Este relatório consolida o esquema de oferta de preços no mercado de curto prazo proposto pela PSR para o sistema brasileiro. Este trabalho foi desenvolvido no contexto do Comitê de Revitalização do Setor Elétrico Brasileiro, durante o anod e 2002.

In competitive hydro-based systems there is a strong incentive for local distribution companies (LDCs) to contract 100% of their load to hedge against the well-known price volatility of the spot markets. Bilateral contracts are usually financial instruments, meaning that the LDCs automatically sell to the spot market any difference between the energy bought through the bilateral contracts and the actual consumption. This means that, if spot prices are high, there will be an incentive for load reduction. This mechanism will allow the potential for load elasticity to be realized. The objective of this work is to analyze this issue, by comparing the tradeoff between giving incentives to customers to reduce their consumption when spot prices are high and the actual benefit of this reduction to the distribution company in terms of revenues. Case studies with data taken from the Brazilian system are presented and discussed.

Most energy sectors are looking carefully at California. An unprecedented electric power deficit has affected one of the main economies of the world, threatening to bankrupt two utilities and having a devastating impact on other economic activities. In Brazil, the government hurries to point out the differences between its situation and that of California. It seems that Brazil has done the opposite of California in many respects and, as a result, faced energy rationing of 20% of the country's load for 7 months in 2001. This article briefly diagnoses what went wrong with the Brazilian reform, contrasts its approach with that of California, and discusses alternatives to improve the situation. In particular, some of the criticisms that have been levied to Brazilian sector reform will be addressed: half of the critics say the solution is more market, the other half that one should go back to state-owned enterprises. In addressing the more-market- side approach, some problems such as bid-based dispatch in cascade hydro plants and the concept of a wholesale water market as well as market power issues are discussed.

For the past two decades, deregulation and restructuring of the electricity sector and creation of competitive electricity markets has been under way in Latin America, where electricity generation is dominated by hydroelectric systems. This article describes how electric sector reform has evolved, what it looks like today, and how hydro is affected.

The objective of this work is to investigate market power issues in bid-based hydrothermal scheduling. Market power is simulated with a Nash-Cournot equilibrium model. In the static model the equilibrium is calculated analytically. It is shown that the total production of N strategic agents is smaller than the least-cost solution by a factor of (N/(N+1)). In the dynamic model (multi-stage, stochastic) the problem was handled through an extended stochastic dynamic programming scheme, where the decision in each stage and state is the Nash equilibrium of a multi-agent game. Case studies with the Brazilian system are presented and discussed.

Hydrothermal systems optimal scheduling requires the representation of uncertainties in future inflows in order to hedge against adverse future low inflows by committing thermal plants, and also to store water in reservoirs while avoiding spillage when high future inflows occur. An inflow scenario tree must be correctly dimensioned so as to provide a parsimonious yet representative sample of possible future inflows to reservoirs. We use a multivariate stochastic inflow model to generate an i.i.d sample of future inflows at each stage, followed by a clustering of similar inflow scenarios to reduce the dimension of the scenario tree. A stochastic scheduling optimization model is applied to different scenario tree sizes and the stability of results is analyzed.

For the past two decades, deregulation and restructuring of the electricity sector and creation of competitive electricity markets has been under way in Latin America, where electricity generation is dominated by hydroelectric systems. This article describes how electric sector reform has evolved, what it looks like today, and how hydro is affected.

In competitive hydro-based systems there is a strong incentive for Distribution Companies to contract 100% of their needs to avoid the well known price volatility of the spot market. Because the bilateral contracts are financial instruments, the load may automatically sells to the spot market any difference between contract and actual consumption. This means that, if spot prices are high, there will be an incentive for load reduction. This mechanism will allow the potential for load elasticity to be realized. The objective of this work is to analyze this issue, by comparing the tradeoff between giving incentives to customers to reduce their consumption when the spot prices are high and the actual benefit of this reduction to the Distribution Company in terms of revenues. Case studies with data taken from the Brazilian system are presented and discussed.

As water demand surpasses water availability, the problem of who will have access to water and who will be rationed is inevitable. This is already the case in arid regions or where the economic uses of water exceed water capability. This work contributes to the understanding and resolution of this decision-marking process. Several cost of water for different users is presented. This model leads to both a water pricing scheme and a method for compensating rationed parties.

Apresenta-se um modelo de otimização inteira mista para expansão da rede de transmissão de um sistema hidrotérmico, no qual se representam as metas de geração hidro no ano de estudo para diversas condições hidrológicas, e também as condições de atendimento das demandas, representadas de forma discretizada em patamares. A formulação disjuntiva do problema aqui adotada evita a não linearidade usual na segunda lei de Kirchoff envolvendo produtos entre variáveis de investimento e de ângulos nodais. A representação detalhada das condições operativas ao longo do ano garante um correto dimensionamento dos reforços de transmissão de sistemas hidrotérmicos. As condições operativas e o despacho são afetadas pelos intercâmbios entre regiões, que podem variar sazonalmente com a condição hidrológica e também com a condição de carga. Um exemplo real ilustra a aplicação do modelo.

Este trabalho apresenta um modelo de otimização para o cálculo da energia firme de um conjunto de usinas, representando de maneira detalhada os aspectos da operação hidrelétrica (balanço hídrico, coeficiente de produção variável com o armazenamento, variação do canal de fuga com a vazão defluente, variação da evaporação com a área do reservatório etc.), além de restrições de transmissão. A aplicação do modelo para o conjunto de usinas hidrelétricas existentes revela que a energia firme dos subsistemas Sudeste e Nordeste é inferior ao respectivo somatório dos certificados de energias asseguradas destas regiões. Isto significa que ocorrerá novo racionamento de energia elétrica caso se repita no futuro a pior situação hidrológica observada no passado. Sugere-se uma revisão metodológica que considere simultaneamente a hipótese de repetição da pior seca do passado e a gradativa diminuição da disponibilidade hídrica para produção de energia elétrica, por conta do uso múltiplo dos recursos hídricos.

Sin resumen disponible.