Gr 4–6—This terrific series examines the advantages and disadvantages of energy sources, their current uses, and their future viability. Discussion includes descriptions of fuel types, how power plants work, the implications of using different sources for people and the environment, the costs of each system, governments' role in regulating energy, and new and developing technology. Brisk informative texts are enhanced by well-crafted diagrams, eye-catching, captioned photographs, case studies showcasing a global scope, and "Let's Discuss" sidebars that weigh the pros and cons of controversial topics. Each book contains an activity, often science-project inspired, such as how to use a peanut to heat water. Though the absence of a volume on geothermal power is noticeable, this stalwart series is nonetheless an essential purchase.