Learn about the scientists, engineers, and other people working to bring us new energy options.Calling All Innovators series introduces students to careers in science and technology. The complex text allows readers (Grades 5-8) to determine the main idea and explain how it is supported by key details. For decades, people around the world have relied mainly on the burning of fossil fuels to power machines and create electricity. However, as scientists uncover the destruction these fuels are doing to the environment, alternative energy sources such as wind, solar, and geothermal power are becoming more common.