Solar light STEM project: how a solar study light works and how to build one safely

Why a solar light STEM project works well

A solar light STEM project is a good fit for a classroom, a club or a small team of friends. The parts are few and inexpensive, the result is something you can hold and use, and every step connects to a real science idea: turning light into electricity, storing energy and using it efficiently.

It also connects to a real problem. About 655 million people lacked electricity in 2024, according to Tracking SDG7: The Energy Progress Report 2026. For a student in one of those homes, a small light can mean more time to read after dark. That gives the project a purpose beyond the grade.

How a small solar light works

The light Flash Forward interns build costs $5.17 in parts and uses six components. Here is what each one does:

• 5V solar panel. Turns sunlight into electricity during the day.
• Charge board. Sits between the panel and the battery and manages charging, so the battery is charged in a controlled way.
• Battery. Stores the energy collected during the day for use later.
• Two LEDs. Turn stored energy back into light. LEDs use little power for the light they give, which is why a small battery can last through an evening.
• Slide switch. Lets the user turn the light on and off, so energy isn't wasted.
• 3D-printed case. Holds everything together and protects the parts.

Put simply, energy moves in two phases. By day: sunlight, then panel, then charge board, then battery. At night: battery, then switch, then LEDs. With about 7 hours of sun, the light reaches a full charge and gives up to about 12 hours of light.

That ratio is worth discussing with your group. Why can a few hours of sunlight power many hours of light? The answer involves how much power the panel collects compared with how little the LEDs use.

A safe, conceptual build walk-through

The easiest way to run this in a classroom or club is with a low-voltage educational solar kit. It comes with its own diagram, so your group can spend its energy on understanding and design instead of guessing at connections. Use adult supervision for soldering, and treat the battery with respect: no puncturing, crushing or heating.

The steps

1. Learn the parts. Lay out each component and have every team member explain its job in one sentence, using the list above.
2. Design the case. Sketch how the parts will fit, where the panel faces the sun and where the light comes out. If you have access to a 3D printer, model and print a case. If not, build a cardboard prototype first.
3. Check the parts. Confirm each part works on its own before you assemble anything. Finding a dead LED now saves an hour of troubleshooting later.
4. Assemble. Connect the parts using the kit's diagram, then fit everything into the case.
5. Charge and test. Leave the light in the sun, then test it in a dark room. Try reading a page of a textbook by it. That's the real test.
6. Record and improve. Write down how long you charged it, how long it stayed lit and what you'd change in version two.

Running it as a club

Split a larger group into small teams of three or four and give each person a role: a builder, a designer who owns the case, a tester who runs the charge and run-time measurements, and a documenter who keeps the build log. Rotate roles on the second build so everyone touches every part.

Two or three sessions is a comfortable pace: one to learn the parts and sketch the case, one to assemble, and one to test, compare results across teams and present what each team would change. Ending with short presentations turns a craft session into real engineering, because teams have to defend their design choices with data.

What you learn

This project covers more than one subject at once:

• Physics. Energy conversion and storage: light to electricity, electricity to chemical energy in the battery, and back to light.
• Engineering design. Making trade-offs between cost, size, durability and brightness, then testing and revising.
• Documentation. Keeping clear notes and measurements so someone else could repeat your build.
• Global awareness. Understanding why a low-cost light matters where there's no electricity at home.

Questions to investigate

• Does the angle of the panel change how well it charges? How could you test that fairly?
• What happens on a cloudy day compared with a sunny one?
• How does the shape or color of the case change how the light spreads across a page?
• If each light costs $5.17 in parts, how many could your class build with a given budget?

Turning one of these questions into a small experiment, with a hypothesis and recorded results, makes a solid science fair entry or passion project.

How Flash Forward interns build lights

Flash Forward Foundation is a student-run 501(c)(3) in Bellevue, WA. Its interns build the same $5.17 solar study light described above, and partner organizations in Haiti, India and DR Congo give the lights to students without electricity. So far, 72 lights have been delivered to partners.

You can see the design on the light page and read about the reasoning in why study lights. Getting lights from a build table to a student involves more than assembly. Someone has to find and work with partners, plan delivery logistics and keep track of it all, which is the work of the Partnerships & Operations track.

Take your project further with a student-run nonprofit

A classroom build teaches you how a solar light works. A student-run nonprofit shows you what it takes to get that light into the hands of a student who needs it. In Flash Forward's Partnerships & Operations track, you work directly with partner organizations, plan delivery logistics and build out the partner-research database, then take on at least two real projects tied to the department's goals. Managers review your work every week, and executives set monthly goals and mentor you.

The internship is fully remote and flexible around school. If this project caught your interest, apply for the internship. The Google Form takes a few minutes and asks for a resume.

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