How Does Solar Energy Work
No doubt, solar energy is one of the best -if not the best- source of energy we can use to power our homes.
It’s clean, efficient, and most importantly, it can save you tons of money each month.
But have you ever wondered how do solar panels work?
Like how can these black or dark blue boards generate electricity?
Well, if you are looking for a super geeky, yet easy-to-understand answer that will make you look smarter at family gatherings, then this article is specially made for you.
In this guide, we will show you exactly how do solar panels work starting from sunlight hitting the panel to how it’s converted to electricity to power your devices.
However, in order to understand how do solar panels work. First, we need to know what is the main component of solar cells.
So without further ado, let’s jump right into what are solar cells made off.
What are solar cells made of?
The answer is silicon AKA sand, and that’s it, now the next section would be… Just kidding.
While solar panels are actually made of silicon, sprinkling some sand on your roof won’t generate any electricity at all.
That’s because sand alone is useless, and to make solar panels, silicon must be purified and treated in a way to allow it to absorb sunlight and convert it into electricity.
So why do scientists choose sand in particular to make solar panels?
Well, sand is great for manufacturing solar panels for two reasons:
First, silicon makes 27.7% of the earth’s crust. In other words, it’s super cheap and can be easily found almost anywhere.
The second reason to go for sand is that it’s a very good semiconductor.
Semiconductors such as Silicon and Germanium are known for their relatively stable state.
For instance, each Silicon atom has only four electrons in the conductive level, having a half-full conductive level means that the atom is marginally stable, and losing or gaining electrons will make the atom less stable.
In simple terms, under ideal conditions, the Silicon atom will act exactly like inactive materials.
However, because we don’t live in an ideal world, external forces such as temperature, pressure, and light can provide weak electrons with enough energy to break free from the nucleus’s magnetic force and disrupting this inactive state.
Each electron break free from the silicon wafer leaves behind a hole.
As we all know, atoms really love to be stable and in order to achieve that and make up for the lost electron(s), the atoms become positively charged and each atom tries as best as it can attract an electron to reach the stable state.
This ladies and gentlemen results in a flow of electrons AKA electricity.
But what does this have to do with how solar panels work?
Well, that’s exactly what we will answer in the next section.
How do solar cells work?
Solar cells working concept is the photovoltaic effect, which is simply how light can knock electrons out of their atomic orbits.
To understand how light can knock out electrons, first, you need to know that light isn’t just a wave. In fact, light is made of very small particles called photons.
When a photon hits an orbiting electron, the electron absorbs some of the photon’s energy and if this absorbed energy is big enough, the electron will break free from the nucleus magnetic force, resulting in a free electron.
For simplicity’s sake, think of the photon as a tennis ball and the electron as a bottle of water on a fence.
If the photon hit the electron with enough power (you through the tennis ball), the electron will break free from the nucleus force (the bottle will fall off the fence)
Now, what would happen if multiple photons hit multiple electrons with enough force?
Correct, we will have a big flow of electrons (current) that we can use to power our appliances and charge our batteries.
And that’s exactly how solar cells work.
How much energy does a solar panel produce?
The amount of energy produced by a solar panel is determined by three factors:
- The number of solar cells in each panel
To make a solar panel, you need to solder together a number of solar cells via metal connectors (busbars) to form a matrix-like structure.
In general, most solar panels are made by connecting 48, 60, or 72 solar cells together, dispending on your power and panel size needs.
- The light conversion efficiency and dimensions of each solar cell
Not all solar cells are made equally.
In fact, solar cells come in many different efficiencies ranging from 6% and all the way to 50%. However, most commercial solar panels will have around 15-30% efficiency.
Obviously, the higher the solar cell efficiency, the more power it produces, so making a solar panel by connecting more efficient solar cells will only lead to high power solar panels.
Another thing to keep in mind is the dimensions of the solar cell, as the bigger the cell is, the larger the light-receiving area and the more power it will produce.
- The number of sun hours the solar panel gets
Finally, the last factor that determines the solar panel output is how many hours of sunlight does the panel get.
Naturally, if you placed a solar panel in a sunny spot for 8 hours, it would produce much more energy than leaving it for just 10 minutes, as this will allow more photons to hit the solar cells and create more electricity.
It’s important to mentions that there are many other factors that can affect the amount of energy the solar panel produces such as the sunbeam intensity, solar panel mounting angle, azimuth, temperature, humidity, and many more.
However, these factors can be pretty hard to measure and you need special equipment to do this besides that their effect is very minimal compared to the three main factors.
In general, how much energy is produced by a solar panel is calculated using this simple formula:
Energy Produced = Solar Panel’s Wattage * Number Of Peak Sunlight hours
For instance, if you live in a sunny place like Perth city where you get an average of 5.3 hours of sunlight, then a 300 watt solar panel will produce around 1590 watts/day (300 watts * 5.3 hours), which is enough energy to power a small off grid cabin or a boat.
As promised, in this article we showed you exactly how do solar panels work in as much detail as possible.
In the end, we really hope you enjoyed this article as much as we did.
Do you have any questions about solar cells?
If so, please share your thoughts with us in the comments section below.