Metodologia para valoração das externalidades da geração de energia e sua incorporação no índice custo benefício dos leilões de energia

Abstract

Resumo: A expansao da matriz eletrica brasileira nos ultimos anos se deu principalmente por meio de usinas hidreletricas a fio d'agua, usinas eolicas e termeletricas (UTEs) a combustiveis fosseis. Por outro lado, foram poucas as usinas hidreletricas (UHEs) com reservatorios com capacidade de regularizacao, que sao essenciais para garantir a confiabilidade do fornecimento de formas mais economica e ambientalmente sustentavel, contratadas pelo governo. Por 13 anos, de 2000 a 2012, em media 91% da geracao foi de origem hidreletrica, o restante complementado pelas usinas termeletricas e outras fontes. Atualmente, a geracao de origem hidreletrica corresponde a 70% e termeletricas a 17%. As UTEs agora representam 27,45% da capacidade instalada nacional, duas vezes maior do que em 2000. Ocorre que o aumento da geracao por fontes intermitentes (hidrica a fio d'agua, eolica e solar) ocasiona uma necessidade de geracao de base que, caso nao seja atendida por usinas de regularizacao, sera suprida por mais usinas termeletricas. A consequencia e um aumento da emissao de gases de efeito estufa e de material particulado inalavel, alem da elevacao do custo de geracao de energia. Esse maior custo, por sua vez, sera inevitavelmente repassado as tarifas pagas pelo consumidor final, impactando assim a competitividade do pais. Com isso em mente, o objetivo principal desse trabalho e estabelecer criterios, parametros, variaveis e equacoes para valoracao das externalidades atualmente desconsideradas na composicao dos indices custo beneficios (ICBs) de fontes geradoras de energia, visando analisar seus impactos nas negociacoes em leiloes de energia eletrica. Para tanto, o trabalho tece uma analise critica sobre as externalidades da geracao de energia que atualmente nao sao consideradas nas disputas que ocorrem nos leiloes de energia do ambiente de contratacao regulada e desenvolve metodologias para valoracao e incorporacao no ICB dos mencionados certames das seguintes externalidades: o beneficio dos reservatorios de acumulacao das UHEs para o Sistema Interligado Nacional; o beneficio das Pequenas Centrais Hidreletricas (PCHs) para o sistema; o impacto a saude humana ocasionado pela emissao de material particulado inalavel; o impacto da emissao de gases de efeito estufa; e o beneficio da compensacao ambiental. O metodo proposto foi aplicado a um estudo de caso com quatro usinas, que venderam sua energia nos leiloes do governo: uma UHE com capacidade de regularizacao (garantia fisica de 197,7 MWmed.), uma PCH a fio d'agua (garantia fisica de 16,64 MWmed.), uma UTE a gas natural (garantia fisica de 194,1 MWmed.) e uma UTE a oleo diesel (garantia fisica de 121,5 MWmed.). Como resultados, a UHE, a PCH, a UTE a gas natural e a a UTE a oleo diesel tiveram seus ICBs reduzidos em R$ 4,86/MWh, R$ 0,65/MWh e , R$ 0,22/MWh e R$ 0,23/MWh, respectivamente. Assim sendo, identifica-se que o beneficio dos reservatorios de regularizacao e o beneficio das PCHs apresentaram as maiores alteracoes no preco final de energia de cada usina. Palavras-chave: Leiloes de energia. Externalidades. ICB. Hidreletrica. Termeletrica.

Abstract: The expansion of the Brazilian electric matrix in the last few years has occurred mainly by means of run-of-the-river hydroelectric plants, wind and thermoelectric power plants (TPPs) powered by fossil fuels. On the other hand, there were few hydroelectric power plants (HPPs) with reservoirs with regularization capacity, which are essential to guarantee the reliability of supply in more economical and environmentally sustainable ways, contracted by the government. For 13 years, from 2000 to 2012, on average 91% of generation was hydroelectric origin, the remainder complemented by thermoelectric plants and other sources. Currently, hydroelectric generation corresponds to 70% and thermoelectric plants to 17%. The TPPs now represent 27.45% of the national installed capacity, twice higher than in 2000. It happens that the increase in generation by intermittent sources (water, wind and solar water) causes a need for base generation that, if not served by plants regularization, will be supplied by more thermoelectric plants. The consequence is an increase in the emission of greenhouse gases and inhalable particulate matter, in addition to an increase in the cost of energy generation. This higher cost, in turn, will inevitably be passed on to the tariffs paid by the final consumer, thereby impacting the country's competitiveness. With this in mind, the main objective of this work is to establish criteria, parameters, variables and equations for valuing externalities that are currently disregarded in the composition of the cost-benefit indices (ICBs) of energygenerating sources, aiming to analyze their impacts on negotiations in electricity auctions. To this end, the work weaves a critical analysis of the externalities of energy generation that are currently not considered in the disputes that occur in the energy auctions of the regulated contracting environment and develops methodologies for valuing and incorporating in ICB the mentioned events of the following externalities: benefit of the reservoirs of accumulation of the UHEs for the National Interconnected System; the benefit of Small Hydroelectric Plants (SHPs) for the system; the impact on human health caused by the emission of inhalable particulate matter; the impact of greenhouse gas emissions; and the benefit of environmental compensation. The proposed method was applied to a case study with four plants, which sold their energy at government auctions: an HPP with regularization capacity (physical guarantee of 197.7 MW-average), a run-of-river SHP (guarantee 16.64 MW average), a TPP powered by natural gas (physical guarantee of 194.1 MW average) and a TPP powered by diesel oil (physical guarantee of 121.5 MW average). As a result, the HPP, the SHP, the TPP powered by natural gas and the TPP powered by diesel oil had their ICBs reduced by R$ 4.85 / MWh, R $ 0.65 / MWh, R$ 0.22 / MWh and R$ 0.23 / MWh, respectively. Therefore, it is identified that the benefit of the regularization reservoirs and the benefit of the SHP presented the biggest changes in the final energy price of each plant. Keywords: Energy auctions. Externalities. ICB. Hydroelectric. Thermoelectric.