Photovoltaic Systems: How They Work
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by: LouieWood | Total views: 21 | Word Count: 687
There are two ways that you can use solar energy, in photovoltaic systems to create electricity or in a solar thermal system for hot water. This article will focus on the generation of solar electricity.
"Photovoltaic": What Does It Mean?
You've probably hear the term "photovoltaic" used a lot, but do you actually know what it means? You probably know that it refers to solar energy. The reason it does is because there are two Latin terms there. "Photo", meaning "light" and "voltaic" meaning electricity. So it's literally light-electricity, which is exactly what is going on here of course, electricity that comes from light.
How Is Light Turned In To Electricity?
Anyone with an inquisitive mind is naturally going to wonder how that is possible. How can anyone turn light in to electricity? When you think about it in that way, it actually sounds like a form of high magic, and in a way you could think about the scientists who came up with it as magicians.
The most important part of this "magic trick" that gets electricity from light is a material known as silicon, which is a semiconductor. Because what happens when light hits a semiconductor is that electrons are released, they are made free within the structure. As electricity is the flow of electrons, that is a crucial first step.
It's only the first step though, you can't expect to just put a semiconductor out in the sun, connect it to a light and expect it to work. Just because the electrons are moving it does not mean that they are flowing, it's not electricity yet.
Solar Cells
It's necessary to set up solar cells in a very specific way in order to create electricity. Put simply, the challenge is to take the electrons that are moving due to the light hitting the semiconductor, and make them flow along a wire to your house.
Imagine you are given this problem as a science experiment. How are you going to go about solving it? Well you're going to have to know a bit about electricity, but for the principles you can use water. How do you get water to flow? One way you can do that is by having it start high up, connect a tube that goes down and watch it flow.
In this case it is gravity which is making the water flow, but in terms of the principles at work, it's about an imbalance. Gravity demands that everything be as low as possible, unless there is some other force stopping it. By raising the water to a higher level then, the imbalance is created, and by connecting a tube you are allowing nature to correct that. So now we just have to create an imbalance in solar cells.
When it comes to solar cells though, the imbalance is not going to be caused by gravity of course, they are not going to react to that. What they will react to, however, is electrical charge because electrons have a negative charge. In a solar cell then, a balance is first created by having a positively charged half right next to a negatively charged half.
As soon as light hits the solar cell, electrons move, and they switch sides. Now there's an imbalance that has to be corrected. It's the equivalent situation of having water in a container off the ground. In this case the tube which is attached is actually a wire that runs to your house. And it is along this wire that the electrons flow.
Using Solar Electricity In Your House
The basic way that photovoltaic systems work has now been summed up. However, there are a couple more issues to contend with. Both can easily be solved though. The first problem is that you are going to want the energy available when you need it, not necessarily exactly when it is produced. This problem is solved by having the electricity charge a battery.
Also, the electricity comes out of the solar panels in the form of direct current. What you need for your house though is alternative current, and the change is made with an inverter. These are the principles by which photovoltaic systems work.
About the Author
Gabriel Wright writes more info regarding solar energy at photovoltaic systems. Find out how much money it's possible to save, and how all of it works. It's also possible to obtain a free installation quote.
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