Solar Panels: Converting Light into Power

The sun hits a black square on your roof. Your TV turns on. It feels like alchemy. Turning light into lightning. This is the Photoelectric Effect (which Einstein won his Nobel Prize for).

The Silicon Sandwich

A solar cell is made of Silicon (sand).

• Top Layer: Doped with Phosphorus (Extra Electrons).
• Bottom Layer: Doped with Boron (Missing Electrons - “Holes”).
• The Gap: Between them is an electric field.

The Photon Bullet

When a Photon (Light Particle) smashes into the silicon:

1. It knocks an electron loose.
2. The electric field grabs the electron and pushes it into a wire.
3. The flow of electrons = Electricity.

Why No Solar Robots?

If free energy falls from the sky, why do our robots use batteries? Power Density.

• A 1-meter square solar panel improves 200 Watts (in perfect sun).
• An FTC robot motor consumes 300 Watts each. To run a 4-motor robot, you would need a solar panel the size of a car. It’s too heavy. However, for Mars Rovers (which move very slowly), solar is perfect because there are no wall outlets on Mars.