Back in my day, hydroelectric power was all the rage. You young whippersnappers and your solar and your wind energy… fie on all that, I say! To demonstrate the majestic simplicity that is hydroelectric power—which, for the record, is in no way simple—to your students, you’ll need to start with the basics. You can’t exactly make water in the classroom, so move on to the next most basic component—the waterwheel. Gather ‘round, kids, there’s science afoot!
Science, Take the Wheel
For this Demo Science science demo, you’ll need disposable plastic plates (like paper plates, but they have to be plastic), a scissor, a pen or pencil, and a source of running water—if your classroom doesn’t have a river running through it, I recommend a faucet. If you really want to get cray, you can have every student make his or her own waterwheel and give them each a turn to test it out (or have them form small groups—they can, like, decorate their waterwheels and $#!t and make it a whole thing).
Step one: use the scissor to cut six to twelve evenly-spaced slits around the outside edge of the plate; note that it has to be an even number of slits or it won’t work. Next, form “blades” on the plate by bending the plate itself at the slits, folding them perpendicular to the face of the plate.
Poke a tiny hole in the middle of the plate, then stick your pen or pencil through and work it around a bit until it can move in and out easily. Then, turn on the faucet and get yourself a fairly fast stream o’ water going. Hold one end of the pencil and maneuver your makeshift waterwheel into the stream so that the flow of agua catches the blades on the wheel.
If everything goes according to plan (if we can call that ^^^ a plan), your waterwheel should start spinning. The water will push the first blade down, which brings the next blade into the stream, where it gets push down by the water, bringing the next blade into the stream, etc. etc. ad infinitum.
Wheel of Electricity
The materials and construction may be rudimentary, but your classroom waterwheel works on the same scientific principles that a legit hydroelectric waterwheel uses to generate power. Large-scale hydroelectric plants are built near dams or swift rivers so that large quantities of rapidly moving water can turn these massive wheels and generate the maximum amount of electricity.