871 resultados para Low-carbon economy
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Food processing industry generates substantial high organic wastes along with high energy uses. The recovery of food processing wastes as renewable energy sources represents a sustainable option for the substitution of fossil energy, contributing to the transition of food sector towards a low-carbon economy. This article reviews the latest research progress on biofuel production using food processing wastes. While extensive work on laboratory and pilot-scale biosystems for energy production has been reported, this work presents a review of advances in metabolic pathways, key technical issues and bioengineering outcomes in biofuel production from food processing wastes. Research challenges and further prospects associated with the knowledge advances and technology development of biofuel production are discussed.
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Due to growing concerns regarding the anthropogenic interference with the climate system, countries across the world are being challenged to develop effective strategies to mitigate climate change by reducing or preventing greenhouse gas (GHG) emissions. The European Union (EU) is committed to contribute to this challenge by setting a number of climate and energy targets for the years 2020, 2030 and 2050 and then agreeing effort sharing amongst Member States. This thesis focus on one Member State, Ireland, which faces specific challenges and is not on track to meet the targets agreed to date. Before this work commenced, there were no projections of energy demand or supply for Ireland beyond 2020. This thesis uses techno-economic energy modelling instruments to address this knowledge gap. It builds and compares robust, comprehensive policy scenarios, providing a means of assessing the implications of different future energy and emissions pathways for the Irish economy, Ireland’s energy mix and the environment. A central focus of this thesis is to explore the dynamics of the energy system moving towards a low carbon economy. This thesis develops an energy systems model (the Irish TIMES model) to assess the implications of a range of energy and climate policy targets and target years. The thesis also compares the results generated from the least cost scenarios with official projections and target pathways and provides useful metrics and indications to identify key drivers and to support both policy makers and stakeholder in identifying cost optimal strategies. The thesis also extends the functionality of energy system modelling by developing and applying new methodologies to provide additional insights with a focus on particular issues that emerge from the scenario analysis carried out. Firstly, the thesis develops a methodology for soft-linking an energy systems model (Irish TIMES) with a power systems model (PLEXOS) to improve the interpretation of the electricity sector results in the energy system model. The soft-linking enables higher temporal resolution and improved characterisation of power plants and power system operation Secondly, the thesis develops a methodology for the integration of agriculture and energy systems modelling to enable coherent economy wide climate mitigation scenario analysis. This provides a very useful starting point for considering the trade-offs between the energy system and agriculture in the context of a low carbon economy and for enabling analysis of land-use competition. Three specific time scale perspectives are examined in this thesis (2020, 2030, 2050), aligning with key policy target time horizons. The results indicate that Ireland’s short term mandatory emissions reduction target will not be achieved without a significant reassessment of renewable energy policy and that the current dominant policy focus on wind-generated electricity is misplaced. In the medium to long term, the results suggest that energy efficiency is the first cost effective measure to deliver emissions reduction; biomass and biofuels are likely to be the most significant fuel source for Ireland in the context of a low carbon future prompting the need for a detailed assessment of possible implications for sustainability and competition with the agri-food sectors; significant changes are required in infrastructure to deliver deep emissions reductions (to enable the electrification of heat and transport, to accommodate carbon capture and storage facilities (CCS) and for biofuels); competition between energy and agriculture for land-use will become a key issue. The purpose of this thesis is to increase the evidence-based underpinning energy and climate policy decisions in Ireland. The methodology is replicable in other Member States.
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The Biospheric Project is a nested multi-scalar urban agriculture project that aims to develop sustainable food systems in disadvantaged communities, though not only physical interventions, such as the urban masterplan and neighbourhood design to the building and its roof and façade, but also through social and commercial interventions, such as community involvement, businesses and a distribution system.
The project is focused around the Biospheric Foundation, a community interest company and research think-tank whose aim is to hasten our transition to a closed cycle, low-carbon economy. Its home is Irwell house, that houses a large-scale aquaponic-based food production system, which is directly linked to a whole-food shop (78 Steps, named after the distance from the productive system) and a whole food distribution system (the Whole Box). The building sits within a post-industrial landscape which is being developed into a new productive landscape, utilizing the the technologies developed by the Biospheric Foundation and Prof Greg Keeffe of Queens University Belfast. The collaboration links designer, academics and activists across the disciplines of Urban design, Architecture, Permaculture, landscape design, environmental science and business and community.
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Wind energy has been identified as key to the European Union’s 2050 low carbon economy. However, as wind is a variable resource and stochastic by nature, it is difficult to plan and schedule the power system under varying wind power generation. This paper investigates the impacts of offshore wind power forecast error on the operation and management of a pool-based electricity market in 2050. The impact of the magnitude and variance of the offshore wind power forecast error on system generation costs, emission costs, dispatch-down of wind, number of start-ups and system marginal price is analysed. The main findings of this research are that the magnitude of the offshore wind power forecast error has the largest impact on system generation costs and dispatch-down of wind, but the variance of the offshore wind power forecast error has the biggest impact on emissions costs and system marginal price. Overall offshore wind power forecast error variance results in a system marginal price increase of 9.6% in 2050.
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Power has become a key constraint in current nanoscale integrated circuit design due to the increasing demands for mobile computing and a low carbon economy. As an emerging technology, an inexact circuit design offers a promising approach to significantly reduce both dynamic and static power dissipation for error tolerant applications. Although fixed-point arithmetic circuits have been studied in terms of inexact computing, floating-point arithmetic circuits have not been fully considered although require more power. In this paper, the first inexact floating-point adder is designed and applied to high dynamic range (HDR) image processing. Inexact floating-point adders are proposed by approximately designing an exponent subtractor and mantissa adder. Related logic operations including normalization and rounding modules are also considered in terms of inexact computing. Two HDR images are processed using the proposed inexact floating-point adders to show the validity of the inexact design. HDR-VDP is used as a metric to measure the subjective results of the image addition. Significant improvements have been achieved in terms of area, delay and power consumption. Comparison results show that the proposed inexact floating-point adders can improve power consumption and the power-delay product by 29.98% and 39.60%, respectively.
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Electric vehicles (EVs) and hybrid EVs are the way forward for green transportation and for establishing low-carbon economy. This paper presents a split converter-fed four-phase switched reluctance motor (SRM) drive to realize flexible integrated charging functions (dc and ac sources). The machine is featured with a central-tapped winding node, eight stator slots, and six rotor poles (8/6). In the driving mode, the developed topology has the same characteristics as the traditional asymmetric bridge topology but better fault tolerance. The proposed system supports battery energy balance and on-board dc and ac charging. When connecting with an ac power grid, the proposed topology has a merit of the multilevel converter; the charging current control can be achieved by the improved hysteresis control. The energy flow between the two batteries is balanced by the hysteresis control based on their state-of-charge conditions. Simulation results in MATLAB/Simulink and experiments on a 150-W prototype SRM validate the effectiveness of the proposed technologies, which may provide a solution to EV charging issues associated with significant infrastructure requirements.
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The transition to a low-carbon economy urgently demands better information on the drivers of energy consumption. UK government policy has prioritized energy efficiency in the built stock as a means of carbon reduction, but the sector is historically information poor, particularly the non-domestic building stock. This paper presents the results of a pilot study that investigated whether and how property and energy consumption data might be combined for non-domestic energy analysis. These data were combined in a ‘Non-Domestic Energy Efficiency Database’ to describe the location and physical attributes of each property and its energy consumption. The aim was to support the generation of a range of energy-efficiency statistics for the industrial, commercial and institutional sectors of the non-domestic building stock, and to provide robust evidence for national energy-efficiency and carbon-reduction policy development and monitoring. The work has brought together non-domestic energy data, property data and mapping in a ‘data framework’ for the first time. The results show what is possible when these data are integrated and the associated difficulties. A data framework offers the potential to inform energy-efficiency policy formation and to support its monitoring at a level of detail not previously possible.
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This paper explores the possible evolution of UK electricity demand as we move along three potential transition pathways to a low carbon economy in 2050.The shift away from fossil fuels through the electrification of demand is discussed, particularly through the uptake of heat pumps and electric vehicles in the domestic and passenger transport sectors. Developments in the way people and institutions may use energy along each of the pathways are also considered and provide a rationale for the quantification of future annual electricity demands in various broad sectors. The paper then presents detailed modelling of hourly balancing of these demands in the context of potential low carbon generation mixes associated with the three pathways. In all cases, hourly balancing is shown to be a significant challenge. To minimise the need for conventional generation to operate with very low capacity factors, a variety of demand side participation measures are modelled and shown to provide significant benefits. Lastly, projections of greenhouse gas emissions from the UK and the imports of fossil fuels to the UK for each of the three pathways are presented.
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The construction sector has a major role to play in delivering the transition to a low carbon economy and in contributing to sustainable development; however, integrating sustainability into everyday business remains a major challenge for the sector. This research explores the experience of three large construction and engineering consultancy firms in mainstreaming sustainability. The aim of the paper is to identify and explain variations in firm level strategies for mainstreaming sustainability. The three cases vary in the way in which sustainability is ramed – as a problem of risk, business opportunity or culture – and in its location within the firm. The research postulates that the mainstreaming of sustainability is not the uniform linear process often articulated in theories of strategic change and management, but varies with the dominant organisational culture and history of each firm. he paper concludes with a reflection on the implications of this analysis for management theories and for firm level strategies.
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There is general agreement across the world that human-made climate change is a serious global problem,although there are still some sceptics who challenge this view. Research in organization studies on the topic is relatively new. Much of this research, however, is instrumental and managerialist in its focus on ‘win-win’ opportunities for business or its treatment of climate change as just another corporate social responsibility (CSR) exercise. In this paper, we suggest that climate change is not just an environmental problem requiring technical and managerial solutions; it is a political issue where a variety of organizations – state agencies, firms, industry associations, NGOs and multilateral organizations – engage in contestation as well as collaboration over the issue. We discuss the strategic, institutional and political economy dimensions of climate change and develop a socioeconomic regimes approach as a synthesis of these different theoretical perspectives. Given the urgency of the problem and the need for a rapid transition to a low-carbon economy, there is a pressing need for organization scholars to develop a better understanding of apathy and inertia in the face of the current crisis and to identify paths toward transformative change. The seven papers in this special issue address these areas of research and examine strategies, discourses, identities and practices in relation to climate change at multiple levels.
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Ao longo dos últimos anos, através do aprimoramento das políticas agrícolas, observaram-se aumentos consistentes dos recursos orçamentários destinados à Agricultura Familiar, através do Pronaf. O incremento dos recursos efetivamente aplicados e o número cada vez maior de contratos também são realidade e podem ser vistos em todas as regiões do País. De acordo com os dados divulgados pelo Banco Central do Brasil, através do Anuário Estatístico do Crédito Rural (2014), foram aplicados no Brasil em 2004 aproximadamente R$ 4,39 bilhões, já em 2012 foram pouco mais de R$ 16,35 bilhões, ou seja, incremento de 272% no intervalo analisado. Em relação ao número de contratos, o crescimento foi em torno de 35,5% no mesmo período. A importância da Agricultura Familiar no contexto atual é corroborada no âmbito internacional pela Resolução 66/222, de 28.03.2012, da Assembleia-Geral, que conferiu à Organização das Nações Unidas para Alimentação e Agricultura (FAO) o mandato de implementar o Ano Internacional da Agricultura Familiar (AIAF) neste ano de 2014, em parceria com os governos dos países membros bem como com outros organismos internacionais e organizações não-governamentais atuantes no tema da agricultura e da segurança alimentar. Concomitantemente, diante da crescente preocupação com as questões ambientais, o Plano Setorial de Mitigação e de Adaptação às Mudanças Climáticas para a Consolidação de uma Economia de Baixa Emissão de Carbono na Agricultura - Plano ABC - é uma importante parte do compromisso voluntário assumido pelo Brasil em 2009, na 15ª Conferência das Partes – COP15 ocorrida em Copenhague, na redução da emissão de gases de efeito estufa até 2020. Parte desse compromisso assumido precisa ser atendido pela agricultura familiar, o que aumenta a responsabilidade da mesma para questões que vão além do fornecimento de alimentos, matérias primas e geração de energia etc. O Programa ABC, instrumento pelo qual os agricultores brasileiros podem acessar crédito para implementar tecnologias de baixas emissões de carbono, já está integrado nas ações previstas na Política de Crédito Agropecuário Brasileiro. Porém, ainda se observam vários desafios no Programa ABC, como aumentar o repasse desses recursos, não obstante ao aumento das operações contratadas pelos produtores nos últimos anos. O objetivo do estudo é investigar como a agricultura familiar pode contribuir com o Plano ABC e nos compromissos voluntários assumidos pelo País para a redução de emissão dos gases de efeito estufa no setor agropecuário. Para atingir esse objetivo, realizou-se uma revisão da bibliografia e das linhas de crédito disponíveis pelos bancos públicos e privados relacionadas ao Programa ABC e ao Pronaf. Conclui-se que há sinergias entre algumas linhas de crédito do Pronaf e também do Fundo Constitucional de Financiamento do Nordeste - FNE - Sudene com as tecnologias previstas no Plano ABC. Nesse sentido, o Plano ABC prevê a aplicação de tecnologias de redução de emissões em cerca de 4,97 milhões de ha ocupados pela agricultura familiar, sendo recursos do Pronaf previstos para fomentar tal aplicação, através das linhas Pronaf Eco e Pronaf Floresta. Contudo, verificou-se que tais linhas do Pronaf contemplam o uso de recursos para diversas outras atividades não relacionadas diretamente àquelas previstas no Plano ABC ou capazes de reduzir emissões de gases de efeito estufa. Dessa forma, não há como assegurar que a aplicação de recursos nessas linhas seja direcionada para tecnologias e ações que reduzam emissões, nem tão pouco há como monitorar o volume de recursos do Pronaf aplicados de fato em atividades aderentes ao Plano ABC. Portanto, sugere-se a criação/incorporação de novas linhas de crédito ao Pronaf, como por exemplo, Pronaf ABC Eco e o Pronaf ABC Floresta. Além disso, apresentou-se estudo de caso para o município de Bragança Paulista (SP), onde verificou-se que a utilização dos recursos do Programa ABC poderia ser usada para recomposição de áreas de preservação permanente ou de reserva legal, importantes na preservação das nascentes e rios da região. Essa possibilidade é de elevada importância no contexto e nas discussões atuais sobre a escassez dos recursos hídricos que abastecem grandes cidades, a exemplo do que vem ocorrendo na região metropolitana do Estado de São Paulo. Como conclusão, identifica-se alguns gargalos e apresenta-se algumas sugestões de melhorias para aumentar a utilização e eficácia do Programa ABC, como promover com mais ênfase apoio das assistências técnicas junto aos produtores, priorizar as ações previstas no Plano ABC em algumas regiões do País e aumentar a atuação mais direcionada do Ministério do Desenvolvimento Agrário (MDA) para difusão e incorporação das tecnologias de uma agricultura de baixa emissão de carbono no segmento da agricultura familiar.