Estudo técnico relativo à instalação de micro eólicas em edifícios urbanos para microprodução de energia eléctrica

O Planeta Terra tem vindo a ser fustigado pelas alterações climáticas resultado da poluição ambiental provocada pelo Homem. Com o objectivo de minimizar estes efeitos deletérios, os países mais desenvolvidos estabeleceram compromissos relativamente às emissões de gases com efeito de estufa, tendo por base o Protocolo de Kyoto. A iniciativa «Renováveis na Hora» é uma das medidas previstas no plano para a política de energia e alterações climáticas, apresentado em Fevereiro de 2008, pelo Ministério da Economia e da Inovação Português. Actualmente, em Portugal, existe um mercado emergente para a microgeração, que se rege segundo a legislação aplicada recentemente, que estabelece o novo regime jurídico aplicável à produção de energia por intermédio de unidades de microprodução. Esta iniciativa levará à criação de um novo paradigma de exploração e utilização de energia. Deste modo, é fundamental avançar com alguns alertas das condições de exploração. A energia eólica é umas das fontes renováveis em que o rendimento de conversão pode atingir valores interessantes (poderá ser superior a 50%) e em determinadas regiões o seu potencial é bastante bom, nomeadamente em zonas litorais e em zonas montanhosas. Em ambiente urbano é impraticável a instalação de grandes torres eólicas, mas a micro produção baseada em pequenas turbinas eólicas é perfeitamente possível e desejável. O propósito deste trabalho é realizar um estudo de cariz técnico acerca da instalação de um mini parque eólico num edifício urbano, tendo em conta todas as condicionantes (velocidade do vento, obstáculos na zona, altura de montagem, inter-distância entre aerogeradores). Foi realizado um software que irá auxiliar a escolha dos aerogeradores e inversores para o tipo de local onde vai ser instalado o parque eólico.

Genetic algorithm methodology applied to intelligent house control

In recent years the use of several new resources in power systems, such as distributed generation, demand response and more recently electric vehicles, has significantly increased. Power systems aim at lowering operational costs, requiring an adequate energy resources management. In this context, load consumption management plays an important role, being necessary to use optimization strategies to adjust the consumption to the supply profile. These optimization strategies can be integrated in demand response programs. The control of the energy consumption of an intelligent house has the objective of optimizing the load consumption. This paper presents a genetic algorithm approach to manage the consumption of a residential house making use of a SCADA system developed by the authors. Consumption management is done reducing or curtailing loads to keep the power consumption in, or below, a specified energy consumption limit. This limit is determined according to the consumer strategy and taking into account the renewable based micro generation, energy price, supplier solicitations, and consumers’ preferences. The proposed approach is compared with a mixed integer non-linear approach.

SCADA House Intelligent Management for Energy Efficiency Analysis in Domestic Consumers

The implementation of smart homes allows the domestic consumer to be an active player in the context of the Smart Grid (SG). This paper presents an intelligent house management system that is being developed by the authors to manage, in real time, the power consumption, the micro generation system, the charge and discharge of the electric or plug-in hybrid vehicles, and the participation in Demand Response (DR) programs. The paper proposes a method for the energy efficiency analysis of a domestic consumer using the SCADA House Intelligent Management (SHIM) system. The main goal of the present paper is to demonstrate the economic benefits of the implemented method. The case study considers the consumption data of some real cases of Portuguese house consumption over 30 days of June of 2012, the Portuguese real energy price, the implementation of the power limits at different times of the day and the economic benefits analysis.

Eficiência energética e energias renováveis em edifícios

As preocupações com a escassez dos recursos fósseis, o aumento gradual e acentuado dos seus preços e problemas ambientais, cada vez mais há uma preocupação em relação à eficiência energética e as energias renováveis, sendo estes os dois pilares para se encaminhar para uma política energética sustentável. Sobretudo nos edifícios que são responsáveis por grande parte do consumo de energia mundial. Cabo Verde tem um elevado grau de desperdício energético e de consumo de energia elétrica, torna-se imprescindível ressaltar a importância da análise de Eficiência Energética nas Edificações. Contudo, em Cabo Verde, relativamente à vertente da eficiência energética nos edifícios, não existe ainda uma legislação que de alguma forma condicione o consumo de energia e os impactos ambientais associados aos edifícios. De igual forma, as construções com características bioclimáticas ou incorporando sistemas passivos ainda não são prática corrente, pois não existe nenhuma regulamentação que garante que o projetista aquando a conceção de um edifício aplique estratégias de construção bioclimática ou integração das energias renováveis, fazendo o uso do potencial dos recursos renováveis existente no país. Assim, o conforto dos ocupantes dos edifícios e a diminuição das necessidades de consumo não estão presentes de uma forma satisfatória na construção de edifícios em Cabo Verde. Neste contexto, a presente dissertação tem como intuito, recolher e estruturar informação relativa a temática da eficiência energética e energias renováveis nos edifícios de forma a promover a eficiência energética nos edifícios e apoiar o desenvolvimento das energias renováveis em Cabo Verde, contribuindo para a mudança de mentalidade. Assim este estudo pretende refletir sobre a importância da construção sustentável, a Certificação Energética, sistemas e procedimentos para garantir, no mínimo, igual conforto dos ocupantes e simultaneamente a redução do consumo de energia nos edifícios, mudança de comportamentos e escolhas com menor consumo energético. São ainda apresentados as possibilidades de integração das energias renováveis nos edifícios. Assim decidiu-se analisar a implementação de um sistema de microgeração fotovoltaico, para aumentar a eficiência energética de edifícios de acordo com a legislação vigente em Cabo Verde. Nestes termos, é dimensionado um sistema para atender cerca de 70% do consumo anual de energia elétrica do edifício, com consumo de 3869 kWh/ano. Com a realização deste estudo, pretende-se incentivar a implementação de unidades de microprodução fotovoltaica para a produção de energia elétrica em edifícios, bem como aproximar o cidadão comum das soluções técnicas/económicas no campo do aproveitamento das energias renováveis para a produção de energia elétrica.

Multi-agent simulation of continental, regional, and micro electricity markets

Renewable based power generation has significantly increased over the last years. However, this process has evolved separately from electricity markets, leading to an inadequacy of the present market models to cope with huge quantities of renewable energy resources, and to take full advantage of the presently existing and the increasing envisaged renewable based and distributed energy resources. This paper proposes the modelling of electricity markets at several levels (continental, regional and micro), taking into account the specific characteristics of the players and resources involved in each level and ensuring that the proposed models accommodate adequate business models able to support the contribution of all the resources in the system, from the largest to the smaller ones. The proposed market models are integrated in MASCEM (Multi- Agent Simulator of Competitive Electricity Markets), using the multi agent approach advantages for overcoming the current inadequacy and significant limitations of the presently existing electricity market simulators to deal with the complex electricity market models that must be adopted.

Residential energy resources management by a SCADA system in case of excess wind generation

The end consumers in a smart grid context are seen as active players. The distributed generation resources applied in smart home system as a micro and small-scale systems can be wind generation, photovoltaic and combine heat and power facility. The paper addresses the management of domestic consumer resources, i.e. wind generation, solar photovoltaic, combined heat and power, electric vehicle with gridable capability and loads, in a SCADA system with intelligent methodology to support the user decision in real time. The main goal is to obtain the better management of excess wind generation that may arise in consumer’s distributed generation resources. The optimization methodology is performed in a SCADA House Intelligent Management context and the results are analyzed to validate the SCADA system.

Optimal scheduling of a renewable micro-grid in an isolated load area using mixed-integer linear programming

In the energy management of the isolated operation of small power system, the economic scheduling of the generation units is a crucial problem. Applying right timing can maximize the performance of the supply. The optimal operation of a wind turbine, a solar unit, a fuel cell and a storage battery is searched by a mixed-integer linear programming implemented in General Algebraic Modeling Systems (GAMS). A Virtual Power Producer (VPP) can optimal operate the generation units, assured the good functioning of equipment, including the maintenance, operation cost and the generation measurement and control. A central control at system allows a VPP to manage the optimal generation and their load control. The application of methodology to a real case study in Budapest Tech, demonstrates the effectiveness of this method to solve the optimal isolated dispatch of the DC micro-grid renewable energy park. The problem has been converged in 0.09 s and 30 iterations.

Banco de ensaios para micro geração eólica

Mestrado em Engenharia Electrotécnica e de Computadores

Intelligent Micro Grid Management using a Multi-Agent approach

Recent changes in electricity markets (EMs) have been potentiating the globalization of distributed generation. With distributed generation the number of players acting in the EMs and connected to the main grid has grown, increasing the market complexity. Multi-agent simulation arises as an interesting way of analysing players’ behaviour and interactions, namely coalitions of players, as well as their effects on the market. MASCEM was developed to allow studying the market operation of several different players and MASGriP is being developed to allow the simulation of the micro and smart grid concepts in very different scenarios This paper presents a methodology based on artificial intelligence techniques (AI) for the management of a micro grid. The use of fuzzy logic is proposed for the analysis of the agent consumption elasticity, while a case based reasoning, used to predict agents’ reaction to price changes, is an interesting tool for the micro grid operator.

ANN-Based LMP forecasting in a distribution network with large penetration of DG

In recent years, power systems have experienced many changes in their paradigm. The introduction of new players in the management of distributed generation leads to the decentralization of control and decision-making, so that each player is able to play in the market environment. In the new context, it will be very relevant that aggregator players allow midsize, small and micro players to act in a competitive environment. In order to achieve their objectives, virtual power players and single players are required to optimize their energy resource management process. To achieve this, it is essential to have financial resources capable of providing access to appropriate decision support tools. As small players have difficulties in having access to such tools, it is necessary that these players can benefit from alternative methodologies to support their decisions. This paper presents a methodology, based on Artificial Neural Networks (ANN), and intended to support smaller players. In this case the present methodology uses a training set that is created using energy resource scheduling solutions obtained using a mixed-integer linear programming (MIP) approach as the reference optimization methodology. The trained network is used to obtain locational marginal prices in a distribution network. The main goal of the paper is to verify the accuracy of the ANN based approach. Moreover, the use of a single ANN is compared with the use of two or more ANN to forecast the locational marginal price.

A multi-agent based approach for intelligent smart grid management

The spread and globalization of distributed generation (DG) in recent years has should highly influence the changes that occur in Electricity Markets (EMs). DG has brought a large number of new players to take action in the EMs, therefore increasing the complexity of these markets. Simulation based on multi-agent systems appears as a good way of analyzing players’ behavior and interactions, especially in a coalition perspective, and the effects these players have on the markets. MASCEM – Multi-Agent System for Competitive Electricity Markets was created to permit the study of the market operation with several different players and market mechanisms. MASGriP – Multi-Agent Smart Grid Platform is being developed to facilitate the simulation of micro grid (MG) and smart grid (SG) concepts with multiple different scenarios. This paper presents an intelligent management method for MG and SG. The simulation of different methods of control provides an advantage in comparing different possible approaches to respond to market events. Players utilize electric vehicles’ batteries and participate in Demand Response (DR) contracts, taking advantage on the best opportunities brought by the use of all resources, to improve their actions in response to MG and/or SG requests.

Using demand response to deal with unexpected low wind power generation in the context of smart grid

Demand response is assumed an essential resource to fully achieve the smart grids operating benefits, namely in the context of competitive markets. Some advantages of Demand Response (DR) programs and of smart grids can only be achieved through the implementation of Real Time Pricing (RTP). The integration of the expected increasing amounts of distributed energy resources, as well as new players, requires new approaches for the changing operation of power systems. The methodology proposed aims the minimization of the operation costs in a smart grid operated by a virtual power player. It is especially useful when actual and day ahead wind forecast differ significantly. When facing lower wind power generation than expected, RTP is used in order to minimize the impacts of such wind availability change. The proposed model application is here illustrated using the scenario of a special wind availability reduction day in the Portuguese power system (8th February 2012).

Energy and reserve provision dispatch considering distributed generation and demand response

In competitive electricity markets with deep concerns at the efficiency level, demand response programs gain considerable significance. In the same way, distributed generation has gained increasing importance in the operation and planning of power systems. Grid operators and utilities are taking new initiatives, recognizing the value of demand response and of distributed generation for grid reliability and for the enhancement of organized spot market´s efficiency. Grid operators and utilities become able to act in both energy and reserve components of electricity markets. This paper proposes a methodology for a joint dispatch of demand response and distributed generation to provide energy and reserve by a virtual power player that operates a distribution network. The proposed method has been computationally implemented and its application is illustrated in this paper using a 32 bus distribution network with 32 medium voltage consumers.

Distributed generation producers' reserve management

Sustainable development concerns are being addressed with increasing attention, in general, and in the scope of power industry, in particular. The use of distributed generation (DG), mainly based on renewable sources, has been seen as an interesting approach to this problem. However, the increasing of DG in power systems raises some complex technical and economic issues. This paper presents ViProd, a simulation tool that allows modeling and simulating DG operation and participation in electricity markets. This paper mainly focuses on the operation of Virtual Power Producers (VPP) which are producers’ aggregations, being these producers mainly of DG type. The paper presents several reserve management strategies implemented in the scope of ViProd and the results of a case study, based on real data.

Adaptable control for electrical generation at irregural wind speeds

The main aims of this work are the development and the validation of one generic algorithm to provide the optimal control of small power wind generators. That means up to 40 kW and blades with fixed pitch angle. This algorithm allows the development of controllers to fetch the wind generators at the desired operational point in variable operating conditions. The problems posed by the variable wind intensity are solved using the proposed algorithm. This is done with no explicit measure of the wind velocity, and so no special equipment or anemometer is required to compute or measure the wind velocity.