On the adoption of stricter energy efficiency standards for residential air conditioners: Case study Guayaquil, Ecuador.

Space cooling is the fastest-growing energy end-use in buildings worldwide, and Ecuador is no exception. Nevertheless, the last update of the Minimum Energy Performance Standards (MEPS) for air conditioners was in 2013 (EER 3.2W/W); since then, no new standards have been proposed in Ecuador. This study is the first assessment of stricter MEPS and estimation of benefits for the consumers and society of the residential sector in Guayaquil, Ecuador. The life cycle cost, payback time, net present value, electricity savings, and CO2 mitigation are the outputs from the Policy Analysis Modeling System (PAMS) methodology followed. The analysis considers future economic scenarios until 2035. Also, a new engineering approach based on linear optimization defines ACs designs in compliance with the proposed MEPS at the lowest cost. Therefore we can avoid setting less ambitious energy-efficiency targets when efficiency options are limited in the market (this is the Ecuadorian case). The analyzed MEPS are those proposed by UNEP and by the renewal program of inefficient equipment of the Ecuadorian Government. Our estimates show that AC demand can reach 17.3% of the total residential electricity demand in the business-as-usual scenario and 21.4% in the high economic growth scenario until 2035. Furthermore, the results show a significant gap between the proposed MEPS which can be progressively bridged. The best standard from the consumer perspective is EER 4.3W/W, while from the societal perspective, it is EER 5.5W/W. Stricter MEPS can reduce AC electricity demand and energy-related emissions between 5.7% and 31%, depending on the selected scenario. Therefore, stricter MEPS for AC represents a cost-effective option to reduce energy needs and emissions from air conditioners and a concrete action to support the national energy efficiency policies and nationally determined contributions for the residential sector.

Environmental performance of an integrated water supply and wastewater system through life cycle assessment - A Brazilian case study.

The objective of this study was to evaluate the environmental performance of an integrated water supply and wastewater system that employs a system of ponds at the wastewater treatment system. Additionally, this study aimed to understand the contribution of each stage of the system to the analyzed impact categories, and to evaluate alternative scenarios that consider the reduction of water losses in distribution, as well as the operation of an upflow anaerobic sludge blanket (UASB) reactor in the wastewater treatment plant (WWTP). The evaluation was performed through life cycle assessment (LCA) that considered the stages of water withdrawal, treatment, and distribution along with wastewater collection and treatment. The system was modeled in the OpenLCA software using the Ecoinvent 3.7.1 database. Environmental impacts were assessed using the ReCiPe method and cumulative energy demand. The results show that the water withdrawal stage is the potential source of the greatest environmental impacts. There are exceptions in the categories of climate change and photochemical oxidant formation, which are most impacted by the WWTP. Analysis of alternative scenarios revealed that the decrease in water loss rates during distribution contribute to a linear reduction in potential environmental impacts of the analyzed categories. The operation of a UASB reactor in the WWTP leads to a reduction in impacts on the categories of climate change (41.4%) and formation of photochemical oxidants (11.6%), and to increases in impacts on the other categories analyzed. The data presented provide important information for the improvement of public policies aimed at sanitation in developing countries.

Desempenho energético e pegada de carbono de um sistema de esgotamento sanitário centralizado no nordeste brasileiro / Energy performance and carbon footprint of a centralized sewage system in northeastern Brazil

RESUMO O objetivo do trabalho foi avaliar a operação e manutenção de um sistema de esgotamento sanitário centralizado, composto de três subsistemas, que atende 367 mil habitantes no Nordeste do Brasil. A avaliação do ciclo de vida considerou um inventário amplo de operação e manutenção do sistema de esgotamento sanitário com as redes de coleta, estações de tratamento de esgoto, disposição do esgoto tratado no corpo hídrico e gestão do lodo. O arranjo tecnológico das estações de tratamento de esgoto avaliadas incluiu o reator do tipo upflow anaerobic sludge blanket, seguido de lagoa aerada e lagoa de polimento em um subsistema, e upflow anaerobic sludge blanket seguido de reator de lodo ativado por aeração prolongada em dois subsistemas. O desempenho energético utilizou o método de demanda de energia acumulada e a pegada de carbono empregou o método de potencial de aquecimento global de 100 anos do Painel Intergovernamental sobre Mudanças Climáticas. O sistema de esgotamento sanitário avaliado demandou 5,12 MJ·m−3 e emitiu 4,08 kg CO2eq·m−3. As maiores contribuições do sistema de esgotamento sanitário avaliado foram a eletricidade, com 62% da demanda energética, e as emissões diretas para o ar, com 94% da pegada de carbono, sendo as emissões dos reatores upflow anaerobic sludge blanket com 76% da pegada de carbono. A identificação dos aspectos e impactos ambientais do sistema de esgotamento sanitário avaliado apoia a inovação tecnológica e gerencial para otimizar o desempenho energético e mitigar as emissões de gases de efeito estufa.

ABSTRACT This aim of this work was to evaluate the operation and maintenance of a centralized wastewater treatment system, composed of three subsystems, which serves 367 thousand inhabitants in northeastern Brazil. The life cycle assessment considered a comprehensive inventory of the wastewater treatment system operation and maintenance with the collection networks, wastewater treatment plants, disposal of the treated wastewater in the water body and sludge management. The technological arrangement of the evaluated wastewater treatment plants included the Upflow Anaerobic Sludge Blanket reactor, followed by aerated and polishing ponds in one subsystem, and Upflow Anaerobic Sludge Blanket followed by extended aeration activated sludge in two subsystems. The energy performance used the cumulative energy demand method and the carbon footprint used the global warming potential method for 100 years of the Intergovernmental Panel on Climate Change. The evaluated wastewater treatment system presented 5.12 MJ·m−3 and 4.08 kg CO2eq·m−3. The largest contribution of the evaluated wastewater treatment system was the electricity use with 62% of the energy demand and direct emissions to the air with 94% of the carbon footprint, being direct emissions from Upflow Anaerobic Sludge Blanket reactors with 76% of the carbon footprint. The identification of environmental aspects and impacts of the evaluated wastewater treatment system supports technological and management innovations to optimize its energy performance and mitigate greenhouse gases emission.

Are Young Swimmers Short and Middle Distances Energy Cost Sex-Specific?

This study assessed the energy cost in swimming (C) during short and middle distances to analyze the sex-specific responses of C during supramaximal velocity and whether body composition account to the expected differences. Twenty-six swimmers (13 men and 13 women: 16.7 ± 1.9 vs. 15.5 ± 2.8 years old and 70.8 ± 10.6 vs. 55.9 ± 7.0 kg of weight) performed maximal front crawl swimming trials in 50, 100, and 200 m. The oxygen uptake ( V ˙ O2) was analyzed along with the tests (and post-exercise) through a portable gas analyser connected to a respiratory snorkel. Blood samples were collected before and after exercise (at the 1st, 3rd, 5th, and 7th min) to determine blood lactate concentration [La-]. The lean mass of the trunk (LM Trunk ), upper limb (LM UL ), and lower limb (LM LL ) was assessed using dual X-ray energy absorptiometry. Anaerobic energy demand was calculated from the phosphagen and glycolytic components, with the first corresponding to the fast component of the V ˙ O2 bi-exponential recovery phase and the second from the 2.72 ml × kg-1 equivalent for each 1.0 mmol × L-1 [La-] variation above the baseline value. The aerobic demand was obtained from the integral value of the V ˙ O2 vs. swimming time curve. The C was estimated by the rate between total energy releasing (in Joules) and swimming velocity. The sex effect on C for each swimming trial was verified by the two-way ANOVA (Bonferroni post hoc test) and the relationships between LM Trunk , LM UL , and LM LL to C were tested by Pearson coefficient. The C was higher for men than women in 50 (1.8 ± 0.3 vs. 1.3 ± 0.3 kJ × m-1), 100 (1.4 ± 0.1 vs. 1.0 ± 0.2 kJ × m-1), and 200 m (1.0 ± 0.2 vs. 0.8 ± 0.1 kJ × m-1) with p < 0.01 for all comparisons. In addition, C differed between distances for each sex (p < 0.01). The regional LM Trunk (26.5 ± 3.6 vs. 20.1 ± 2.6 kg), LM UL (6.8 ± 1.0 vs. 4.3 ± 0.8 kg), and LM LL (20.4 ± 2.6 vs. 13.6 ± 2.5 kg) for men vs. women were significantly correlated to C in 50 (R 2 adj = 0.73), 100 (R 2 adj = 0.61), and 200 m (R 2 adj = 0.60, p < 0.01). Therefore, the increase in C with distance is higher for men than women and is determined by the lean mass in trunk and upper and lower limbs independent of the differences in body composition between sexes.

Environmental improvement in the printing industry: the case study of self-adhesive labels.

Labels are used for marketing, technical information, local of production and environmental declarations of products. The aim of the study was to evaluate the life cycle of two sets of front and back adhesive labels made with different liners: polyethylene terephthalate (PET) and glassine paper. The study is a pioneering initiative in the labelling industry using life cycle assessment, especially in Brazil. The attributional life cycle assessment method was based on the ISO 14044 standard and covered the entire life cycle, cradle to grave. Primary data for key suppliers, printing facility and label use composed the foreground data, while the ecoinvent database composed the background data. The material efficiency was assessed through mass balance. The impact assessment methods were cumulative energy demand for non-renewable energy and ILCD 2011 midpoint for the environmental categories. The glassine liner is heavier than the PET which resulted in larger environmental indicator values for production, transportation and waste treatment. On the other hand, energy demand of label set with glassine liner was lower than the PET. Furthermore, the hotspot analysis of each impact category was presented per process and substance. The label set made with glassine liner tended to present larger environmental indicator values in most categories, 13 of the 16 assessed, compared to the label set made with PET liner, despite the uncertainties. Contribution analysis identified that the pre-manufacturing step presented larger environmental indicator values than manufacturing, use and post-use steps along the label set life cycle. Therefore, environmental improvement opportunities were evaluated through scenarios of end of life, recycled inputs, domestic suppliers, waste prevention and product redesign. Moreover, the life cycle assessment was useful for diagnosing the energy and environmental profiles of self-adhesive labels and planning cleaner production measures that avoid environmental tradeoffs.

Avaliação energética de um sistema integrado de abastecimento de água / Energy evaluation of an integrated water supply system

RESUMO Os encargos energéticos decorrentes do Sistema Integrado de Abastecimento de Água de Feira de Santana (SIAA-FSA) foram analisados utilizando o método de avaliação do ciclo de vida. Foram identificadas, na cadeia de abastecimento de água, as etapas do sistema com maiores encargos energéticos, e propostos cenários de melhoria. Cadeias de produção dos insumos químicos, transporte dos insumos, energia elétrica e substituição dos tubos na rede para a manutenção do SIAA-FSA foram consideradas. A demanda energética acumulada do SIAA-FSA foi de 3,51 kWh.m-3 de água consumida. As etapas de captação e distribuição de água apresentaram os maiores consumos energéticos, e a eletricidade do bombeamento representou 86% da demanda energética acumulada. Os cenários propostos para o SIAA-FSA apresentaram melhorias significativas em relação ao cenário atual, com usos mais racionais de insumos químicos, eletricidade e água.

ABSTRACT The energy burdens of the Feira de Santana Integrated Water Supply System (SIAA-FSA) were analyzed using the life cycle assessment method. The higher energy burdens in the water supply chain were identified and scenarios for improvement were proposed. The supply chain of chemicals, transportation, electricity and replacement of pipes were considered for SIAA-FSA. The cumulative energy demand of SIAA-FSA was 3.51 kWh.m-3 of consumed water. The water uptake and distribution steps presented the highest energy demands, and the electricity for pumping represented 86% of the cumulative energy demand. The SIAA-FSA proposed scenarios showed significant improvements over the current one, with rational use of chemicals, electricity and water.

Escenario de desarrollo eléctrico en Cuba considerando la opción nuclear / Scenario of electricity development in Cuba including nuclear power

El uso de electricidad en el país ha mantenido un crecimiento sostenido en los últimos años. Con los programas de la revolución energética que se realizan con vistas a elevar el nivel de vida de la población, se espera un crecimiento más acelerado en el uso de la electricidad, aun cuando se introduzca equipamiento más eficiente que el explotado actualmente. En este trabajo se analizó el incremento que tendrá el uso de la electricidad teniendo en cuenta estos programas de desarrollo y la introducción de la energía nuclear como una opción para el suministro de la misma. A partir de las opciones de desarrollo previstas en el tema energía, se estudiaron dos posibles escenarios de cubrimiento de la demanda de electricidad. El primero basa el suministro de electricidad en tecnologías fósiles y el segundo estudia la posibilidad de utilizar en el futuro reactores nucleares modulares de lecho de bolas de nueva generación. Además se incluyeron en el segundo escenario tecnologías renovables y ciclos combinados de gas. Se realizó el análisis de los resultados y se emitieron conclusiones.

The electricity use in the country has maintained a sustained growth in the last years. Due to the programs to enhance the population life being, within the energy revolution program carrying out in the country, a faster growth in the electricity use is expected; even with the introduction of more efficiency equipment. In this paper the increment in the electricity usage taking into account theses programs and the introduction of nuclear power, as an option to meet the electricity demand, were analyzed. Two supply scenarios to meet the electricity demand, which include the energy development options foreseen, were studied. In the first one the electricity supply is based on fossil fuel technologies and the second one the introduction of the new generation of Pebble Bed Modular Reactor is analized. Moreover, in the second scenario, renewable technologies and combined cycles of gas were considered. The results are analyzed, and conclusions were drawn.