Gabriel Clemente, PUC-Rio – MSc

The consideration of transmission costs is essential for an isonomic economic valuation of generation projects due to the competition among different sources. The transmission costs tend to be greater for power plants located far from the load centers than for those that are closer. The transmission cost of each agent is calculated through a tariff, whose value depends on the point of connection and might reflect a locational signal of the transmission network’s portion effectively used. The existing methodologies have limitations that greatly hinders the locational signal, therefore, is required a complementary charge known as postage stamp that can be quite significant when compared with the locational portion. The existing methodologies do not consider the multiple dispatch scenarios for allocation of the transmission costs, which is a very important issue and can greatly influence the allocation and create a cost recovery problem, especially in countries with a strong presence of hydroelectric plants. Another important issue to be considered in methodologies for allocation of transmission costs is the calculation of the transmission tariff varying in accordance with the load blocks, whose benefit is enable the consumers to respond to the transmission tariff’s economic signal, increasing economic efficiency. This thesis presents a new methodology based on the AS scheme that incorporates the multiple dispatch scenarios and provides the calculation of the transmission tariff per load block. To illustrate the application of the proposed methodology, it was used a 3-bus test system and the Bolivian power system. The proposed methodology is compared with the following methods: (i) Average Participation Factors (APF); (ii) Long Run Marginal Cost (LRMC) and (iii) Original AS. The results showed that the use of the proposed methodology significantly improved the locational signal, reducing the need of the postage stamp portion of the transmission tariff.

Document only available in Portuguese. For further information, please directly contact the author or email PSR (psr@psr-inc.com).

Ana Carolina Deveza, UFRJ – BSc

Through energy efficiency (EE), the same product or service can be developed using less energy. Thus, it is possible to induce economic development and social welfare through more sustainable use of energy resources. This study aimed to characterize scenarios of electric energy efficiency in Brazil and simulate the effects in the National Interconnected System (SIN) if different EE increase targets are reached on the 2030 horizon. The SDDP computational model was used to simulate four different scenarios of generation expansion: the reference, without increased efficiency and three alternative ones, with energy conservation increase of 10%, 15% and 20%. The results analysis show benefits, such as: reduction in the need for new supply (between 12 and 17 GW average); which causes a reduction of expansion costs (between 24% and 38%) and operation costs (between 42% and 72%); reduction of tariffs for captive consumers (between 16% and 25%); and reduction of national GHG emissions (between 10% and 23%, according to the usual approach, and 10% and 19%, according to the life cycle approach). It can be concluded that the EE increase in Brazil can bring significant economic and environmental benefits for the SIN and its consumers. However, to such benefits become real, the government should enhance the implementation of its plans and programs, coordinating the various economic agents, to overcome the identified barriers and possibly achieve more ambitious conservation goals.

Document only available in Portuguese. For further information, please directly contact the author or email PSR (psr@psr-inc.com).

João Pedro Bastos, UFRJ – BSc

In its sectorial reform in 2002, Brazil introduced a model based on the concept of physical guarantees and contractual certificates to ensure the adequate expansion of the electricity system. The Brazilian model, as it was designed, required the joint contracting of firm energy certificates (a public good associated with the system’s reliability) and the energy itself (whose contracting typically has the function of protecting agents from spot price volatility) - this choice was made in a conscious way, in order to simplify the mechanism and attract new investors. However, the chosen design for the commercialization of energy and firm energy certificates is the root of some inefficiencies in the Brazilian model, such as the lack of liquidity in the contracts’ market, the asymmetry in the participation of free and regulated markets in the system’s expansion, and the overly rigid allocation of risks between generators and consumers. In this study, we propose a mechanism for the separation of the two products, with the aim of contributing to a greater efficiency of the Brazilian energy market. The methodology is based on the capture of the economic value provided by the generators to the system that is not adequately remunerated by the energy market. It was put into practice through a detailed case study of the Brazilian electric system using the SDDP software, calculating the amount of firm energy certificates and its economic value for generators representative of the main technologies present in the system - thermoelectric plants with different variable costs, hydroelectric plants with and without reservoir, wind and solar. Finally, the study concludes with analyzes of the outcomes of a hypothetical firm energy auction, evaluated both on the supply side and on the demand side.

The full study is in Portuguese.

Camila Metello, PUC-Rio – MSc

A penetração crescente de geração de energia renovável combinada com o desenvolvimento de baterias eficazes, capazes de estocar energia no curto prazo, demandam a representação horária (ou até sub horária) de modelos de despacho de operação. A necessidade de representar intervalos de tempo tão curtos implicaria no aumento significativo da dimensão do problema, possivelmente o tornando intratável computacionalmente. Nesta dissertação, é proposto um método capaz de levar em consideração tais pequenos intervalos de tempo, evitando o aumento considerável de esforço computacional para problemas de despacho hidrotérmico. Este método consiste em calcular a representação analítica da função custo imediato que é então aplicada no contexto de programação dinâmica dual estocástica (SDDP). A função representa os custos operativos imediatos em função da decisão ótima de geração hidrelétrica total. Como a função de custo imediato é linear por partes, ela possui estrutura muito semelhante à utilizada para aproximar a função de custo futuro (conjunto de cortes). São apresentados resultados da aplicação do método em sistemas de energia reais.

Rebeca Doctors, PUC-Rio – BSc

Apesar de quase todas as usinas sucroalcooleiras já aproveitarem a queima do bagaço de cana para a produção de energia, muitas ainda não exportam seus excedentes para o Sistema Interligado Nacional (SIN). Tendo em vista o alto potencial da bioeletricidade, capaz de responder por 24% do consumo elétrico brasileiro em 2024 (PDE 2024), esse trabalho de fim de curso busca entender quais os fatores que fazem com que cerca de 16% das usinas cogeradoras vendam energia no Ambiente de Contratação Regulado. Além do mais, é feita uma avaliação macroeconômica do efeito do congelamento do preço da gasolina sobre as usinas sucroalcooleiras e cogeradoras, que em grande parte dependem da sua receita gerada pela venda do etanol. Como principal resultado da análise microeconômica, encontra se uma correlação positiva entre a distância das usinas para subestações e a decisão das usinas comercializarem energia. Mais especificamente, uma usina tem uma probabilidade 5% menor em vender seus excedentes de energia no ambiente regulado quando se dobra a distância até a subestação mais próxima. Na análise macroeconômica foi estudado o balanço financeiro de uma usina base com quatro especificações, o que permitiu avaliar a variação do preço do etanol em quatro casos diferentes. Esse exercício foi feito com a ajuda do OptCana, módulo do OptValue desenvolvido para analisar usinas cogeradoras. Foi encontrado que a política de congelamento do preço da gasolina afetou a TIR média do acionista de uma usina sucroalcooleira em 10 p.p. para baixo, o que acabou prejudicando muitos usineiros e seus projetos de investimento tanto em etanol quanto em vendas de excedente de energia para o SIN.