This book is a Primer about energy generation and its use in our industrial society. A majority understand that the energy generation that supports our current way of life also threatens major environmental impact. Though our situation is not imminently apocalyptic, we will have our lives significantly compromised unless we begin to deal with the challenges that our energy generation is causing. With a basic technical understanding of energy, society can make more informed decisions about its generation and use. The book introduces energy. It describes how it's generated, where it's used and considerations for making it sustainable and decarbonized. Today, 80% of energy continues to be from carbon-containing fossil fuels - coal, oil and natural gas . The book sketches how this fossil energy is converted into the work used for electricity, transportation and food. It describes how sustainable energy from sun and wind is more efficient and potentially cheaper. However, sustainable energy is difficult to store, which is a major unresolved problem in the transition from fossil fuels to sustainable energy. The book provides the scientific tools to begin to understand such problems and discusses approaches to make the energy system decarbonized. This book does not tell the reader which options to take, rather it provides the literacy to choose.