Koontz 
Poop is Power [PDF ebook] 

In Poop is Power, students will learn about the biofuel technology that turns human and animal waste into energy for everything from cooking to powering buildings. Readers will love discovering new information in this chapter book while also reinforcing learned skills with comprehension and extension activities. The Let’s Explore Science series allows readers to dive into the world of fascinating science-related topics while strengthening reading comprehension skills. Each 48-page title features full-color photographs, real-world applications, content vocabulary, and more to effectively engage young learners.