Book excerpt: Kids will learn valuable hands-on lessons from this guide by constructing working models that generate renewable, alternative energy. Budding scientists learn how to build their own Kelvin water-drop generator out of six recycled cans and alligator-clip jumpers; a solar-powered seesaw from a large dial thermometer and a magnifying glass; and a windmill from eight yardsticks, PVC pipe, cardboard, and a converter generator. Children will investigate the energy-generating properties of a solar cell, a radiometer, a Nitinol heat engine, and a Peltier cell--there are even plans to build a human-powered desk lamp. Each project includes a materials and tools list as well as online information on where to find specialized components.