# 5 Ideas for Experiments on Conserving Energy

1

## Wind Power to Electricity

You might have seen giant wind turbines spinning on hilltops. Well, with this experiment, you can make your own model turbine to try generating electricity from wind.

Start with a 1.5 volt direct current motor. These battery-powered motors are available from hobby shops or online sources. In your experiment, instead of using electricity to turn the motor, you'll be turning the motor shaft with "wind" in order to generate electricity. Mount the motor horizontally on a board with the shaft extending over the edge.

Take a model airplane propeller and fix it to the motor's shaft, perpendicular to the board. Make sure the propeller fits tightly on the shaft or screws down so that when the propeller turns, it turns the shaft. Your "wind turbine" is ready to generate power.

Attach the two wires coming from the motor to a voltmeter that measures up to 5 volts. Between the motor and the voltmeter, connect these two wires using a 100-ohm resistor. You'll need to remove an inch of insulation from each wire and solder the resistor leads (the wires coming from each end of the resistor) to the bare wires. This setup is needed to allow the voltmeter to accurately measure the electricity.

Place the motor and propeller in front of a fan, which will produce the "wind." When the propeller starts spinning, check the voltmeter. It will show you how much electricity is being produced. If you see no movement, or if the voltmeter needle tries to go to the left instead of the right, remove the wires from the voltmeter and reattach them, reversing the sides. See how the voltage changes as the fan speed increases or decreases.

Experiment with different types of propellers. Do larger or smaller propellers affect the amount of electricity produced? Try designing your own propeller. Experiment with multiple blades and blades at different angles. Which produces the most electricity at a given wind speed? Efficient turbines can harness wind energy and conserve energy from other sources [source: National Renewable Energy Laboratory].