Solar Weight-Lifter: an Activity That Demonstrates How Solar Panels Work in a Easy to Make, Hands-on Approach

About: Renewable energy education is our mission! REcharge Labs provides curriculum, workshops, and hands-on experiment kits for educators and their students.

Different light sources emit different amounts of radiant energy, but this isn’t always easy to see. Make this visible by creating a solar weight-lifter! This activity converts light energy into mechanical energy in order to lift weight, showing a concrete measurable difference between the light sources. Which light source can lift the most weight?

More in-depth instruction can be found in a free educational guide here.

Step 1: Materials

  • high torque motor (2mm driveshaft)
  • different light sources (incandescent, fluorescent, LED, sun)
  • 3V solar panel*
  • string
  • cup (with two holes drilled around the top, so string can be threaded through)
  • screw hub*
  • weight (washers)
  • duct tape

*these parts can be found (the panel is $12 and the screw hubs are 5 for $5) at the REcharge Labs online store, but another solar panel or a DIY screw hub is also an option!

Step 2: Make the Weight-lifting Device

Tie the string onto the cup and tie the other end onto the screw hub, leaving about a foot of length in between.

Step 3: Add the Solar Panel

Attach the screw hub to the motor. Connect the 3V solar panel to the motor.

Step 4: Attach to a Table

Securely attach the motor to a table with duct tape, allowing the string to hang freely off the side.

Step 5: Test How Much Weight Your Solar-lifter Can Lift

At the first light source, place the solar panel directly facing the light, positioning it 1 cm from the light source. (If using the sun as the light source, distance will not be a factor.) Measure how much weight can be put into the cup, while still allowing the string to lift the cup all the way up to the motor.

Step 6: Continue Testing

Repeat with different light sources. Which light source can list the most weight?

For more ideas, see the free educational plan:



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