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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Life cycle environmental and economic sustainability in the baby food sector

Sieti, Natalia January 2018 (has links)
This research addresses life cycle environmental and economic sustainability in the baby food sector. In the UK, this sector has been growing rapidly, expanding by around 30% between 2009 and 2014, by which time it was worth an estimated £181 million per year. This growth sits within a context of high emissions from the food sector: in 2015, UK net GHG emissions were estimated to be 496 million tonnes (Mt) and the domestic food chain was responsible for 115 Mt CO2 eq. emissions. However, within this overall food chain, very little is known about the sustainability of the baby food sector, with almost no prior literature in the area. The research presented here begins with market research to identify the characteristics of products available in the ready-made food market, in which wet and dry products in jars and pouches dominate sales. Subsequently, 12 representative products are selected from those available on the market and each is assessed in detail to establish its environmental and economic impacts using life cycle assessment (LCA), life cycle costing (LCC) and value added (VA) assessment. The findings of these product-level assessments are then compared to home-made equivalents and finally scaled up according to sales volumes to provide an overall view of the baby food sector as a whole. Wet and dry variants of ready-made porridge products are assessed first as the most commonly consumed breakfast option. The dry product is shown to have 5%-70% the impacts of the wet, on average, and the importance of product formulation is clear: for dry porridge, reformulation could reduce impacts by up to 67%. For the wet porridge, switching from glass jars to plastic pouches is also shown to decrease impacts by up to 89%. Assessment of 11 wet ready-made products demonstrates that the highest impacts are found in spaghetti Bolognese and salmon risotto, and that raw materials are the major hotspot of the life cycle, contributing 12-69%, followed by manufacturing at 2-49%. When combined into a range of weekly diets limited differences are observed between diets, except in cases where dairy-free diets result in compensatory increases in meat consumption. When the aforementioned selection of ready-made products is compared to its home-made equivalent, the home-made options are shown to have lower impacts by 50% to 17 times. This is due to the avoidance of manufacturing and extra packaging stages, as well as shorter supply chains resulting in less waste overall. At the product level, the LCC of ready-made meals ranges from £0.08 to £0.26 per 125 g product, compared to £0.02-£0.20 for the home-made equivalents. Value added is, on average, approximately four times higher for ready-made meals than homemade, illustrating the potential profit of the sector. Annually, the ready-made baby food sector has an LCC of £40m and carbon footprint of 109 kt CO2 eq. This carbon footprint represents only 0.1% of the UK food and drinks sector. The results of this research show that considerable improvements can be made to the environmental and economic sustainability of baby foods, both ready- and homemade, while home-made options tend to have lower costs and environmental impacts. The outputs provide benchmarking and improvement opportunities for industry and government, as well as insight for consumers.
112

Développement de la méthode analyse du cycle de vie territoriale spatialisée (ACVTS) appliquée à l’agriculture. Cas d’étude des bassins versants de la lieue de grève, Bretagne, France. / Development of the spatialized territorial life cycle assessment (STLCA) method applied to agriculture. Case study of the Lieue de Grève catchment, Brittany, France

Nitschelm, Laure 27 October 2016 (has links)
Les travaux de cette thèse se focalisent sur l’élaboration du cadre méthodologique de l’Analyse du cycle de vie territoriale spatialisée (ACVTS), qui intègre la spatialisation dans le calcul des impacts environnementaux, et son application sur un territoire d’étude dans une optique d’aide à la décision. Elle s’organise autour de : (1) la construction du cadre méthodologique de l’ACVTS ; (2) la spatialisation des émissions azotées ; (3) le développement d’une méthode de caractérisation régionalisée de l’eutrophisation ; (4) la comparaison des résultats d’ACVTS et d’ACV. L’ACVTS permet une évaluation des impacts du territoire plus proches des impacts réels et permet de cartographier émissions et impacts pour l’aide à la décision. Gourmande en temps, données et expertise, elle nécessite de bien définir le questionnement de l’étude. / This thesis focuses on development of the spatialized territorial life cycle assessment (STLCA) method, which spatializes environmental-impact calculation, and on its application to a case study to help decision making. The thesis is organized into four main chapters: (1) building the STLCA framework, (2) spatializing nitrogen emissions, (3) developing regionalized characterization factors for eutrophication and (4) comparing STLCA and LCA results. STLCA can estimate environmental impacts of a territory that are more similar to real impacts and can map emissions and impacts to help decision making. However, STLCA requires time, data and expertise to be applied; thus, it is necessary to determine its suitability for the goals of a given study before using it.
113

Considération de la différenciation spatiale dans l'évaluation des impacts environnementaux locaux au moyen de l'Analyse du Cycle de Vie (ACV) : application à la gestion des déchets ménagers / Consideration of spatial differentiation in the assessment of local environmental impacts through the Life Cycle Assessment (LCA) : application to municipal solid waste management

Marchand, Mathilde 09 April 2013 (has links)
La gestion des déchets ménagers concentre des enjeux opérationnels, stratégiques et environnementaux. On observe depuis quelques années une montée en puissance des dispositifs de quantification des impacts environnementaux, qui ajoutent l’espace du calcul environnemental aux espaces déjà constitués et instrumentés des calculs techniques et économiques. Différents outils d’évaluation environnementale peuvent être utilisés tels que l’Empreinte Écologique, le Bilan Carbone ou encore l’Analyse du Cycle de Vie (ACV). Au regard de sa capacité à évaluer des enjeux globaux et multiples, l’ACV est l’outil le plus souvent utilisé. L’ACV évalue les impacts environnementaux potentiels d’un système (produit ou service) en identifiant et en quantifiant les entrants et les sortants de ce système et en les traduisant en impacts environnementaux potentiels. Elle évalue de manière pertinente les impacts globaux, tels que le changement climatique ou la déplétion de la couche d’ozone, mais est peu adaptée à une évaluation des impacts locaux tels que l’acidification, l’eutrophisation ou encore la toxicité du fait de la nécessaire finesse de prise en compte des conditions de l’émission engendrant potentiellement ces impacts. Ce travail de thèse vise à développer une méthodologie d’évaluation « spatialisée » des impacts environnementaux locaux que sont la toxicité (ou atteinte à la santé humaine) et les odeurs et leur intégration à la méthodologie d’ACV. L’intérêt et les limites de ce développement méthodologique sont mis en évidence dans une application de l’évaluation des performances environnementales de systèmes de gestion des déchets municipaux, secteur d’activité soumis à une évaluation environnementale systématique lors de la planification départementale et théâtre de nombreuses controverses dont l’évaluation des impacts locaux est souvent le cœur. La méthodologie d’évaluation développée dans le cadre de cette thèse repose sur l’approche Site Dependent (modélisation de l’impact en considérant les caractéristiques spatio-temporelles de la source d’émission et du milieu impacté) et permet de prendre en compte le devenir de la substance et les conditions d’exposition pour déterminer, dans un premier temps, l’occurrence de l’impact et, dans un deuxième temps, son intensité. Ce développement méthodologique, pour intégrer la différenciation spatiale lors de l’évaluation des impacts, est appliqué à deux impacts locaux reflétant des problématiques locales fortes pour beaucoup de secteurs industriels mais notamment pour le secteur du traitement des déchets : la toxicité et les odeurs. Concernant l’évaluation de la toxicité, il s’agit de caractériser l’impact de manière plus robuste que cela est classiquement fait en ACV en intégrant les caractéristiques spatiales. Pour l’impact odeurs, il s’agit de construire une première voie vers la quantification de cet impact, non évalué par les outils génériques d’évaluation environnementale. / Municipal solid waste management focuses operational, strategic and environmental issues. We observed recently a development of measures to assess environmental impacts, which add the environmental impact to technical and economical calculations. Different environmental assessment tools can be used such as the Ecological Footprint, Carbon Footprint or Life Cycle Assessment (LCA). Due to its ability to assess global and multiple issues, LCA is most often used. LCA assesses potential environmental impacts of a system or a product identifying and quantifying inputs and outputs of the system and converting them into potential environmental impacts. LCA is a relevant method to assess global impacts such as climate change or ozone layer depletion. But this method is not suitable to assess local impacts such as acidification, eutrophication or human toxicity due to the required precision to take into account the conditions of emission that potentially cause the impacts. This PhD work aims to develop a methodology of spatial assessment for two local environmental impacts (human toxicity and odours) and their integration to LCA. Advantages and limitations of this development are highlighted in the assessment of environmental performances of municipal solid waste systems. This sector is subjected to systematic environmental assessment during administrative planning and is prone the numerous controversies in which assessment of local impacts is often the heart of the matter. The methodology developed is based on the Site Dependent approach (modeling of impact with consideration of spatial and temporal characteristics of the emission source and the impacted environmental) and allows to take into account the fate of the substance and the exposure conditions to determine firstly the occurrence of the impact and secondly its intensity. This methodology aiming to integrate spatial differentiation in assessment of impacts, is applied to two local impacts reflecting strong local issues for many sectors, but particularly in the sector of waste treatment: human toxicity and odours. For the human toxicity assessment, the aim is to characterize impacts in more solid way than in conventional LCA that integrates spatial characteristics. For impact odour, the aim is to develop a first approach to quantify this impact, but not assessed by generic tools used for environmental assessment.
114

AvaliaÃÃo de impactos ambientais da produÃÃo de melÃo em sistema convencional e conservacionista no sumÃdio SÃo Francisco / Assessment of environmental impacts of melon production in conventional and conservation system in sumÃdio San Francisco.

Tayane de Lima Santos 20 April 2015 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O SubmÃdio SÃo Francisco à um dos principais polos produtores de melÃo amarelo para o mercado interno brasileiro. Sabendo que as atividades agrÃcolas impactam o meio ambiente, este estudo objetiva avaliar os impactos ambientais, por meio da avaliaÃÃo do ciclo de vida, na produÃÃo de 1 kg de melÃo cultivado no SubmÃdio SÃo Francisco, sob dois sistemas de produÃÃo: convencional e conservacionista. Os dados referentes ao sistema de produÃÃo convencional de melÃo foram obtidos em campo, com entrevistas conduzidas no PerÃmetro Irrigado Salitre (Juazeiro-BA), jà os dados referentes aos sistemas conservacionistas foram obtidos em uma unidade experimental da Embrapa SemiÃrido (Petrolina-PE). Realizou-se uma anÃlise de sensibilidade, considerando quatro cenÃrios: C1 (transporte), C2 (embalagem) e C3 (fertilizantes) e C4 (combinaÃÃo de C1, C2 e C3). O sistema de produto em estudo abrange a produÃÃo de sementes e mudas de melÃo, a produÃÃo agrÃcola dos frutos, a embalagem e transporte do melÃo, e a produÃÃo e transporte dos insumos utilizados nestes processos. Aplicou-se o mÃtodo Recipe na avaliaÃÃo das categorias: MudanÃa ClimÃtica, AcidificaÃÃo do Solo, EutrofizaÃÃo de Ãguas Doces, EutrofizaÃÃo Marinha e Escassez HÃdrica; e o mÃtodo Usetox para avaliaÃÃo da Toxicidade. Os resultados indicaram que, em longo prazo, os sistemas conservacionistas apresentam menores impactos ambientais. Mostraram ainda que as categorias avaliadas sÃo afetadas por trÃs principais processos: transporte dos frutos, embalagem dos frutos e produÃÃo de fertilizantes. Com base na anÃlise de sensibilidade, observa-se que no cenÃrio 4 (que combina a substituiÃÃo das caixas de papelÃo, a utilizaÃÃo de um transporte misto e a supressÃo do uso de fertilizantes nitrogenados) ocorre a maior reduÃÃo dos impactos em todas categorias avaliadas. / The Creative Commons License is a leading producer of yellow melon pole for the Brazilian domestic market. Knowing that agricultural activities impact the environment, this study aims to evaluate the environmental impacts through the evaluation of the life cycle, to produce 1 kg of melon grown in Creative Commons License, under two production systems: conventional and conservation. The data relating to conventional melon production system were obtained in the field, with interviews conducted in the Irrigated Perimeter Salitre (Juazeiro-BA), since the data for the conservation systems were obtained in a experimental unit Embrapa Semi-Arid (Petrolina-PE). We performed a sensitivity analysis considering four scenarios: C1 (transport), C2 (packaging) and C3 (fertilizers) and C4 (combination of C1, C2 and C3). The product system under study covers the production of seeds and melon seedlings, agricultural production of fruits, packaging and transport of melons, and the production and transport of inputs used in these processes. Recipe applied the method in the evaluation of the categories: Climate Change, Soil Acidification, Eutrophication of Freshwater, Marine Eutrophication and Water Scarcity; and the Usetox method to assess toxicity. The results indicated that in the long run, conservationists systems have lower environmental impacts. They are shown even if the evaluated categories are affected by three main processes: transport of fruit, packaging of fruits and fertilizer production. Based on the sensitivity analysis, it is observed that the scenario 4 (combining the replacement of the cartons, the use of a mixed transport and the removal of nitrogen fertilizer use) is the greatest reduction of impacts in all categories evaluated.
115

Seleção de fronteiras para análise de ciclo de vida de sistemas que emitem poluentes tóxicos de chaminés / Boundary selection for LCA of systems with toxic stack emissions

Stelvia Vigolvino Matos 17 September 2002 (has links)
Este trabalho desenvolve um método de seleção de fronteiras para Análise de Ciclo de Vida (ACV) de sistemas que emitem componentes tóxicos. Isto envolve o desenvolvimento de um modelo de predição de concentração e dose de poluentes emitidos de chaminés, que tem a vantagem de ser simples e não requerer grande número de dados de entrada. Esse modelo e mais os dados de valoração econômica de danos ambientais disponíveis na literatura, compõem o modelo geral de estimativa de custos devido à emissão de poluentes, ou seja, a Análise de Custos em Ciclo de Vida (ACCV). O modelo geral é então usado para definir as fronteiras do sistema de ACCV. Demonstra-se a aplicação do novo método em um ciclo de vida hipotético de produção de celulose. / This work develops a method for Boundary Selection (BS) for Life Cycle Assessment (LCA) of systems with stacks emitting toxics compounds. The new approach involves the development of a model of concentrations and dosage of pollutants in the vicinity of emission source that is simple and non-intensive data is required. This model plus impact costs estimations available at environmental economic studies, comprise the general model of Life Cycle Cost Analysis (LCCA) based on exposure. This general model is then used in the Boundary Selection in LCCA. A demonstration of the application of the model is performed to a hypothetical inventory system of a pulp mill.
116

Razvoj sistema za inteligentnu višekriterijumsku procenu opterećenja životne sredine kod ocenjivanja životnog ciklusa proizvoda i procesa / Development of system for intelligent multicriteriaassessment ofenvironmental loading with life cycle assessment of products andprocesses

Agarski Boris 06 March 2015 (has links)
<p>Realizovana istraživanja disertacije mogu se podeliti na tri<br />osnovne celine. Prva celina predstavlja teorijski deo disertacije, u<br />okviru kog su postavljene osnovne podloge za razvoj sistema za<br />inteligentnu vi&scaron;ekriterijumsku analizu kod ocenjivanja životnog<br />ciklusa proizvoda i procesa. Drugu celinu predstavlja razvoj<br />modela i programskog sistema za inteligentnu vi&scaron;ekriterijumsku<br />analizu. U okviru treće celine prikazani su rezultati primene<br />razvijenog modela i programskog re&scaron;enja na primerima<br />ocenjivanja životnog ciklusa i procene opterećenja životne<br />sredine.</p> / <p>Dissertation reserch has been carried out in three main sections.<br />The first section presents the theoretical part of the dissertation,<br />where the base for the development of intelligent multicriteria<br />analysis within life cycle assessment of the products and<br />processes is set up. The second part presents the development of<br />model and software system for intelligent multicriteria<br />analysis.<br />Within the third section the results of applying the developed<br />model and software solution are presented on the case studies of<br />life cycle analysis and assessment of environmental burdens.</p>
117

Avaliação do desempenho ambiental de biodiesel produzido a partir de gordura animal segundo diferentes abordagens para situaçõees de multifuncionalidade. / Assessment of the environmental performance of biodiesel produced from tallow considering different approaches for multifunctionality situations.

Nogueira, Alex Rodrigues 20 December 2017 (has links)
O Brasil é um país que se destaca pela pujança da pecuária e como importante ator no mercado de biodiesel. Entretanto, há uma carência de estudos que investiguem o desempenho ambiental do biodiesel produzido a partir de gordura animal segundo uma lógica sistêmica. Trata-se de um tema controverso em função do tratamento dado à gordura pois, embora haja demanda e mercado bem estabelecido, há casos em que esta substância é tratada como um rejeito da produção de carne, desconsiderando-se os impactos ambientais pregressos. Neste contexto, o presente trabalho foi desenvolvido com o objetivo de avaliar a criticidade de diferentes abordagens para as situações de multifuncionalidade da cadeia de produção do biodiesel obtido de gordura animal. Para tanto, fez-se uso da técnica de Avaliação do Ciclo de Vida de produtos segundo o enfoque atribucional com escopo do \"berço-ao-portão\" para se determinar o desempenho do biodiesel produzido nas regiões Sul, Centro-Oeste e Sudeste, e disponibilizado (tanto puro quanto na forma das misturas B15 e B8) para a região metropolitana de São Paulo entre os anos de 2013 e 2015. As situações de multifuncionalidade foram analisadas a partir da aplicação de critérios físicos (proporção mássica e conteúdo energético), de critérios econômicos e do Método Surplus, além da expansão das fronteiras do sistema e substituição de cargas ambientais evitadas. Os resultados foram expressos em termos das categorias de impacto de Mudanças Climáticas, Acidificação terrestre, Eutrofização aquática, Formação fotoquímica de oxidantes, Demanda de Energia Primária. Adicionalmente, foram feitas considerações a respeito do indicador de Energy Return On Investment (EROI) e do balanço de emissões de gases de efeito estufa. Os resultados indicaram que a alocação das cargas ambientais do processo de refino de petróleo - para a produção do diesel fóssil usado em atividades de transporte - mostrou-se irrelevante no contexto do presente estudo. No que diz respeito ao processo de transesterificação, os efeitos das abordagens para as situações de multifuncionalidade foram pouco influentes sobre os resultados. Isto porque a magnitude do impacto da atividade pecuária foi tamanha que a amplitude dos resultados variou cerca de 817 vezes (no caso da categoria de Mudanças Climáticas) ou até 1084 vezes (para a Demanda de Energia Primária). / Brazil is a country that stands out for the internal importance of cattle farming and as an important player in the biodiesel market. However, there is a lack of studies focusing the investigation of the environmental performance of biodiesel produced from animal tallow according to a systemic scope. This is a controversial issue, due to the treatment given to tallow as, although there is consistent market demand, there are cases in which this substance is treated as a waste from meat production activities. In this context, this study was conducted aiming the evaluation of the criticality of different approaches to multifunctional situations of the biodiesel production chain from animal tallow. In order to do so, attributional Life Cycle Assessment technique was used according to a \"cradle-to-gate\" scope in order to determine the environmental performance of biodiesel produced in the South, Midwest and Southeast regions, and commercialized (either purely or in the form of B15 and B8 mixtures) at São Paulo metropolitan region between 2013 and 2015. Multifunctionality situations were analyzed based on the application of physical criteria (mass ratio and energy content), economic criteria and the Surplus Method, as well as based on system boundaries expansion and the substitution of avoided environmental burdens. The results were expressed in terms of the following impact categories: Climate Change, Terrestrial Acidification, Aquatic Eutrophication, Photochemical Oxidants Formation, and Primary Energy Demand. In addition, considerations were made regarding the Energy Return On Investment (EROI) indicator and the greenhouse gases emission balance. The results indicated that the allocation of environmental burdens at petroleum refining process - for the production of fossil diesel used in transport activities - proved to be irrelevant in the context of the present study. Regarding the transesterification process, the effects of the approaches for multifunctionality situations were not very influential on the results. This is because the magnitude of the impact of cattle raising activity was such that the results varied by about 817 times (in the case of the Climate Change impact category) or up to 1084 times (considering the Primary Energy Demand).
118

Biomass gasification application on power generation: BIGCC systems comparison and other system design

Zang, Guiyan 01 May 2019 (has links)
Biomass is an attractive renewable energy resource for electricity generation, which has the potential to protect air quality, reduce dependence on fossil fuel, and improve forest health. Biomass gasification is a technology that transfers solid or liquid biomass into gaseous energy carrier (syngas) to increase the efficiency of electricity generation. The objective of this thesis is to supply a detailed feasibility study and provide a state-of-the-art economical pathway on biomass gasification application. The work of this dissertation can be separated into two parts: commercial-scale biomass integrated gasification combined cycle (BIGCC) power plants comparison and other biomass gasification system design. The first part compares eight BIGCC systems with three groups of technology variations of gasification agent, syngas combustion method, and CO2 capture and storage. By comparing on performance, economic, and environmental indicators of these systems, it is found that BIGCC systems have higher exergy efficiency and lower emissions than biomass combustion electricity production system and electricity grid. However, its levelized cost of electricity is around 27% higher than the average electricity market price. To reduce the BIGCC system’s cost, in the second part of this thesis, the potential for waste material gasification has been discussed. This part discussed the tire gasification and the gasification technology application for avian influenza poultry management. Results showed that tire gasification has a lower cost than natural gas which has the potential to reduce the BIGCC system’s cost. Moreover, gasification is an effective and economical available approach for avian influenza poultry management.
119

Techno-Economic Feasibility and Life Cycle Assessment of Dairy Effluent to Biofuel via Hydrothermal Liquefaction

Summers, Hailey M. 01 May 2015 (has links)
Uncertainty in the global energy market and negative environmental impacts associated with fossil fuels has led to renewed interest in alternative fuels. The scalability of new technologies and production pathways are critically being evaluated through economic feasibility studies and environmental impact assessments. This work investigated the conversion of agricultural wast, delactosed whey permeate (delac), with yeast fermentation for the generation of biofuel via hydrothermal liquefaction (HTL). The feasibility of the process was demonstrated at laboratory scale with data leveraged to validate systems models used to perform industrial-scale economic and environmental impact analyses. Results showed a minimum fuel selling point of $4.56 per gasoline gallon equivalent (CGE), a net energy ratio (NER), defined as energy required to process biofuel divided by energy in the biofuel produced, of 0.81 and greenhouse gas (GHG) emissions of 30.03 g CO2-eq MJ-1. High Production costs can be attributed to operational temperatures of HTL while the high lipid yields of the yeast counter these heating demands, resulting in a favorable NER. The operating conditions of both fermentation and HTL contributed to the majority of GHG emissions. Further discussion focuses on optimization of the process, on the metrics of TEA and LCA and the evaluation of the process, on the metrics of TEA and LCA, and the evaluation of the process through a sensitivity analysis that highlights areas for directed research to improve commercial feasibility.
120

Selection of Energy Systems in Aquaculture through a Decision Support Tool Considering Economic and Environmental Sustainability

Kim, Youngwoon 30 March 2018 (has links)
Aquaculture had already been distinguished as an important component of global food security and economics. However, aquaculture has expanded at the cost of natural resources and the environment. The vulnerability of the aquaculture industry due to the consequences of global environmental changes and energy price fluctuations has been addressed in various studies. The identification, planning, and implementation of sustainable energy systems are important to ensure the long term economic and environmental sustainability of aquaculture. This research investigated sustainable energy systems for aquaculture using a life cycle approach, allowing for the identification of the most sustainable energy options under different geographical and economic contexts. This also provides useful insights for the sustainable development of aquaculture with energy systems. The main objectives were to develop a statistical model for energy intensity of aquaculture (Chapter 2) and a user-friendly tool that can assist in the decision making of choosing the sustainable energy systems in aquaculture (Chapter 3), and to investigate the applicability of solar hot water systems for aquaculture (Chapter 4) and the potential improvement of the sustainability performance of aquaculture with energy systems (Chapter 5). In the first task, the main influencing factors on the energy use of aquaculture were investigated via a statistical analysis method. Results showed that natural trophic level of species, culture technology, culture system intensity, and local climatic conditions are important factors. With the key variables, an energy intensity prediction model was developed and applied to explore an energy efficient growth strategy for global aquaculture. Energy use in future global aquaculture would be significantly reduced with a selective extensification of global aquaculture. Also, climate change with consideration of temperature and precipitation would help reduce the energy use of global aquaculture as warm climate zones are more dominant in major aquaculture producing countries. In the second task, an MS-Excel based decision support tool was developed to assist the selection of environmentally and economically sustainable energy systems (single source or hybrid sources) in aquaculture. Through a case study, the most sustainable energy options for U.S. aquaponics systems were investigated, considering different geographical and economic contexts in five U.S. states (FL, HI, WA, LA, and ME). Results showed that solar systems (solar photo-voltaic and solar hot water heater) could be the most sustainable energy options for U.S. aquaponics due to their low environmental impacts and economic benefits. In the third task, results showed that heating strategies, setting (indoor or outdoor), and local climatic conditions played a pivotal role in determining the environmental and economic impacts of solar hot water systems in aquaculture. The lowest environmental impact was found with a 20% heating strategy for outdoor aquaculture systems under hot climate conditions, while the most economical case was found with an 80% heating strategy for indoor aquaculture systems under moderate climate conditions. Further improvements of environmental and economic performances could be achieved with consideration of water source (groundwater and surface) and design (horizontally fixed or optimally tilted solar thermal collector). In the fourth task, environmental and economic impacts of alternative energy systems were obtained using the tool which was developed in the second task. Results showed that local geographical and weather characteristics, local energy prices, and incentive availability were important parameters to determine the sustainability performance of alternative energy systems in aquaculture. The use of renewable energy was more sustainable than conventional energy systems in the regions where there are favorable geographical conditions, high electricity and fuel prices, and incentives. The use of solar photovoltaic with a thin-film technology was the most sustainable electricity generation options in most states of the U.S., while the use of natural gas boilers was the most sustainable heating options in most states of the U.S. The sustainability performance of the solar photovoltaic systems can be further improved through either a technological advancement or an incentive, while financial support is more effective for solar hot water systems. The application of anaerobic digestion as a backup system in general will reduce the sustainability of hybrid heating system; however, the hybrid biogas-diesel heating system has better sustainability performance compared with a diesel heating system if it is used for medium to large scale fish farms. This research provides an understanding of energy use characteristics of current aquaculture systems, and insights for the planning of sustainable energy supply systems in aquaculture, considering different growth strategies, effects of climate change, and alternative energy systems with various operational strategies and design factors. Furthermore, the decision-making tool was made to be accessible to fish farmers, state-wide planners, and regulators.

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