Windmills are a great way to harness green energy. Unfortunately, they typically require a permanent place to sit. The Trinity Portable Wind Turbine Power Station is different. Designed to fold up and move with you, this family of windmills is usable in breezes of as little as 4 mph, water and weather resistant, have an automatic stop feature, and built-in batteries that let you store the energy you generate. Available in sizes ranging from the highly packable, smartphone-charging 50 to the home-powering 2500.