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Energy models consider technical and economic criteria to define the optimal energy mix to produce electricity. However, the results are sub-optimal from the social point of view, since they do not include socio-environmental factors. The purpose of this study is to access the sustainability of power plants considering technical-economic, socio-environmental and institutional aspects so that to improve the expansion planning. Thus, the efficiencies calculated by slacks based measure approach of Data Envelopment Analysis methodology can be implemented as constraints in the models, signalizing that the socio-environmental impact cannot exceed a limit, which can be calculated by the energy model itself. The results show that renewable power plants contribute more to allocative efficiency than fossil fuel ones, both in terms of social and environmental aspects, which are of utmost importance in ranking power plants to model power capacity expansion. Considering just technical and economic factors has proved to be insufficient to optimize the system in terms of allocative efficiency.

The energy companies are always facing the challenge of producing more accurate load forecasts. A fuzzy logic methodology is proposed in order to extract rules from the input variables and provide Brazil's long-term annual electricity demand forecasts. In recent literature, the formulation of these types of models has been limited to treating the explanatory variables in the univariate form, or involving only the GDP. This study proposes an extension of this model, starting with population and the GDP additional value. The proposed model is compared with the official projections. The obtained results are quite promising.

In Brazil, the transmission assets are remunerated for their availability regardless of the full utilization of their capacities. The annual allowed revenue for each transmission utility is determined by the Brazilian Electricity Regulatory Agency (ANEEL). ANEEL has been using Data Envelopment Analysis (DEA) to define the regulatory operational expenditure (OPEX) for each utility, a key element for the annual allowed revenue assessment. Based on the ANEEL's DEA model this work proposes improvements in representing the quality of service, transmission capacity and transmission network length in the DEA model. Furthermore, this paper presents a more robust methodology to evaluate the regulatory operational expenditure of transmission utilities by applying several distinct DEA models; then a global efficiency score is defined by the geometric mean of the efficiency scores resulting from the set of DEA models analyzed. The performance of the proposed approach is illustrated with real data of the Brazilian transmission utilities.

This work describes a methodology for long-term electricity demand forecast in the residential sector. The methodology has been used in the power market studies of some Brazilian distribution utilities. The methodology is based on decomposition of the total electricity residential consumption in three components: average consumption per consumer unit, electrification rate and number of households. Then, the forecast for the total electricity consumption in residential sector is the product of forecasts for these three components. The prediction for the number of households is based on demographic models while the future trajectory of the electrification rate is defined by the targets for achieving the universal access to electricity. The product of these two components provides a forecast to the number of residential customers. The average consumption per unit consumer depends on the macroeconomic scenarios for GDP, average household income and income distribution. The proposed methodology provides a framework to integrate macroeconomic scenario, demographic projection and assumptions for ownership and efficiency of electric appliances in a long-term demand forecast. In order to illustrate the application of the proposed methodology, this paper presents a ten-year demand forecasts for the residential sector in Brazil.

No terceiro ciclo de revisão tarifária, a Agência Nacional de Energia Elétrica (Aneel) adotou uma metodologia baseada na Análise Envoltória de Dados (DEA) para a definição dos níveis eficientes dos custos operacionais das distribuidoras. Neste trabalho são apresentadas propostas que aprimoram a metodologia da Aneel. Em particular, propõe-se a segmentação do conjunto de distribuidoras por técnicas de análise de agrupamentos, com a finalidade de estabelecer comparações justas entre as empresas. Adicionalmente, visando obter índices de eficiência que levem em conta as avaliações realizadas pelos pares de cada empresa, propõe-se o uso da avaliação cruzada na definição dos níveis eficientes dos custos operacionais.

The forecasting of electricity consumption and demand plays a pivotal role in electric power systems planning. This paper proposes the combination of forecasts from two approaches with the aim of improving the forecasting accuracy, in order to make the best use of the installed transmission and generating capacity. In the first approach, the consumption time series is decomposed by wavelet analysis and a Box-Jenkins model is fitted to each wavelet component, following which the individual components forecasts are added to compute the total consumption forecast. The alternative approach, uses the Singular Spectrum Analysis technique to model the consumption time series in order to shrink the noise level. Thereafter, the Box-Jenkins model is used to forecast the filtered time series, producing a second forecast for the consumption series. Eventually, the two forecasts are combined geometrically in order to minimize the mean square error. The proposed methodology is illustrated by a computational experiment with the time series of residential consumption of electricity in Brazil.

The non-payment rate has been one of the main problems faced by the electric power distribution utilities. It is therefore essential that the utilities provide a methodology to assess the capability of a residential consumer to pay on time his/her electricity bill. As such, the utility will be able to simulate strategies and mitigate the risk of non-payment. This article presents a proposal based on fuzzy logic approach to compute a “Payment Capability Index” PCI for residential customers. A spatial view of PCI is provided by illustrative maps obtained by Geographic Information System GIS.

The long-term electric power demand forecasting is based on a set of basic premises that includes the macroeconomic scenarios, the growth of the population and of the number of households. The latter is the main determinant to calculate the number of residential customers served by the utilities. This paper presents the headship rate method and its projections for the number of households in Brazil for the years 2010 and 2020. These projections are based on the long term forecasting of the age pyramid of the Brazilian population provided by the Brazilian Institute of Geography and Statistics (IBGE). In order to forecast the number of residential customers in the next ten years, the projections for the number of households are combined with the goals established by the Brazilian Electricity Regulatory Agency (ANEEL) for universalization access to electricity.

Entre os aspectos da qualidade do fornecimento de energia elétrica destaca-se a continuidade, avaliada com base nos indicadores DEC e FEC que expressam, respectivamente, a duração e a freqüência das interrupções do fornecimento. Propõe-se uma nova implementação da regulação por comparação de desempenho na definição dos níveis toleráveis de DEC/FEC (metas de continuidade) para as concessionárias de distribuição e seus conjuntos de unidades consumidoras. Na abordagem proposta combinam-se dois modelos de Análise Envoltória de Dados (DEA) em um processo com dois estágios: primeiro um modelo DEA clássico estabelece quanto cada distribuidora deve melhorar globalmente os seus indicadores de continuidade, em seguida, por meio de um modelo para alocação de recursos, baseado em DEA, comparam-se os desempenhos dos conjuntos em uma mesma distribuidora e definem-se as metas locais de continuidade para cada conjunto. Apresentam-se metas locais para os conjuntos das duas principais concessionárias que atendem o Estado do Rio de Janeiro.The main dimension of the electricity quality is the supply continuity. It is evaluated by indices SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index). This paper presents a new implementation of the yardstick competition that combines two Data Envelopment Analysis models (DEA) to set the continuity standards for the electricity distribution utilities and their groups of consumption units. The approach has two stages. First, a classical DEA model performs a comparative analysis between utilities to define global continuity standards for each utility; next, based on global standards, a model for resource allocation based on DEA establishes the local continuity standards for groups of consumption units in the same utility. Local standards for the consumption units groups of the main distribution utilities in the Rio de Janeiro State are presented.

El Análisis Espectral Singular (AES) es una técnica no paramétrica que permite la descomposición de una serie de tiempo en una componente de señal y otra de ruido. De este modo, AES es una técnica útil para la extracción de la tendencia, la suavización y el filtro una serie de tiempo. En este artículo se investiga el efecto sobre el desempeño los modelos de Holt-Winters y de Box & Jenkins al ser aplicados a una serie de tiempo filtrada por AES. Tres diferentes metodologías son evaluadas con el enfoque de AES: Análisis de Componentes Principales (ACP), análisis de conglomerados y análisis gráfico de vectores singulares. Con el fin de ilustrar y comparar dichas metodologías, en este trabajo también se presentaron los principales resultados de un experimento computacional para el consumo residencial mensual de electricidad en Brasil.