Alexandre Beluco

PV hydro hybrid systems

The energy systems based on renewable resources face several acceptance difficulties mainly due to high initial costs and to low final incomes. A way to improve the effectiveness of these systems is the use of more than a source of energy, mainly when the employed sources present some type of complementarity. An interesting combination is obtained with the use of hydro and solar energy resources, that it allows to take advantage of the complementarity among two sources and it allows to investigate the storage of energy in water reservoirs and in batteries. The configurations with a bus in cc would assist demands of until 1 kW to 2 kW, while configurations involving a bus in ca evidently would reach larger powers. This article discusses PV hydro hybrid systems, characterizing some configurations, discussing operation strategies, commenting on the effects of the complementarity in time among the energy sources and evaluating that complementarity in the State of Rio Grande do Sul, in the south of Brazil, besides presenting preliminary estimates of costs.

Modeling pumped hydro storage with the micropower optimization model (HOMER)

Most renewable energy technologies suffer from an intermittent characteristic due to the diurnal and seasonal patterns of the natural resources needed for power generation; therefore, a complementary energy storage system must be considered. The pumped hydropower plant is a suitable alternative to consider as an energy storage device for hybrid systems. The hybrid optimization model for electric renewables (HOMER) optimization model is widely used around the globe for designing, comparing, or evaluating the performance of hybrid power systems, but it does not include an explicit component to model a pumped hydropower facility. This paper describes a method for representing a pumped hydropower plant by creating an equivalent battery in HOMER, and the procedure was accompanied by a detailed example. An additional example of a wind-hydro hybrid power system with controlled parameters is presented to validate the method. The results support that the procedure explained in this paper adequately represents the pumped hydropower plant as an equivalent battery.

Energetic Complementarity with Hydropower and the Possibility of Storage in Batteries and Water Reservoirs

The complementarity of energy resources used in hybrid systems can open new perspectives for the design of energy systems. Complementarity may be important as a tool for decision makers can sort projects and may be important for an energy system can overcome periods of energy scarcity. This chapter proposes a way to assess the complementarity of energy resources with a dimensionless index and study the effect of different degrees of complementarity on the performance of PV hydro hybrid systems. This chapter also presents some case studies, discussing consequences of complementarity in real systems.

Consequences of Reducing the Cost of PV Modules on a PV Wind Diesel Hybrid System with Limited Sizing Components

The use of renewable resources for power supply in family homes has passed the stage of utopia to became a reality, with limits set by technical and economic parameters. This paper presents the results of a project originated from the initiative of a middle-class family to achieve energy independence at home. The starting point was the concept of home with “zero energy” in which the total energy available is equal to the energy consumed. The solution devised to meet the energy demand of the residence in question is a PV wind diesel hybrid system connected to the grid, with the possibility of energy storage in batteries and in the form of heating water and the environment of the house. As a restriction, the family requested that the system would represent little impact to the lifestyle and landscape. This paper aims to assess the consequences of reductions in the cost of the PV modules on the optimization space, as conceived by the software Homer. The results show that for this system, a 50% reduction in the cost of PV modules allows all viable solutions including PV modules.

On the wave energy potential along the southern coast of Brazil

The ocean wave energy resource is a real alternative to supply part of the energy demand in various countries, since some locations have a remarkable capacity to generate electricity. The objective of this study is to evaluate the energy resource of ocean waves in the coast of Rio Grande do Sul, the southern state of Brazil. This note presents the first results. The wave data used were collected in the sea area near the Port of Rio Grande during the years 1996 to 1999, amounting to sixteen months of monitoring. The data set was treated and grouped resulting information monthly, seasonal and annual basis. The annual average was found to be 8.6 kW per meter of wave front, reaching 14.0 kW per meter for the month of May and 4.0 kW per meter for the month of January. The results indicate good perspectives in obtaining power supplies. Copyright

Classification of textures in satellite image with Gabor filters and a multi layer perceptron with back propagation algorithm obtaining high accuracy

The classification of images, in many cases, is applied to identify an alphanumeric string, a facial expression or any other characteristic. In the case of satellite images is necessary to classify all the pixels of the image. This article describes a supervised classification method for remote sensing images that integrates the importance of attributes in selecting features with the efficiency of artificial neural networks in the classification process, resulting in high accuracy for real images. The method consists of a texture segmentation based on Gabor filtering followed by an image classification itself with an application of a multi layer artificial neural network with a back propagation algorithm. The method was first applied to a synthetic image, like training, and then applied to a satellite image. Some results of experiments are presented in detail and discussed. The application of the method to the synthetic image resulted in the identification of 89.05% of the pixels of the image, while applying to the satellite image resulted in the identification of 85.15% of the pixels. The result for the satellite image can be considered a result of high accuracy. Copyright

Complementarity in Time between Wind and Water Resources in Northeastern Brazil

The world is in a time when the energy resources have been under increasing pressure from a growing demand with higher quality requirements. At the same time, our world, largely based on non-renewables, see these resources approaching scarcity. In this context, it is important to get energy supplies from renewable resources and seek ways to leverage these resources as well as possible. The complementarity between energy resources can be a way to make better use of available resources, enabling a greater supply of energy and facilitating the management of devices for energy storage. This paper presents preliminary results of the identification of complementarity between water and wind resources in a portion of northeastern Brazil. The effects of complementarity for the benefit of the feasibility of a wind hydro hybrid system will prove more effective in conditions of scarce energy resources, contributing to the reduction of the cost per kWh of supplied energy. The map provided in this article can indicate areas where investments in wind hydro hybrid systems will lead to energy supplies with lower specific costs. The map of complementarity indicates that about 40% of the studied area has high levels of complementarity in time.

Simulating an ocean wave power plant with Homer

In recent years, renewable resources have become an important alternative to increase the capacity of power generation. Among the resources available, the energy in the oceans have attracted more interest and experiencing a period of strong development. Wave energy is the one that is currently closest to reach a stage of technical and economic maturity. In this process, computational tools to facilitate evaluation of the feasibility of power systems including ocean wave power plants are critical. This paper presents the use of software Homer, version Legacy, for evaluation of technical and economic feasibility of hybrid energy systems including contribution of wave energy. Homer is a software designed for the optimization of micro power systems that has a very broad spectrum of applications. A case study in southern Brazil is presented, studying the inclusion of an ocean wave power plant in a wind biodiesel hybrid system and showing the functionality of Homer for this purpose. Copyright

Preliminary determination of the energy potential of ocean currents along the southern coast of Brazil

The ocean can be a strategic alternative for obtaining energy supplies, both from ocean waves as from sea currents and tides. Among these features, the power generation projects based on ocean currents are still under development. Generating energy from ocean can have great impact on the Brazilian energy grid, since Brazil has a vast coastline, with more than 9,000 km long, with potential for generating energy from ocean currents not fully estimated. This article presents a preliminary determination of the energy potential for power generation from ocean currents along the coast of Rio Grande do Sul, the southernmost state of Brazil, and also presents notes that contribute to the characterization of the system of ocean currents in the region. The data used were obtained in two areas near Tramandaí, allowing the determination of velocities and directions of the currents on a seasonal basis. The maximum speeds obtained rarely exceed 0.750 m/s, while the average speeds do not exceed 0.200 m/s. A relationship with the prevailing winds in the region was identified. Unfortunately, the results do not allow optimism about the power generation from ocean currents on the southern coast of Brazil, at least over the continental shelf. Copyright

Modelling a hydropower plant with reservoir with the micropower optimisation model (HOMER)

Hydropower with water accumulation is an interesting option to consider in hybrid systems, because it helps dealing with the intermittence characteristics of renewable energy resources. The software HOMER (version Legacy) is extensively used in research works related to these systems, but it does not include a specific option for modelling hydro with reservoir. This paper describes a method for modelling a hydropower plant with reservoir with HOMER by adapting an existing procedure used for modelling pumped storage. An example with two scenarios in southern Brazil is presented for illustrating and validating the method explained in this paper. The results validate the method by showing a direct correspondence between an equivalent battery and the reservoir. The refill of the reservoir, its power output as a function of the flow rate and installed hydropower capacity are effectively simulated, indicating an adequate representation of a hydropower plant with reservoir is possible with HOMER.