The present work presents an analysis of the impacts of using distribution-level locational marginal prices (DLMPs) as a basis for valuing distributed generation (DG) connected to the low-voltage grid. In order to do so, we study the consistency of the economic signaling characteristic of the DLMPs and the impacts that DG may have on the operation of the low voltage electrical system, using a case study, in which distributed generator agents connected to a 13, 8 KV feeder system are affected by using DLMPs as a basis to value their energy production. The simulations carried out in the case study consider a large number of operating scenarios in an attempt to capture the effect of the variations in energy demand and availability of the primary energy source of DG that in cases of sources such as solar and wind are very intermittent. In addition, this work introduces a Linear Programming (LP) formulation for the optimal dispatch problem in alternating current systems, considering as objective function the optimal generation dispatch and incorporating linearization strategies, especially developed for analysis of low-voltage grids, in which is considered, a large number of operating scenarios with participation of intermittent generation.

The present work presents a methodology based on market equilibrium to predict future electricity prices in the environment of free market for contracts with duration of one and three years. In this approach, generators offer their contracting levels according to market prices (contracting supply curve) and the loads, in turn, stipulate their contracting levels for each market price (contracting demand curve), in the meeting point of the curves the equilibrium price is obtained in the contract market. The methodology is based on bi-level optimization with equilibrium constraints where scenarios represent the uncertainty of short-term market prices. The risk measure for generators and loads is a weighted average of expected value and the expected value within a confidence interval (known as Conditonal Value at Risk), of revenue and expenditure, reflecting their degrees of risk aversion.

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

The paper evaluates the impact of Brazilian Nationally Determined Contribution (NDC) to the power sector in the context of the Paris Agreement during the twenty-first session of the Conference of the Parties (COP) of December 2015. It investigates the adequateness of specific targets of the NDC by comparing additional power supply costs with mitigated greenhouse emissions. The study evaluates power system expansion and operation for the 2030 horizon considering a “business as usual” scenario (no targets to the power sector) and a “COP21 Scenario” with targets for energy efficiency and the share of non-hydro renewable electricity production.

The Paraiba do Sul river basin (PSRB) plays a central role in Brazil. Over 180 municipalities in the states of São Paulo, Rio de Janeiro and Minas Gerais depend on its waters, through the operation of multipurpose reservoirs in the main stem and tributaries. The PSRB faced a severe drought in 2014. This event motivated discussions on reservoir operating rules, such as reservoir draft prioritization and reductions of minimum flow requirements that were ultimately established by the national water authority (ANA) in coordination with the national power system operator (ONS). New operative rules enacted by ANA Resolution 1382/2015 prioritize water supply over hydropower. It counteracted the concept that hydropower was responsible for reservoir overdraft, risking water supply of cities such as Rio de Janeiro. However, there is scarce technical justification to validate the new rules, much less to assess their impacts in multiple uses of water. The objective of this paper is to compare alternatives of PSRB operating schemes through a simulation approach. Three scenarios were investigated: (i) Reference Scenario, that considers the operation of the river basin prior to the 2014 water crisis, (ii) New Resolution Scenario, which evaluates the operation after the water crisis and considers the new rules set to prioritize water supply reliability; and finally (iii) an Alternative Scenario, based on guide-curve reservoir operation introduced in this article. A long period of inflow measurements - over 86 years - provides a consistent resource to perform this evaluation. The integrated, basin-wide simulations were made with the Water Evaluation and Planning (WEAP) model of the Stockholm Environment Institute (SEI), a friendly and opened framework for future research.

Keywords: Integrated Water Resource Management, Reservoir operating rules, Paraiba do Sul River Basin, WEAP model.

The main objective of the Generation Expansion Plan (GEP) is to ensure an adequate balance between electricity supply and demand, i.e., to determine the optimal set of generation projects that must be built to meet the demand along a horizon (medium and long term). The expansion plan optimization process means minimizing a cost function by taking into account: (i) investment (capital) and operating costs (fuel, operation and maintenance, etc.) of generation plants and (ii) penalties related to energy not supplied, also called deficit costs. In summary, in this paper the generation expansion planning task is carried out through a computational tool that determines the minimum cost expansion plan for an electrical system, encompassing hydroelectric, thermal and renewable candidate projects and is integrated with a dispatch simulation tool that represents in detail the production of all plants in the system. The minimum cost GEP is achieved by optimizing the trade-off between the investment costs for the construction of new projects and the expected value of the operating costs obtained from the stochastic hydrothermal dispatch model, allowing a detailed representation of the system operation under uncertainty. In conclusion, this paper aims to show (i) a description of the Electricity System of the Dominican Republic, (ii) the methodology used to determine the generation expansion plan, and (iii) a scenario-based analysis. The expansion plans will be compared through: (i) the technologies involved, (ii) the environmental impact and (iii) the operational and economic performance.

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