Hydroelectricity is energy derived from the power of water in motion. Harnessing energy from water provides clean, available power that does not release harmful chemicals or carbons into the air. This interesting book focuses on the benefits and drawbacks of this energy source and explains how hydro turbines, transformers, and power lines work to bring light to the world. Easy-to-understand conservation tips give readers helpful suggestions on how to conserve electricity and become more environmentally conscious. Teacher's guide available.