If you look up silicon on a periodic table, you’ll see its atomic number is 14. That means a silicon atom has 14 protons. It usually has 14 electrons, too. They whizz around it like a cloud.
When the sun’s light hits a solar panel, the bits of light, called photons, bang into the silicon atoms. They knock some electrons loose. That leaves empty spots where the electrons used to be.
The solar cell’s electric field pushes the loose electrons up to the top. Then metal parts on the solar cell collect the electrons.
When electrons flow together in one direction, that’s an electric current.
The electric current moves out of the solar panel. It flows into copper wire. Then it travels off the roof and into a machine that changes the type of current from DC to AC. That makes it usable by the outlets in your home.
The electrical current travels through more wire into your breaker box. Then, it’s sent out to your electrical outlets. You use that electricity to power your lights and devices.
Electricity always needs a complete path to flow. That complete path is called a circuit, because the electric current moves through a whole loop.
If it’s super sunny, your solar panel might make more electricity than you can use. Your system might save some in a big battery. It might push some into the shared electrical grid. Your neighbors can use it. The power company tracks how much electricity you shared. Then you can use electricity from the shared grid when you need it, like if it’s a very cloudy day.
When it comes to making electricity, solar panels really shine.
Sincerely,
Dr. Universe
Ask Dr. Universe is a science education project based out of University Marketing & Communications at Washington State University.