ABSTRACT
RESUMO A busca por energias alternativas que sejam renováveis está cada vez maior, assim como a preocupação com o crescente aumento da geração de resíduos pela população mundial. O aproveitamento energético do gás gerado pela decomposição dos resíduos sólidos é um caminho atrativo para a solução, de uma só vez, desses dois problemas. Com objetivo de contribuir para o desenvolvimento da geração de energia elétrica a partir de aterros sanitários no Brasil, o presente trabalho compreende uma análise de potencial energético e de viabilidade financeira dessa alternativa energética no Brasil. Para a construção das análises, utilizaram-se dados de geração de resíduos e climáticos de seis cidades brasileiras, o que permitiu a estimativa da vazão de produção de gás nos aterros de cada uma dessas localidades, a potência ótima a ser instalada em cada um desses aterros e da viabilidade econômica dessa alternativa. Os valores de custo de geração obtidos variaram entre R$ 345 e 440·MWh, sendo fortemente influenciados por fatores como população, captação de resíduos e aspectos climáticos, sendo, em geral, superiores aos valores típicos de tarifa de venda de energia no país. Isso implica uma necessidade de formulação de políticas públicas de incentivo à geração de energia a partir de resíduos sólidos urbanos no Brasil.
ABSTRACT The search for alternative and renewable sources of energies is growing, as is the concern with the growing increase in the generation of waste by the world population. The energy use of the gas generated by the decomposition of solid waste at landfills is an attractive way to solve these two problems, at once. In order to contribute to the development of electric power generation from landfills in Brazil, the present work comprises an analysis of the energy potential and financial viability of this energy alternative in the country. For the construction of the analyses, waste and climate generation data from six Brazilian cities were used, which allowed the estimation of the gas production flow in the landfills of each city, the optimum power to be installed in each of these landfills and the economic viability of this alternative. The generation cost values obtained ranged between R$ 345 and 440·MWh, being strongly influenced by factors such as population, waste capitation and climatic factors, being, in general, higher than the typical values of energy sales tariff in the country. This implies a need to formulate public policies to encourage the generation of energy from solid urban waste in Brazil.
ABSTRACT
Climate change, population growth, migration, urbanisation, and ageing infrastructure will all impose significant strains on the urban water services in Europe, and cities across Europe will experience increasingly frequent shortfalls in supply/demand balance. It is widely accepted that the mitigation of these and other emerging challenges should be sensitive to increasing energy prices, the environment, and the desire for low carbon intensity solutions. This paper presents the development of a new methodology for assessing the impact of household water savings from different water demand management interventions based on their water-related energy use and cost, as well as their impact on the supply/demand balance. The methodology has been applied to the water distribution system of a European city to demonstrate its application using different water demand management interventions for different types of water savings. Sensitivity analysis for different population growth rates that are representative of the different growth rates across the EU was carried out. The results show different degrees of water, energy, and cost savings can be achieved depending on the type (s) and proportion of household micro-component appliances and fittings considered. In all the intervention strategies considered, there are important trade-offs to be made between the different performance indicators as not all interventions will result in water savings and/or reductions in water-related energy use and costs or have a positive impact on supply/demand balance.