Electricity can be generated from different sources, but it is a limited resource. There has been great concern about the growth of energy consumption in the world and the environmental impacts caused by the generation process. Climate change and the greenhouse effect, for example, have prompted several countries to discuss ways of sustainable development. Conceptual content on electricity, the history of the sector in Brazil at different times and in different contexts, population and Gross Domestic Product growth, the relationship between development and consumption in the world, impacts on the environment, prospects and financial data from companies in the sector will be presented here. Interesting questions will be answered, such as: at what growth rates has electricity been consumed in Brazil? Is the growth in energy consumption proportional to the growth in the resident population and economic growth, as measured by the Gross Domestic Product? What is the correlation between them? I look forward to reading it.