Double, double toil and trouble, fire burn and cauldron bubble! Find out what drives a turbine to generate electricity and whether or not it has an impact on the environment. A discussion and lecture is divided by a hands-on activity in which teams turn pinwheels with wind (their own breath) and steam. Presentation slides are included to help explain concepts. This lesson is third in a series of three on how power plants work, but it could easily stand alone.