How Solar Energy Works
A ‘Simple-Language’ Complete Guide to How Solar Panels Turn Sunlight Into Power
Okay.
You’re not a scientist. You may have taken chemistry and physics in high school. Or maybe you didn’t. Either way, let’s be honest — this solar energy stuff is complicated.
Most articles trying to explain how solar energy works end up talking to you at a college level — assuming you know a bunch of science language and concepts that many people actually don’t. And not for lack of trying. One person on our staff used to teach high school chemistry. It’s not easy.
Yes, you’re interested in solar power. But you’re also the type of person who wants to know how things work. It’s not enough to just understand the benefits of solar energy. You want to look under the hood. You want to pull back the curtain and meet the wizard.
This article will attempt to explain in fairly simple language, but it may take you an extra read or two to fully grasp everything. That’s okay! We’re always here to help.
First, do you have kids?
If you have kids somewhere between 4th and 8th grade, ask them to read this article with you.
Tell them it explains how solar power works. If they struggle to understand any part of it — email us and let us know where they got stuck, and we will find a different way to explain it!
Ready? Let’s get to it.
Let there be light
For solar energy to work, it begins with sunlight reaching the earth’s surface.
But light isn’t such a simple thing. What’s it actually made of? How does it produce energy? Did you know people as brilliant as Einstein have puzzled over these questions?
And in fact, it is Einstein’s theory about light that we apply today to make solar power work. But to understand his theory, you first need a basic understanding of atoms.
Atoms? What are atoms?
Atoms are the basic building blocks of everything you see. Whether it’s your couch, your chicken soup, the air, or your fingernails, everything is made of tiny particles called atoms.
How tiny? Smaller than you can see with a microscope. You can see the cells of your body and of plants with a microscope. But cells are also made of atoms, which are several thousand times smaller. They’re so tiny, that billions of them make up the small pieces of your fingernails that you clip off.
There are only about 100 different types of atoms. Stop and think about that for a second. Everything you see, smell, taste, and touch — in the universe — is made up of some combination of 100 different types of atoms. Pretty amazing.
Each type of atom makes a different element, and the elements are found on the periodic table.
Here’s a periodic table. You’ll recognize a lot of these, like oxygen (O), gold (Au), aluminum (Al), and sodium (Na). Others you’ve probably never heard of.
Silicon is highlighted, because for most solar panels used today, silicon is the element that makes it work. There are some newer solar panel technologies that use other elements such as cadmium.
What makes elements unique?
Each element is made of atoms that have different sizes from the other elements. So, oxygen atoms are smaller than sodium atoms, which are smaller than silicon atoms, which are smaller than gold atoms.
The structure and shape of the periodic table is determined in part by the size of the atoms. In general — and this is not totally accurate but we’re keeping it simple — the size increases as you read it left to right and top to bottom. Hydrogen is the smallest.
What makes the sizes different? This depends on the number of protons, neutrons, and electrons — even tinier particles that make up the atoms. The protons and neutrons are in the nucleus in the center. The electrons fly around the nucleus. Thus, most of an atom is actually empty space!
Here’s a basic model you may have seen before:
Electrons: The key to solar power
For solar power to work, the electrons are what make it happen. And that brings us back to Einstein and the question of light. What is light?
Here’s another mind-blowing fact of science:
Light travels in waves, not in straight lines. And even though it doesn’t weigh anything, it still has energy. Energy simply means it can make things happen. When you throw a ball, your arm gives the ball energy. When you turn on a car, the ignition process produces energy in the engine. And that energy in turn makes the car move. Energy makes stuff happen.
And light is also a form of energy. That’s why, when you sit out in the sun for too long, you get hot, and you might get a sunburn. The light energy makes this happen. It has nothing to do with the temperature of the air.
So what does sunlight do to silicon atoms in solar panels?
When light hits any surface, this “solar energy” can cause electrons to escape from their atoms. That means the electron no longer flies around the nucleus, but is free.
Einstein called this the “photoelectric effect.” (We promise, that’s the only big word in this article).
So when sunlight hits the silicon crystals in a solar panel, it releases electrons. Once free, those electrons can travel anywhere within the crystal array. And silicon is uniquely suited for this.
Electric current – The movement of electrons
What is electricity? It’s simply the movement of free electrons. “Current,” a word we see all the time when talking about solar power, is how we measure this movement.
Current: The flow of electrons measured over time. An “ampere,” or amp, measures electrons per second.
The free electrons in the silicon solar panels are now moving, and they have a current. When solar panels are created, the manufacturers insert wires throughout the panels to capture as many of these moving electrons as possible.
Why? Because electrons move more easily through wires than just random surfaces. So the wires allow us to capture more of them to use their current as energy.
Those wires send the current down to the power supply area where it gets turned into solar power. Companies like Ag Solar install solar panels and all the related equipment that enables agricultural businesses, farms, and rural small businesses to generate their own electricity from the sun.
How solar energy works — the basics
Still with us? If you made it this far — you’ve got the basics down.
But how does the electric current from solar panels actually power your farm or rural small business? Read part two: How Solar Energy Makes Electricity.
