Hydropower has been used for hundreds of years in watermills and is now commonly used to generate electricity in applications such as hydroelectric dams and tidal power plants. Explore the power of water by building models and conducting experiments with them. Learn about how different devices are used to extract useful energy from moving water — from a waterwheel in a small stream to a giant turbine in a tidal power station. Build a waterwheel, a sawmill, and a hammer mill to harness the energy of moving water to do different types of physical work.