Performance of small wind turbines: simulation of electricity supply to loads connected to the public or isolated grid

Abstract

ABSTRACT:The successful in the implementation of wind turbines depends on several factors, including: the wind resource at the installation site, the equipment used, project acquisition and operational costs. In this paper, the production of electricity from two small wind turbines was compared through simulation using the computer software HOMER -a national model of 6kW and an imported one of 5kW. The wind resources in three different cities were considered: Campinas (SP/BR), Cubatão (São Paulo/BR) and Roscoe (Texas/ USA). A wind power system connected to the grid and a wind isolated system -batteries were evaluated. The results showed that the energy cost ($/kWh) is strongly dependent on the windmill characteristics and local wind resource. Regarding the isolated wind system -batteries, the full supply guarantee to the simulated electrical load is only achieved with a battery bank with many units and high number of wind turbines, due to the intermittency of wind power. KEYWORDS:Homer, wind power, electricity. DESEMPENHO DE AEROGERADORES DE PEQUENO PORTE: SIMULAÇÃO DO FORNECIMENTO DE ENERGIA ELÉTRICA A CARGAS CONECTADAS À REDEPÚBLICA OU ISOLADAS RESUMO: O sucesso na aplicação de aerogeradores depende de vários fatores, dentre os quais: o recurso eólico no local de instalação, os equipamentos utilizados, os custos de aquisição e operacionais do projeto. Neste trabalho, comparou-se a produção de energia elétrica de dois aerogeradores de pequeno porte, sendo um modelo nacional de 6kW e um importado de 5kW, por meio de simulação, utilizando o programa computacional HOMER. O recurso eólico de três cidades diferentes foi considerado: Campinas (SP/BR), Cubatão (SP/BR) e Roscoe (TX/EUA). Um sistema eólico conectado à rede elétrica e um sistema isolado eólico -baterias foram avaliados. Os resultados mostraram que o custo da energia ($/kWh) é fortemente dependente das características do aerogerador e do recurso eólico local. Em relação ao sistema isolado eólico -baterias, a garantia de suprimento integral à carga elétrica simulada só é alcançada com um banco de baterias com muitas unidades e alto número de aerogeradores, devido à intermitência da fonte eólica. PALAVRAS-CHAVE:Homer, energia eólica, energia elétrica.

Perspectives for Implementing Distributed Generation in Developing Countries through Modeling Techniques

“…From a technological point of view, the problems addressed for developing countries present no significant difference compared to the ones generated in developed countries. The reviewed works present significant changes in the operational conditions for improving the efficiency of the equipment, ,,− ,, the optimal coupling of different technologies, ,, and assessing the global energy performance of the system. ,,,,, As most of the research produced in developing countries, the efficiency of the equipment and system is linked to the reduction of costs as well as the greenhouse gas emissions (GHGE) associated with fuel consumption. In the case of renewable sources, this implies an increase in the energy production.…”

“…These conditions are remarkable in old facilities and represent a problem for remote and nonpriority users connected to the grid or during peak consumption hours . The main researches have focused on forecasting or controlling the effects of the interconnection of new technologies to the grid , as well as anticipating the benefits of including new contributors to the energy supply. ,,− The second one is the interaction on the microgrid context. It implies synchronization with different small producers which use DE for interchanging energy utilities.…”

“…Some remarkable issues are the definition of operational policies for synchronizing the energy supply and the demands, especially during peak hours. The main strategies focus on adjusting the operation of the generation technologies ,,, and the use of the storage for reducing gaps. , Off-grid systems are particularly interesting for developing countries where most of the communities lack energy utilities . In the section of social and environmental impact, this condition is addressed again.…”

“…The technologies are dependent on ambient conditions (solar irradiation, wind speed, and water flow). As a consequence, the main objectives addressed for the works are increasing energy generation to ensure meeting the supply, ,,,, using storage technologies, commonly batteries, for reducing the gaps between generation and consumption, ,, and reducing the flicker effect ,,− or interacting with external carriers . The use of biofuels considers the efficiency of generation technologies for reaching a trade-off between the cost of treatment and production of fuel and the environmental benefits and accessibility of resources. − ,, The primary considerations for using fossil fuels, as was mentioned above, are the costs and availability of the resources.…”