Solar-powered fan or toy car
A small panel drives a motor for a fan or a car. Good for class competitions.
The big idea
A solar panel connected to a motor turns sunlight directly into movement. Build a car, a fan or both and see whose goes best.
You will need
Tick things off as you gather them.
Step by step
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Step 1: Build the body
Make a flat chassis from card or a plastic bottle. Add two axles with wheels at the front and back. Check that the wheels spin freely.
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Step 2: Add the motor
Fix the motor on the chassis. Connect its shaft to a rear axle using a rubber band as a belt, or press a wheel straight onto the shaft.
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Step 3: Fit the panel
Tape the solar panel on top and wire it to the motor. If the car goes backwards, swap the two wires.
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Step 4: Test it in the Sun
Take the car into full sun and set it down. Watch how fast it moves. Try shade for comparison.
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Step 5: Make a fan
For the fan, fix card blades on the motor shaft in place of the wheels. Connect the panel and hold it in the sun. Feel the airflow.
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Step 6: Race it
Run a race: measure how far each car goes in 30 seconds. Try different panel angles and different wheel sizes.
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Step 7: Improve and retest
Change one thing at a time to make your car faster: lighter body, a bigger belt wheel, a better panel angle. Record the results.
What to look for
- The car speeds up in strong light and slows down in cloud.
- A lighter car goes faster.
- The panel angle changes the speed.
Why it works
The panel turns light into a current, and the current spins the motor. Because there is no battery, the car moves only when the Sun shines on it. Making the car lighter means less force is needed, and a good belt or gear ratio lets the motor turn the wheels at the right speed. Engineers tune these things the same way in solar car races.
Try this next
- Add a second panel in parallel for more current.
- Add a small capacitor and see if the car keeps rolling in a brief shade.
- Hold a class race and compare designs.
Stay safe
Keep fingers clear of spinning fan blades.
Link to the grid
Solar cars and solar plants use the same panels. Engineers get the most from them with careful design, just as grid operators do.
Learn how the grid worksMore sun power experiments
Mini solar panel circuit
A small solar panel lights an LED or spins a toy motor. Test it in sun, in shade and at different angles.
Solar cooker
A cardboard box, foil and plastic wrap trap the Sun's heat. Melt chocolate, warm water or cook rice.
Solar water heater
Black-painted bottles or pipe in the Sun heat water. Measure the temperature as it rises.