Beginners Guide To Solar Power

February 7, 2012 by Liam Raikes  
Filed under Science

The function of a solar cell is very simple. It takes light, and it makes it into electricity. It’s very simple, but that doesn’t mean it is easy. Imagine if you were tasked to create something that could actually do that, most people wouldn’t know where to start. Well, by the end of this article, you’re not going to be an expert in how to build solar panels, but you should at least understand the principles involved.

How Does Light Become Electricity?

To answer this question of how it is that light becomes electricity, we have to be more clear about exactly what light is and what electricity is. There isn’t room to go into detail about this of course, but we can get a general idea.

A Photon

The most important thing to know about light when it comes to solar panels is that it can be viewed in two ways, as being made up of waves and as being made up of particles. In fact both is true, which is a bit strange, but this is something that has come out of quantum physics.

In terms of solar cells, the most useful way to think about light is as being made up of particles of light. That is what a photon is, it is the name for a particle of light. If you’re wondering how light can be thought of as being particle based, in terms of waves it is the smallest packet of waves that you can get (if that makes it any clearer!).

What Is Electricity?

Electricity consists of the uniform flow of electrons in a substance. The substance has to have certain qualities which allows this to happen, they have to be made up in a particular way. When the conditions are right, then we call that material conductive, because it can conduct electricity. This applies to metals mostly.

There is another type of material though which conducts electricity in a slightly different way. It still has to do with the electrons flowing, but this flow can be created by the existence of “holes” in which there should be an electron. This hole will attract an electron, so that is how electricity can flow as well. Substances that do this are called semiconductors.

Solar Cells

With this information, the way that a solar panel actually works can be described more easily. The first thing to know is that they are made of a semi-conductive substance, often silicone. The important thing about this is that when a photon hits the semiconductor which the cell is made of, it pushes an electron out of its orbit and this creates a “hole” in it, like the ones described above. This is what causes electricity to flow.

It’s not quite as simple as getting a semiconductor and hooking it up to some wires though. There are actually two halves, one of which has to be negatively charged and the other half has to be positively charged. In their normal state, these halves are balanced, but when light hits them the balance is upset and that is what makes the electrons move in a uniform way.

How The Solar Electricity Is Made Useful For Your House

A little bit more work has to be done before the electricity can be used in a house though. It comes out as direct current (DC) but houses run on alternating current (AC) so it has to be converted before it can actually be useful.

On the way to the converter, however, it makes a stop in a battery. This is a DC battery, and that’s where the electrical energy from the solar cells are stored, so that it can be used when needed.

If you are interested in becoming helping in the fight against global warming, go to Solar Energy UK to get more information about solar panels. That is the website where Cameron Knill enjoys writing more about renewable energy sources.


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