This is an easy to make wind turbine, which requires only a few spare parts and pieces. You need water bottles, a DC generator and a couple more things. First, cut the bottles horizontally, and melt them together at the tops, then attach them to a pole through the hole of a motor.
It works like this: when the wind blows, the bottles spin, and make the motor on the pole turn, then the motor movement converts mechanical energy to electrical energy. (M->E). then the electrical energy goes to the generator via wires. Finally, the generator powers any devices or loads you hook up.
This relates to engineering because it uses welding to melt the plastic bottles together. you also need to hook up wires to the generator, and put it all together.
Here is the video:
