Avaliação de índices de eficiência e de produtividade de distribuidoras de energia elétrica no Brasil aplicando análise envoltória de dados (DEA)

Abstract

This work investigates the evolution process of technical efficiency indices and Malmquist productivity for the 30 largest power utilities in Brazil, comparing the methodology of the regulator (ANEEL – National Agency of Electric Energy) of evaluation of Regulatory Operational Costs of the Periodic Tariff Review Cycle, with the relationship etween the production technology used by these companies and the quality of services provided to the society between 2003 and 2009, applying the Data Envelopment Analysis (DEA). For this, it is used the following models DEA – input oriented: CRS (CCR), the VRS (BCC) and the NDRS (used by ANEEL), assume that the following technologies returns to scale production: constants, variables, and nondecreasing, respectively. It was adopted two scenarios: the first (called C1), it was observed quantitative variables adopted by ANEEL, taking as input the Operating Cost – OPEX (R$), and as products the Extension of Distribution Networks Electricity - Network (km), the Consumption of Electricity – Market (TWh) and the Unit Number of Electric Consumers – UC (No of Customers), the second (called C2), and quality variables to the scenario C1 are inserted by defining them as products in modeling DEA, the ANEEL’s index of Customer Satisfaction - IASC (NoIndex) and Performance Indicator of Global Continuity – DGC (No Index). Thus, based on performance results relative to the analysis period, it is identified measures of technical efficiency with positive trend and productivity measures with stabilizing trend for the whole of the 30 largest power utilities in Brazil. Furthermore, comparing the results of technical efficiency and productivity in the different scenarios and different DEA modeling (benchmarking), it was found that the implementation of a scenario and a model should reflect the economic reality (closer to the function of real production) of power utilities in Brazil, in order to facilitate the identification of power utilities that are operating at optimal scale (or not) and returns to scale of production are constant , increasing or decreasing. Thus, it was noticed that most companies (C1 equal to 40% and C2 equal to 50%) showed decreasing returns to scale of production (DRS) throughout the time period analyzed. Therefore, the VRS DEA model appears more suitable for the evaluation of performance, rather than modeling the DEA NDRS used by ANEEL, since it allows companies to act in the decreasing region of production frontier and still can be considered efficient. Finally, we discuss the need to improve some points in the methodology used by the regulator, representing challenges to ensuring equity between low tariffs and sustainability of the Brazilian electricity sector, in order to guarantee effectively the economic-financial balance over the next Periodic Tariff Review Cycle.