Windmill Project For Kids

Wind power has been used for centuries for work, from grinding grain to pumping water on farms. Today, modern wind turbines harness the wind’s energy to generate electricity. In this fun engineering project, kids can build a windmill using basic materials like paper cups and a straw. It’s perfect for learning about renewable energy, simple machines, and engineering design.

DIY Windmill Project

Field of Science: Engineering & Renewable Energy
Grades: 2nd to 5th
🔎 Concepts Explored: Renewable energy, wind power, simple machines, force and motion, and energy conversion.

Wind energy is a form of renewable energy created by air movement. The wind has kinetic energy, or energy of motion, which windmills or wind turbines can capture to perform valuable work. Windmills use this energy to turn blades, which rotate an axle (a simple machine called a wheel and axle) and can power a generator or other mechanism.

This spinning motion generates electricity in actual wind turbines by moving magnets inside a generator. Because wind energy is renewable and does not produce pollution, it is a sustainable power source.

🔎 Look through more mechanical engineering projects here, including a DIY wind turbine project here. For younger students, a pinwheel is a fun alternative.

Supplies:

2 small paper cups (3-ounce size works best)
Bendable straw
Toothpick
Scissors
4 pennies
Tape

How to Make a Windmill

💡 Note: You can use larger cups, but you may need to trim off more of the cup to make it work properly. It’s a great way to experiment and problem solve!

STEP 1: Draw a dot in the center of each cup.

STEP 2: Poke a hole in each cup with toothpick.

STEP 3: Make one hole large enough to place your bendable straw into the cup. It should not flop around.

STEP 4: Tape the 4 pennies inside the cup with the straw, to weigh it down a bit.

STEP 5: Cut slits around the second cup about 1/4 inch apart.

STEP 6: Fold down each strip you cut, to open up your windmill

STEP 7: Place a toothpick inside the windmill cup and then insert the toothpick into the end of the bendable straw.

STEP 8: Blow on, or spin your windmill and watch it go!

FREE Windmill Project Guide!

How Does a Windmill Work?

When wind pushes against the blades of a windmill, it causes them to spin. This spinning transfers energy down the shaft or axle to do work, like pumping water or turning a generator to make electricity. Inside a generator, moving magnets create an electric current in coils of wire. This current can be used to power homes, schools, and more. Windmills are considered eco-friendly because they use a natural resource—the wind—and do not emit greenhouse gases.

Discover how wind power works.
Understand basic renewable energy principles.
Explore the wheel and axle simple machine.
Develop problem-solving and engineering skills.

DIY Windmill STEM Challenge Ideas

Challenge #1: Can you design a windmill that spins faster?
Challenge #2: What happens if you change the size of the cups or blades?
Challenge #3: Can you spin your windmill using outdoor wind instead of blowing on it?
Challenge #4: Add extra blades—does it improve or hinder the windmill’s spin?

Extension Activities

These activities cover renewable energy sources and harness wind power to make them move!

Try a solar oven project to explore other renewable energy sources.
Build a working water wheel to demonstrate renewable energy sources.
Make a wind turbine and compare how it works with your windmill.
Build a DIY wind vane to learn about wind direction.
Create an anemometer to measure wind speed.
Build a wind-powered car and test distances traveled.

STEM Concepts Covered

STEM Resources To Get You Started

Here are a few resources that will help you introduce STEM more effectively to your kiddos or students and feel confident when presenting materials. You’ll find helpful free printables throughout.