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In view of the current and predictable energy shortage and environmental concerns, the exploitation of renewable energy sources offers great potential to meet increasing energy demands and to decrease dependence on fossil fuels. However, introducing these sources will be more attractive provided they operate in conjunction with energy storage systems (ESS). Furthermore, effective energy storage management is essential to achieve a balance between power quality, efficiency, costs and environmental constraints. This paper presents a method based on the analytic hierarchy process and fuzzy multi-rules and multi-sets. By exploiting a multiple criteria analysis, the proposed methods evaluate the operation of storage energy systems such as: pumped hydro and compressed air energy storage, H 2 , flywheel, super-capacitors and lithium-ion storage as well as NaS advanced batteries and VRB flow battery. The main objective of the study is to find the most appropriate ESS consistent with a power quality priority. Several parameters are used for the investigation: efficiency, load management, technical maturity, costs, environmental impact and power quality.

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Este artigo apresenta uma metodologia para tomada de decisão multicriterial que visa à seleção de sistemas renováveis de energia considerando as características fundamentais de operação e aplicação destes sistemas. Esta metodologia toma como base o método Analytic Hierarchy Process (AHP) e a lógica fuzzy com intuito de avaliar os principais sistemas de geração distribuída que podem fazer uso de fontes primárias renováveis, tais como: painéis fotovoltaicos, aerogeradores, microturbinas e células de combustível com uso de biogás. Para avaliação destas fontes consideram-se os seguintes critérios: eficiência, custos, maturidade tecnológica, impactos ambientais, amplitude de atuação do sistema e vida útil. Por fim é apresentada uma classificação em ordem de prioridade para o uso das fontes de geração comparando resultados provenientes da aplicação do método AHP e da lógica fuzzy para os cenários custos e meio ambiente.

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Recent advances in power generation technology and new directions in the Brazilian electricity regulation allowed wide spreading of the distributed generation (DG), with some consequent impacts on operational characteristics of the distribution networks. So, new methods for identifying such impacts become necessary in research and development of new tools and resources to maintain and ease the continued expansion towards DG deployment. Initially, this paper presents a study aiming at determination of the appropriate DG locations within distribution systems. This analysis presents a multicriteria analysis to define some qualitative and quantitative parameters using fuzzy logic to determine the appropriate DG sites. In this direction, the paper analyzes transient effects on the feeder power flow from which it is possible to determine the minimal conditions for guaranteeing DG reliability and high power quality. The considerations and results described in this paper make part of the Research & Development Program developed by the State Company for Electric Energy (CEEE) and the Federal University of Santa Maria (UFSM), Brazil.