How to Make a Solar Cell Car

Hello! This article is written to help students create their very own solar-powered LEGO car from scratch. It will also cover some of the Standards for Technology and Engineering Literacy (STELs, for short) that are incorporated into this process in the hopes of getting 6th-12th grade students interested in technology and engineering. I will be covering the basics of creating a simple solar battery circuit, as well as the process for attaching it to a custom LEGO car that you have built.

To start, I would like to address the STELs that will be incorporated into this article. Firstly, there are the standards of "Core Concepts of Technology and Engineering" and "Integration of Knowledge, Technologies, and Practices". Simply put, this process will help you understand fundamental concepts such as circuits and motors. A well of knowledge should be built on a strong base of fundamentals, and this will give you a good start in the world of technology and engineering. Additionally, you will learn to combine and integrate different technologies (in this case the solar cell, motors, LEGO bricks, and battery) to achieve a desired product.

Second, we have the STEL practices: "Creativity in Technology and Engineering" and "Making and Doing in Technology and Engineering". These are exactly what they sound like. You will be putting to practice your creativity and your ability to "make and do" in the pursuit of your solar-powered LEGO car. The car's design is entirely up to you, and you should exercise your full creative potential

Lastly, there is the STEL context that we are working with: "Energy and Power". This simple solar car will help demonstrate the principles of energy transfer and conversion, using solar energy from the sun to provide DC electrical power to the motors of your car.

The last thing I will say before we get into the meat and potatoes of the process is the objectives. By the end of this article, you will:

• Know how to create a simple battery circuit
• Know how to supply power to a set of motors
• Understand the principle of energy transfer and conversion
• Express yourself creatively by making a LEGO car
• Understand core engineering concepts and be able to integrate different technologies in your process

Various LEGO bricks ($15.99 for a pack of 300)

Four miniature DC motors ($6.99 for a pack of six)

A small solar cell and alligator clips ($6.99)

A rechargeable battery ($10-15)

This will be the most freehand step of the entire process. The way you design your car is entirely up to you! The only restriction is that you will need to leave room for the motors and the battery to fit somewhere. Other than that, you can design it entirely how you want. It can be as simple or as complex as you desire. The pieces in the car above include:

• 4 x medium wheel
• 3 x 6x8 board
• 1 large gear wheel
• 1 1x18 hole bar

Things to Keep in Mind

The battery and the motor(s) are quite large, so you will need to devote a decent amount of space to them. You also do not need to use more than one motor. As shown above, when you attach the motor, it will connect to a rod that grips both of the axles on your car. You can also directly attach the motors to the wheels instead.

The motors themselves are usually only 10mm long and 2 mm wide, but the battery tends to be about 25mm or 1 inch in length. Plan your size accordingly.

Creating the solar circuit is a rather straightforward process. Using the example cell above, you will attach the red alligator clip to the nub on the battery marked with a + symbol. The black clip will connect to the nub marked with a - symbol.

If you've ever heard the phrase "positive to positive, negative to ground", this is exactly that. The red wire carries the electrical current, and the black wire provides an outlet for it. The energy goes into the battery through the red wire, discharges, and then exits via the black wire. This is what makes a circuit.

Take two ends of wire and using electrical tape, secure the exposed copper ends on top of the metal nubs. This is what will carry the energy to the motor(s).

If you're already in high school, you might see a diagram similar to the one above. This is basic solar circuit diagram, and though it might look confusing, this is exactly what you've just created!

This is relatively straightforward. Set the battery and circuit in the space you set aside for it in the car's design. Then take the wire you previously attached, and connect it to the motor's metal hooks or insertion points. Use a small amount of electrical tape to secure the wire, and your solar powered car is complete!

You can choose to leave the solar circuit on the car, or use it exclusively for charging the battery. This is why you taped the wire ends down, so that if you want it to be battery-operated, you can de-clamp the alligator clips and remove the solar cell without any hassle.