The overview of the Brazilian energy sector and the introduction of the free market are presented in the first chapter. The second chapter introduces the concepts of strategic planning principles, among which stand out from the model developed by Porter's five forces, SWOT analysis and cost generic strategies, differentiation and focus to achieve competitive advantages. The third chapter is intended to clarify some concepts of marketing as the broader view of business, market segmentation and positioning, definition of customer value, customer delight and importance of extreme attention to details, customization and personalization, links established, vertical, lateral marketing, and of relationship, epidemic marketing and marketing of the experience. As with the concepts of strategic planning, marketing concepts are illustrated by examples also of the energy area The fourth chapter presents, in table form, various proposals for achieving competitive advantages based on cost, differentiation and on the focus, on different energy sources. These tables show the different marketing tools or management for the differentiation, to the cost or the focus.