Communities of different sizes in Saskatchewan seeking economic opportunities have shown interest in ethanol production because of the perceived benefits a region can capture from such a project. In spite of this interest and the perceived benefits, no information on the type and magnitude of economic impacts which would accrue to different sized communities existed. This study was undertaken to fill this information gap by establishing facts on the economic impacts various levels of communities could capture from ethanol-cattle production complexes. Since Saskatchewan communities operate in a hierarchical fashion and are classified into seven levels using central place theory, questions concerning economic development should be viewed in a regional hierarchical framework. A seven-region hierarchically-based interregional input-output model for the Saskatchewan economy was constructed using the Supply-Demand Pool (SDP) method in combination with the logical assumptions regarding trade patterns within the central place region. It was assumed that higher-level regions are surplus regions in goods produced by non-primary sectors, and hence ship excess supply to producers and final users in the dominated lower-level regions and outside of the province. On the other hand, it was assumed that the hinterland region dominates trade in goods in the primary sectors. The hinterland earned income by producing and supplying goods and services in the primary sectors to the higher-level regions and outside the province. The model consisted of 14 aggregated sectors seven household sectors, and allowed for net flows of labour income through commuting patterns of workers who resided in the seven regions. At the same time the consumption expenditures of residents in a particular region were adjusted for outshopping purchases. The estimated model was used to assess the economic impacts from both the construction and operation phase of an integrated ethanol-cattle production complex across six hierarchical regions. The major findings of this study were that, under both phases of the project, intraregional output and labor income impacts occurring in the high level regions were larger than those in the lower-level regions. Also, the higher-level regions experienced larger interregional impacts and had spillover coefficients of smaller magnitude compared to lower-level regions. The intraregional output and labor income impacts tended to decrease as one moves down the hierarchy from top to bottom regions. On the other hand, the spillovers or leakages were increasing as one moves down the hierarchy from higher-level regions to lower-level regions. The higher-level regions have more diversified economies and smaller leakages of income and spending than lower-level regions. On the other hand, lower-level regions experienced large income leakages through input purchases and consumer spending in neighbouring higher-level regions. The results indicate that lower-level regions will not benefit more than higher-level regions from the development of an integrated ethanol-cattle production complex. Thus, if the goal of public funding of ethanol projects is to maximize impacts in the project-region, then higher-level regions would be preferred to lower-level regions. This raises a concern that the opportunity of pursuing regional development through ethanol processing may not reach all those communities who need it the most, especially the smaller communities. On the other hand, if the objective of rural development is to solve the problems of rural communities, the policy-makers, could target lower-level regions specially those experiencing economic decline. It is important to mention that integrated ethanol-cattle production continues to enjoy subsidies from the governments. (Abstract shortened by UMI.)

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The world is facing an energy crisis with worldwide energy consumption rising at an alarming rate. The effects that fossil fuels have on the environment are also causing concern. For these two reasons the world is determined to find ‘cleaner’, renewable and sustainable energy sources. The Cape Winelands District Munisipality (CWDM) area has been identified as the study area for a bioenergy project. The CWDM project aims to determine the possibility of producing bioenergy from lignocellulosic biomass, and transporting it as economically as possible to a number of electricity plants within the study area. From the CWDM project a number of research topics were identified. The aim of this thesis is to determine the best location for one or more processing plants that will maximise the potential profit through the entire system. This is achieved by minimising the overall life cycle cost of the project. It takes into account costs from establishing and maintaining the crops, harvesting, transportation, conversion and generation; with a strong focus on the transport costs. In conjunction with a Geographical Information Systems (GIS) specialist and taking into account various factors such as electricity demand, heat sales and substation locations, 14 possible plant locations were identified. The possible supply points for each of the 14 plant locations were then analysed by GIS again to yield data in terms of elevation, road distances and slope. The transport costs were calculated using the Vehicle Cost Schedule (VCS) from the Road Freight Association (RFA) and fuel consumption calculations. It takes into account slope, laden and unladen transport and considers different transport commodities. These calculations together with the other associated costs of the life cycle are then combined with the results of the GIS into an EXCEL file. From this a transportation optimisation model is developed and the equivalent yearly life cycle cost of each of the 14 demand points are minimised by means of LINGO software. Initially runs were done for 2.5 MW capacity plants. From the high profit areas identified here, a single area was chosen and further runs were done on it. These runs were performed to determine the effect of different plant capacities on the life cycle costs, as well as how it affects the farm gate price that can be paid to the farmer. It also determined the effect of farmer participation at different plant capacities. The results indicate that it is currently possible to pay a farmer between R 300.00 and R 358.00 for a ton of biomass. It also revealed that with higher participation from farmers in the CWDM project, lower costs and higher farm gate prices will result, since the transport costs will be lower. Although all the costs within the life cycle are variable over time, the transport cost is the only cost that varies spatially and this will have a major effect on the overall system cost. The thesis found that generating electricity from woody biomass is feasible for all areas that were considered as well as for all variations considered during the sensitivity analysis. For the recommended plant size of 5 MW the transport of logs will be optimum. / AFRIKAANSE OPSOMMING: Die tempo waarteen energieverbruik wêreldwyd styg is ʼn rede tot kommer. Die nadelige effek wat fossiel brandstowwe op die omgewing het, is ook ʼn probleem. Hierdie twee redes is hoofsaaklik wat die wêreld dryf om ‘skoner’ hernieubare en volhoubare energie bronne te vind. Die Kaapse Wynland Distrik Munisipaliteit (KWDM) area is identifiseer as ʼn studie area vir ʼn bio-energie projek. Die doel van die KWDM projek is om die vervaardiging van bio-energie vanaf plantasies, die vervoer van hierdie bome sowel as die prosessering koste by die fabriek te bepaal en te evalueer. Vanuit die KWDM projek het `n aantal tesisse ontwikkel waarvan hierdie een is. Die doel van hierdie tesis is om die beste posisie vir een of meer prosesserings fabrieke te bepaal wat die potensiële wins van die KWDM projek sal maksimeer. Dit is ook gemik daarop om die ekwivalente jaarlikse oorhoofse lewenssiklus koste van die projek te minimeer. Dit neem die vestiging en onderhoud van gewasse, oeskostes, vervoerkostes en proseskostes in ag, met ʼn spesifiek fokus op die vervoerkoste. In samewerking met `ʼn “Geographical Information Systems” (GIS) spesialis en deur verskeie faktore, soos elektrisiteitsverbruik, inkomste vanaf hitte verkope en substasie posisies, in ag te neem is 14 moontlike fabriek posisies identifiseer. Verder is die moontlike voorsienings areas van elk van die 14 fabriek posisies weer deur GIS analiseer om resultate in terme van hoogte bo seespieël, padafstand en helling te verkry. Die vervoerkostes is verkry vanaf die “Vehicle Cost Schedule” (VCS) van die “Road Freight Association” (RFA), asook berekeninge wat die brandstof verbruik in ag neem. Hierdie kostes sluit in die effek van gradiënt, gelaaide en ongelaaide vervoer sowel as verskillende vervoer produkte. Hierdie berekeninge sowel as die ander kostes in die siklus en die resultate van GIS is kombineer in ʼn EXCEL leer. Hierdie data word dan gebruik om ʼn LINGO model te ontwikkel en die oorhoofse lewenssiklus koste van elk van die 14 fabriek posisies te minimeer. Optimering is gedoen vir 2.5 MW kapasiteit fabrieke. Uit die beste areas is een area identifiseer en verdere lopies is daarop gedoen. Die doel van hierdie lopies is om die effek van verskillende fabriekskapasiteit op die lewensiklus koste te bepaal, asook die effek daarvan op die prys wat aan die boer betaal word vir hout. Hierdie lopies is ook gebruik om die effek van boer deelname te bepaal. Die resultaat dui aan dat dit tans moontlik is om ʼn boer tussen R 300.00 en R 358.00 te betaal vir ʼn ton biomassa. Dit het ook gewys dat hoe meer boere deelneem aan hierdie projek hoe laer is die oorhoofse lewensiklus koste en hoe hoër is die prys wat betaal kan word vir hout aangesien die vervoerkoste laer sal wees. Alhoewel al die lewensiklus kostes veranderlik is oor tyd, is dit net die vervoerkoste wat ʼn ruimtelike komponent ook het en dit sal ʼn groot effek op die oorhoofse lewenssiklus koste hê. Die tesis bevind dat dit lewensvatbaar is vir alle areas in die studie om elektrisiteit op te wek vanaf hout biomassa, selfs al word die uiterse variasie in die sensitiwiteitsanalise gebruik. Vir die aanbeveling van ʼn 5 MW fabriek sal die goedkoopste vervoer opsie boomstompe wees.

Made available in DSpace on 2014-06-11T19:31:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-14Bitstream added on 2014-06-13T18:42:31Z : No. of bitstreams: 1 costa_zf_dr_botfca.pdf: 1311668 bytes, checksum: 2974b8bf943c3e98c1292ae93a2e2934 (MD5) / O objetivo do presente trabalho foi analisar os índices de eficiência energética e econômica das explorações agropecuárias familiares cuja principal atividade é a produção de leite, na região de Botucatu-SP, especificamente no município de Pardinho-SP. Para melhor definição dos produtores familiares estudados foram utilizados os critérios do sistema oficial de crédito rural FEAP (Fundo de Expansão do Agronegócio Paulista). Por intermédio de dados primários, obtidos por relatos orais, foram reconstituídos os itinerários técnicos do agroecossistema de criação, detalhando as operações utilizadas. A partir de então, foram descritas as características de produção do sistema, possibilitando detalhar as máquinas, implementos, equipamentos, insumos e mão-de-obra utilizados. Assim, determinou-se as diversas exigências físicas e respectivos coeficientes técnicos. Estes, por sua vez, e acompanhando a literatura, foram transformados em unidades energéticas e econômicas que permitiram a determinação das relações estabelecidas entre “outputs” e “inputs” energéticos/econômicos presentes no agroecossistema pesquisado. Os resultados foram apresentados conforme o Sistema Internacional, ou seja, em unidades energéticas por unidades de área Megajoules por hectare (MJ . ha-1) e em unidades monetárias (R$ . ha-1). Como a hipótese que orienta este estudo é de que a relação energética pode ser coincidente com as relações econômicas buscou-se estudar os fluxos energéticos e econômicos apresentando-se por meio da estrutura de dispêndios, por tipo, fonte e forma de energia bruta, tanto do ponto de vista econômico quanto energético. Foram encontrados quatro produtores com diferentes itinerários técnicos, representando-se assim os dados separadamente, para melhor compreensão. O produtor um e dois... / The purpose of this study was to analyze the levels of efficiency energetics and economic operation of agricultural households whose main activity is the production of milk in the region of Botucatu, specifically the city of Pardinho-SP. For better definition of the family farmers studied were used criteria of the official system of rural credit FEAP (Fund Expansion of Agribusiness Paulista). Through primary data obtained through oral accounts were traced the routes technical to agroecosystem of creation, detailing the operations employed. Since then, were described the characteristics of the production system, detailing the machinery, implements, equipment, materials and manual labor used. Thus, determined the various physical requirements and their technical coefficients. these, in turn, and accompanying literature, were transformed into units energetic and economic that allowed to determine the relationship between outputs and inputs energetic/economic in the agroecosystem studied. The results were presented as the International System, ie, in units energy per unit area MegaJoules per hectare (MJ . ha-1) and currency units (R$ . ha-1). Since the hypothesis that guides this study is that the energy relationship may be coincidental with the economic relations aimed to study the energy and economic flows is presented through the structure of expenditures, by type, source and form, and gross energy, both economically and energy. We found four producers with different technical routes, thus representing the data separately for better understanding. The producer who obtained are higher rate... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:24:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-11-11Bitstream added on 2014-06-13T19:52:17Z : No. of bitstreams: 1 romero_mgc_me_botfca.pdf: 501966 bytes, checksum: 8a2162abca05fd26e5b11cd59e8f4957 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O presente trabalho objetivou avaliar índices de eficiência energética e econômica por unidade de área do agroecossistema algodão, em determinado sistema de produção familiar e estabelecer a relação entre a eficiência energética e a eficiência econômica. A hipótese que orienta este estudo é de que a relação energética pode ser coincidente com as relações econômicas. Como ponto de enfoque desta pesquisa é analisada a exploração familiar, utilizando-se a categorização realizada pelo Programa Nacional de Fortalecimento da Agricultura Familiar (PRONAF). A cultura de algodão tem-se destacado na agricultura brasileira por sua importância econômica e social. Sendo assim, considerou-se a importância desta cultura e observou-se a sua participação na produção agrícola familiar. Foram utilizados dados primários de três explorações familiares do município de Leme/SP. Na construção da estrutura de dispêndios energéticos do agroecossistema algodão bem como na avaliação da eficiência econômica, considerou-se os valores médios obtidos, em função destes agricultores apresentarem o mesmo itinerário técnico e estarem dentro da tipificação utilizada neste trabalho. Os resultados da eficiência energética foram apresentados pela estrutura de dispêndios energéticos, por tipo, fonte e forma e energia bruta. Do ponto de vista econômico, os indicadores de eficiência foram apresentados na forma de distribuição de freqüência de probabilidade. Considerando-se o agroecossistema algodão a partir do itinerário técnico apresentado, observou-se uma energia bruta do produto igual a 37.138,59 MJ . ha-1, com uma participação de 34,21% e 65,79% das energias direta e indireta, respectivamente. O agroecossistema estudado dependeu fundamentalmente de fonte de energia industrial, particularmente inseticidas (39,71%) e fertilizantes químicos (19,88%) e de fontes... / The aim of this study was to assess the energy and economic efficiency indexes per unit of cotton agro-ecosystem area, in a certain system of family production and to establish a ratio between energy efficiency and economic efficiency. The hypothesis that guides this study is that the energy ratio cannot be coincident with the economic ratios. As the focal point of this research, family exploitation is analyzed, with the use of the categorization done by the National Program for Strengthening Family Agriculture - (Programa Nacional de Fortalecimento da Agricultura Familiar - PRONAF). Cotton planting has been outstanding in Brazilian agriculture because of its economic and social importance. Thus, the importance of this crop was considered, and its participation in family agricultural production observed. Use was made of primary data from three family exploitations in the municipality of Leme/SP, Brazil. To construct the energy expenditure structure of the cotton agro-ecosystem, as well as to assess the economic efficiency, the mean values obtained were considered, since these agriculturalists present the same technical itinerary and are within the typification proposed in this study. The energy efficiency results were presented by the energy expenditure structure by type, source, form and gross energy. From the economic point of view, the efficiency indexes were presented in the form of frequency and probability distribution. Considering the cotton agro ecosystem from the technical itinerary presented, a gross product energy equal to 37.138,59 MJ . ha-1 was observed, with a participation of 34,21% and 65,79% of the direct and indirect energy respectively. The studied agro ecosystem fundamentally depended on the industrial source of energy, particularly insecticides (39,71%) and chemical fertilizers (19,88%) and fossil sources (33,80%)...(Complete abstract click electronic access below)

The major topic of this master‘s thesis is to create a complex model of general photovoltaic power plant (PVP). First chapters are engaged in research of photovoltaic. Growth of globally installed power and analysis of situation in Czech Republic are described in this section. The spectrum of conditions is introduced, from current legislative framework up to local Sun radiation. The actual technologies and their advantages are depicted, especially rate of utilization of energy. Expected trends of future development of conversion efficiency are mentioned, with prediction of production costs of photovoltaic. In context with those aspects, the question of grid parity achievement arises. The own assembled model of photovoltaic power plant has been created in Microsoft Excel. The mathematical apparatus is described in a separate chapter, individually solving technical part, which main result – the amount of yearly generated electricity, is applied for economical calculation. Final results are the usual economic indicators, mainly: Net Present Value (NPV), Internal Rate of Return (IRR), Levelized Cost of Electricity (LCOE). There is series of aspects defined by user in the model which may impact the amount of produced electricity and economics of user’s project, such as use of loan, replacement of converters, operational costs etc. These aspects are frequently neglected by project sellers. In the end, intended photovoltaic power plants of 2.75 kWp and 28.98 kWp are simulated by the model in real conditions of 2013. Sensitivity of impact of both proposals to the aspects mentioned above has been analyzed. In the conclusion the achieved results are summarized and the key factors which determine the PVP’s economic efficiency are assessed.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1975. / Vita. / Bibliography: leaves 460-462. / by Raymond Eng. / Ph.D.

Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: Climate change that results from greenhouse gases (GHG’s) released from the burning of fossil fuels, together with the rising price of oil, have sparked interest in renewable biofuels. The production of biofuels also presents potential socio-economic benefits. There are two types of technologies for bioethanol production: · First generation bioethanol is produced from food feedstocks such as juice of sugarcane. · Second generation bioethanol is produced from non-food feedstocks (lignocellulosic materials). This project is concerned with 1st and 2nd generation bioethanol production from sugarcane juice and bagasse and the integration of these technologies. This project comprises a combination of experimental and process modelling work to assess energy efficiencies and the economic viability of integrated and stand-alone processes in the sub-Saharan African context. First generation fermentation experiments were conducted and high ethanol concentrations of up to 113.7 g/L were obtained. It was concluded that a recombinant yeast strain may be able to replace a natural hexose fermenting yeast for 1st generation fermentations to reduce costs. 2nd generation fermentation experiments were performed and ethanol concentrations of close to 40 g/L were obtained. Combinations of 1st and 2nd generation fermentation experiments were performed to improve the 2nd generation fermentation. In one of the experiments it was concluded that the combination of 1st and 2nd generation fermentations significantly improved the 2nd generation fermentation with an overall ethanol concentration of 57.6 g/L in a shorter time than for the pure 2nd generation experiments. It was determined from washing and pressing experiments that pressing the pre-hydrolysate liquor out of the pre-treated bagasse will sufficiently lower the levels of inhibitors in a 2nd generation fermentation when using a hardened yeast. Some of the data from the 1st generation experiments were used along with literature data to model a first generation process in Aspen Plus® which processes 493 tons of cane per hour (tc/hr). Pinch heat integration was used to reduce the utility requirements. The process used the bagasse that was generated to co-produce steam and electricity. The excess electricity was sold for additional revenue. In one scenario the excess bagasse was determined at 57.5%. This bagasse was sold to a stand-alone 2nd generation plant. The first generation process produced 85.5 litres of ethanol per ton of cane (L/tc), the integrated process produced 128 L/tc while the stand-alone 2nd generation process produced 185 litres of ethanol per ton of bagasse (50% moisture) or 25.5 L/tc. The amount of excess electricity that was produced ranged from 14.3 to 70.2 kWh/tc. Economic analyses were performed using South African economic parameters to resemble the sub- Saharan African context. Data from the 1st generation process model and literature data for integrated 1st and 2nd generation and stand-alone 2nd generation processes were used for the analyses. It was found that the integrated plant is the most economically viable (IRR = 11.66%) while the 1st generation process basically broke even (IRR = 1.62%) and the 2nd generation process is unviable. This was as a result of high sugarcane prices and too few incentives for 2nd generation ethanol. / AFRIKAANSE OPSOMMING: Klimaatsverandering wat veroorsaak word deur kweekhuisgasse wat vrygestel word deur die verbranding van fossielbrandstowwe en die stygenede olieprys het belangstelling in hernubare biobrandstowwe laat opvlam. Die produksie van biobrandstowwe hou ook potensiële sosioekonomiese voordele in. Daar is twee tegnologieë vir bioetanol produksie: · Eerste generasie bioetanol word vanaf voedsel bronne soos suikersap geproduseer. · Tweede generasie bioetanol word van nie-voedsel bronne (lignosellulose materiaal) geproduseer. Hierdie projek handel oor 1ste en 2de generasie bioetanol produksie van suikersap en suikerriet bagasse en die integrasie van hierdie tegnologieë. Hierdie projek bestaan uit ‘n kombinasie van eksperimentele- en prosesmodellering werk om die energiedoeltreffendheid en ekonomise vatbaarheid van geïntegreerde en alleenstaande prosesse in die sub-Sahara konteks te ondersoek. Eerste generasie fermentasie eksperimente is uitgevoer en hoë etanol konsentrasies van tot 113.7 g/L is gekry. Dit was bepaal dat ‘n rekombinante gisras ‘n natuurilke heksose fermenterende gisras kan vervang vir 1ste generasie fermentasies om kostes te bespaar. 2de generasie fermentasie eksperimente is gedoen en etanol konsentrasies van amper 40 g/L is behaal. Kombinasies van 1ste en 2de generasie fermentasie-eksperimente was uitgevoer om die 2de generasie fermentasie te verbeter. In een van die eksperimente is dit bepaal dat die kombinasie van 1ste en 2de generasie fermentasie die 2de generasie fermentasie beduidend verbeter het met ‘n etanol konsentrasie van 57.6 g/L en dít in ‘n korter tyd as vir die suiwer 2de generasie eksperimente. Dit was bepaal vanuit pers- en was eksperimente dat om die pre-hidrolisaat vloeistof uit die stoombehandelde bagasse te pers, die vlak van inhibitore in ‘n 2de generasie fermentasie voldoende verlaag vir die gebruik van ‘n verharde gis. Van die data van die 1ste generasie eksperimente was saam met literatuurdata gebruik om ‘n 1ste generasie proses in Aspen Plus® te modelleer wat 493 ton suikerriet per uur prosesseer (tc/hr). Pinch hitte integrasie was gebruik om die dienste vereistes te verminder. In die proses word die bagasse gebruik om stoom en elektrisiteit te genereer. In een geval was die oortillge bagasse bepaal as 57.5%. Hierdie bagasse was verkoop aan ‘n alleenstaande 2de generasie aanleg. Die eerste generasie proses het 85.5 liter etanol per ton suikerriet geproduseer (L/tc), die geïntegreerde proses het 128 L/tc geproduseer terwyl die 2de generasie proses 185 liter etanol etanol per ton bagasse (50% vog) of 25.5 L/tc geproduseer het. Die hoeveelhede oortillige elektrisiteit wat geproduseer is wissel van 14.3 tot 70.2 kWh/tc. Ekonomiese analieses is gedoen met Suid-Afrikaanse ekonomiese parameters om die sub-Sahara Afrika-konteks uit te beeld. Data van die 1ste generasie prosesmodel en literatuurdata van geïntegreerde 1ste en 2de generasie en alleenstaande 2de generasie prosesse was vir die analieses gebruik. Dit is bepaal dat die geïntegreerde model die mees ekonomies vatbare model is (IRR = 11.66%) terwyl die 1ste generasie proses basies gelyk gebreek het (IRR = 1.62%) en die 2de generasie proses is ekonomies onvatbaar. Hierdie bevindinge is as gevolg van hoë suikerrietpryse en te min aansporings vir 2de generasie etanol.

Apoiando-se na análise da discussão em torno do efeito bumerangue, fenômeno pelo qual ganhos de eficiência energética desencadeiam incentivo a maior consumo de energia, esta dissertação busca compreender qual tem sido a função deste recurso dentro de estruturas capitalistas de desenvolvimento. Busca-se esta compreensão pela análise de argumentos e evidências levantados na literatura específica que apóia ou opõe-se à adoção de políticas de eficientização. Além disso, desenvolve-se uma análise empírica alternativa com o intuito de avaliar o peso de argumentos que são utilizados como questionamentos à adoção de tais políticas. Neste trabalho, o debate em torno das políticas de eficientização é visto como uma oportunidade para aperfeiçoar o entendimento sobre a relação entre energia, inovação tecnológica e desenvolvimento sócio-econômico. / Supporting itself in the analysis of the discussion around of the rebound effect, phenomenon by the which gains on energetic efficiency unchain incentive to more energy requirements, this dissertation looks forward to understand which it has been the function of this factor inside capitalist structures of development. This is searched through the analysis of evidences and arguments lifted in the specific literature supporting or not efficiency policies adoption. Moreover, an alternative empiric analysis is also developed in order to evaluate the positions against the adoption of such policies. In this work, the debate around efficiency policies is seen as an opportunity to improve the understanding of the relation between energy, technological innovation and socioeconomic development.

Resumo: O presente trabalho objetivou avaliar índices de eficiência energética e econômica por unidade de área do agroecossistema algodão, em determinado sistema de produção familiar e estabelecer a relação entre a eficiência energética e a eficiência econômica. A hipótese que orienta este estudo é de que a relação energética pode ser coincidente com as relações econômicas. Como ponto de enfoque desta pesquisa é analisada a exploração familiar, utilizando-se a categorização realizada pelo Programa Nacional de Fortalecimento da Agricultura Familiar (PRONAF). A cultura de algodão tem-se destacado na agricultura brasileira por sua importância econômica e social. Sendo assim, considerou-se a importância desta cultura e observou-se a sua participação na produção agrícola familiar. Foram utilizados dados primários de três explorações familiares do município de Leme/SP. Na construção da estrutura de dispêndios energéticos do agroecossistema algodão bem como na avaliação da eficiência econômica, considerou-se os valores médios obtidos, em função destes agricultores apresentarem o mesmo itinerário técnico e estarem dentro da tipificação utilizada neste trabalho. Os resultados da eficiência energética foram apresentados pela estrutura de dispêndios energéticos, por tipo, fonte e forma e energia bruta. Do ponto de vista econômico, os indicadores de eficiência foram apresentados na forma de distribuição de freqüência de probabilidade. Considerando-se o agroecossistema algodão a partir do itinerário técnico apresentado, observou-se uma energia bruta do produto igual a 37.138,59 MJ . ha-1, com uma participação de 34,21% e 65,79% das energias direta e indireta, respectivamente. O agroecossistema estudado dependeu fundamentalmente de fonte de energia industrial, particularmente inseticidas (39,71%) e fertilizantes químicos (19,88%) e de fontes...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to assess the energy and economic efficiency indexes per unit of cotton agro-ecosystem area, in a certain system of family production and to establish a ratio between energy efficiency and economic efficiency. The hypothesis that guides this study is that the energy ratio cannot be coincident with the economic ratios. As the focal point of this research, family exploitation is analyzed, with the use of the categorization done by the National Program for Strengthening Family Agriculture - ("Programa Nacional de Fortalecimento da Agricultura Familiar - PRONAF"). Cotton planting has been outstanding in Brazilian agriculture because of its economic and social importance. Thus, the importance of this crop was considered, and its participation in family agricultural production observed. Use was made of primary data from three family exploitations in the municipality of Leme/SP, Brazil. To construct the energy expenditure structure of the cotton agro-ecosystem, as well as to assess the economic efficiency, the mean values obtained were considered, since these agriculturalists present the same technical itinerary and are within the typification proposed in this study. The energy efficiency results were presented by the energy expenditure structure by type, source, form and gross energy. From the economic point of view, the efficiency indexes were presented in the form of frequency and probability distribution. Considering the cotton agro ecosystem from the technical itinerary presented, a gross product energy equal to 37.138,59 MJ . ha-1 was observed, with a participation of 34,21% and 65,79% of the direct and indirect energy respectively. The studied agro ecosystem fundamentally depended on the industrial source of energy, particularly insecticides (39,71%) and chemical fertilizers (19,88%) and fossil sources (33,80%)...(Complete abstract click electronic access below) / Orientador: Osmar de Carvalho Bueno / Coorientador: Maura Seiko Tsutsui Esperancini / Banca: Valéria Comitre / Banca: Andréa Eloisa Bueno Pimentel / Mestre

Apoiando-se na análise da discussão em torno do efeito bumerangue, fenômeno pelo qual ganhos de eficiência energética desencadeiam incentivo a maior consumo de energia, esta dissertação busca compreender qual tem sido a função deste recurso dentro de estruturas capitalistas de desenvolvimento. Busca-se esta compreensão pela análise de argumentos e evidências levantados na literatura específica que apóia ou opõe-se à adoção de políticas de eficientização. Além disso, desenvolve-se uma análise empírica alternativa com o intuito de avaliar o peso de argumentos que são utilizados como questionamentos à adoção de tais políticas. Neste trabalho, o debate em torno das políticas de eficientização é visto como uma oportunidade para aperfeiçoar o entendimento sobre a relação entre energia, inovação tecnológica e desenvolvimento sócio-econômico. / Supporting itself in the analysis of the discussion around of the rebound effect, phenomenon by the which gains on energetic efficiency unchain incentive to more energy requirements, this dissertation looks forward to understand which it has been the function of this factor inside capitalist structures of development. This is searched through the analysis of evidences and arguments lifted in the specific literature supporting or not efficiency policies adoption. Moreover, an alternative empiric analysis is also developed in order to evaluate the positions against the adoption of such policies. In this work, the debate around efficiency policies is seen as an opportunity to improve the understanding of the relation between energy, technological innovation and socioeconomic development.