Efficiency Curves for Hydroelectric Generating Units

Hidalgo, Ieda Geriberto; Fontane, Darrell G.; Lopes, João E. G.; Andrade, José Geraldo Pena de; Angelis, André Franceschi de

doi:10.1061/(asce)wr.1943-5452.0000258

Cited by 14 publications

(3 citation statements)

References 7 publications

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“…Over the years there has been an increase in sedimentation, reduction of the original efficiency of the turbines and changes in evaporation. Regular studies have been developed to update flow data [72,73] and evaporation data [74].…”

Section: Outdated Operational Information To Plan the Electricity Sectormentioning

confidence: 99%

A review of the causes, impacts and solutions for electricity supply crises in Brazil

Hunt

Stilpen

Freitas

2018

Renewable and Sustainable Energy Reviews

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From the end of 2013 to the end of 2015, Brazil faced serious challenges to supply its demand for electricity due to a prolonged drought in the Southeast and Northeast regions with the consequent loss of hydroelectric generation. This paper presents an historical analysis of major world energy crises from 1988 to 2015 and in Brazil from 1924 to 2015. Analysing the natural river flow of key Brazilian dams from 1931 until 2017, this paper suggests that hydropower generation in Brazil has a 10 to 15 years cyclical pattern of hydropower generation. The periods of drought in this cyclical pattern usually coincides with energy crises due to the reduction in hydropower generation. It was found that the drought in 2015 had an impact of 110 TWh in hydropower generation, from which 25 TWh are due to head loss and 70 TWh are from lack of stored hydropower in July of 2014. In addition, 48 TWh were not generated due to delays in the construction of new power plants. Other causes of the Brazilian energy crisis of 2015 are presented and the overall electricity generation impact of these causes are compared. In addition, this paper presents the impacts on the energy, water and food supply sectors in Brazil, and the strategies employed to reduce the impact of the crises. With the intention of preventing future energy crises, the paper then shows the potential alternatives to improve electricity supply security in Brazil, particularly in terms of diversifying and widening the share of renewable sources and increasing the energy storage potential of the country.

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Section: Outdated Operational Information To Plan the Electricity Sectormentioning

confidence: 99%

A review of the causes, impacts and solutions for electricity supply crises in Brazil

Hunt

Stilpen

Freitas

2018

Renewable and Sustainable Energy Reviews

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“…Two equations are important for the ODD of the GUs: the hydraulic balance and production function, Hidalgo et al [1]. The hydraulic balance determines the reservoir's final volume from the initial volume, water inflow, and water outflow.…”

Section: Introductionmentioning

confidence: 99%

Metaheuristic Approaches for Hydropower System Scheduling

Hidalgo

Barros

Fernandes

et al. 2015

Journal of Applied Mathematics

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This paper deals with the short-term scheduling problem of hydropower systems. The objective is to meet the daily energy demand in an economic and safe way. The individuality of the generating units and the nonlinearity of their efficiency curves are taken into account. The mathematical model is formulated as a dynamic, mixed integer, nonlinear, nonconvex, combinatorial, and multiobjective optimization problem. We propose two solution methods using metaheuristic approaches. They combine Genetic Algorithm with Strength Pareto Evolutionary Algorithm and Ant Colony Optimization. Both approaches are divided into two phases. In the first one, to maximize the plant’s net generation, the problem is solved for each hour of the day (static dispatch). In the second phase, to minimize the units’ switching on-off, the day is considered as a whole (dynamic dispatch). The proposed methodology is applied to two Brazilian hydroelectric plants, in cascade, that belong to the national interconnected system. The nondominated solutions from both approaches are presented. All of them meet demand respecting the physical, electrical, and hydraulic constraints.

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“…It is characteristically dynamic, uncertain, and nonlinear. However, it is important to have accurate estimates of the variables involved in hydroelectric planning so that software, used for optimization and simulation of the system, provide reliable results (Lopes 2007;Hidalgo et al 2010Hidalgo et al , 2013ONS 2014).…”

Section: Introductionmentioning

confidence: 99%

Management of inflow forecasting studies

Hidalgo

Barbosa

Francato

et al. 2015

Water Practice and Technology

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In hydroelectric systems, water inflow is important to coordinate a cascade and define the energy price. This paper presents a method for managing inflow forecasting studies with a specific module for advanced assessment. The main goal is to provide a structure that facilitates the analysis of water inflow prediction models. A case study has been applied to five mathematical models based on linear regression, artificial neural networks, and hydrologic simulation. These models present daily and monthly inflow forecasts for a set of hydroelectric plants and monitoring stations. The benefits of the proposed method are analyzed in four situations: water inflow prediction, performance evaluation of a specific model, research tool for inflow forecasting, and comparison tool for distinct models. The results show that implementation of the proposed method provides a useful tool for managing inflow forecasting studies and analyzing models. Therefore, it can assist researchers and engineering professionals alike by improving the quality of water inflow predictions.

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Efficiency Curves for Hydroelectric Generating Units

Cited by 14 publications

References 7 publications

A review of the causes, impacts and solutions for electricity supply crises in Brazil

A review of the causes, impacts and solutions for electricity supply crises in Brazil

Metaheuristic Approaches for Hydropower System Scheduling

Management of inflow forecasting studies

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