If we were to shrink ourselves to the size of small bug, we could better see the small, detailed design that makes up a solar panel. Panels consist of multiple cells called photovoltaic cells. These cells are an integral part of creating energy out of light. So let’s grab our shrinking ray and take a MUCH closer look at a little component called the solar panel photovoltaic cell.
What does photovoltaic cell mean?
The first thing we must understand about the word ‘photovoltaic’ is that it is made up of two parts. The word ‘photo’ means light, whereas the word ‘voltaic’ refers to electricity. So what we have here is a word that means ‘light-electricity’—better explained as, ‘electricity from light’.
It’s the perfect term because that’s exactly what each little photovoltaic cell does; it produces electricity from light. But because one photovoltaic cell is only capable of producing a fraction of the power needed to run a building, MANY of these cells are needed. So how are these cells arranged in a solar panel?
Arrangement of cells in a solar panel
The average home needs a lot more power than a single photovoltaic cell can generate. That’s why solar panels consist of many cells. These cells are arranged in rows. Several rows are then grouped together and a number of groups then form part of the solar panel’s inner section.
Collectively, the stringed-together cells collect loads of sunlight—enough to create an electric current. Most people will purchase at least six panels to enhance the harvesting power of their photovoltaic cell system.
How does a photovoltaic cell work?
But let’s shrink ourselves once more and take a look at how this one little photovoltaic cell works. There are some intricacies involved here, but they can be explained quite simply.
- Special material
An individual cell is made up of two main materials that perform two major functions.
- The first function is that it absorbs light. As you know, certain metallic materials get hotter faster. This is because they absorb heat and light a lot quicker than other materials do.
- The second function is that it is semi-conductive. This means that it relays its energy from one cell to the other—thereby creating a stream of energy.
- Different layers
The cell consists of three layers. The first is the material that absorbs the light. Under that is the semi-conductive material. At the bottom of these two layers is a back plate to hold it all in place.
- Active energy
When light hits the cell, the photons from the sun push the electrons through the second layer. This creates actual energy movement within the cell. But this movement is not random; it follows an ordered flow from one cell to the other, thereby creating a direct current.
Now, times all that activity with the rows, groups and panels of cells in any given system. As you can imagine, this creates a great deal of energy. Once the current is created, it can flow through the DC junction box and finally to the inverter. This inverter converts that current into what we call an alternate current. This is a form of electricity that can be stored in a battery, or used to power a device.
Understanding cell efficiency
There are different kinds of panels and some are made out of different cells to others. Companies who develop these cells are always trying to create ones that are more efficient than those of their competitors. When you hear of solar panel technology taking place, it usually refers to the ongoing development to improve solar cell efficiency.
Cells are made more efficient by maximising the factors that make them work. This includes how light-absorbent they are, how conductive they are, and how many o
f them can fit into a single solar panel. The more efficient a cell, the more power it will ultimately generate for your home or business.
Further efficiency is attained when cells are designed to move with the sunlight. In other words, if a cell follows the direct rays of the sun, it will harvest more light than a cell which remains still. Other developments are sure to take place in the future, so watch this space!
Tiny but awesome
Now that you know what a photovoltaic cell is and how it works, you will better understand the complex process taking place in a solar panel. Remember this process the next time you look at a solar panel and appreciate how intricate it actually is.
* Simple explanation of PV cells on YouTube