de transformadores. Os resultados obtidos para os sistemas testes do IEEE (14, 30, 57 e 118 barras) mostram que as caracter��sticas de converg��ncia das vers��es originais s��o preservadas. Al��m disso, durante o tra��ado das curvas PV, os diversos m��todos podem ser comutados entre si possibilitando o c��lculo de todos os pontos da curva com um n��mero reduzido de itera����es.

Fluxo de carga continuado utilizando estrat��gia de parametriza����o geom��trica baseada em par��metros f��sicos

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Control and chaos for vibro-impact and non-ideal oscillators

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Continuation load flow using automatically determined branch megawatt losses as parameters

The conventional Newton's method is considered to be inadequate for the computation of the maximum loading point (MLP) of power systems since: (i) it encounters difficulties in the vicinity of the MLP: and (ii) the load flow Jacobian matrix becomes singular at the MLP. It is well known that continuation methods are powerful and useful tools that are able to trace the solution PV curve without experiencing such diffculties. However, continuation methods require a parameterisation so that a modified, well conditioned set of load flow equations is obtained. In particular, the Jacobian matrix associated with this modified set of equations should not be singular at the MLP. The authors propose that the actual power losses in transmission branches (lines and transformers) are used to parameterise the approach. Specific procedures for the automatic determination of the most appropriate parameter (branch) are proposed. Such procedures include the utilisation of fast voltage-stability indices. Simulation results are presented to show that the proposed method is able to trace the whole solution PV curve very efficiently.

Alternative continuation method for loading margin improvement and transmission losses reduction

This paper presents an alternative methodology for loading margin improvement and total real power losses reduction by using a continuation method. In order to attain this goal, a parameterizing equation based on the total real power losses and the equations of the reactive power at the slack and generation buses are added to the conventional power flow equations. The voltages at these buses are considered as control variables and a new parameter is chosen to reduce the real power losses in the transmission lines. The results show that this procedure leads to maximum loading point increase and consequently, in static voltage stability margin improvement. Besides, this procedure also takes to a reduction in the operational costs and, simultaneously, to voltage profile improvement. Another important result of this methodology is that the resulting operating points are close to that provided by an optimal power flow program. �� 2004 IEEE.