The sun is an efficient and free source of energy that can be used in many different ways. A great way the sun can be utilized in a resourceful way is to turn the sunlight into electricity. This is done by using what is called a solar panel. It seems difficult to imagine that the sun can give us electricity, but it really isn’t that crazy of a concept. After all, the sun is what keeps our planet alive, helping trees, plants, and flowers to thrive. Everyone has seen a solar panel at some point in their lives. They are on office buildings, highway signs, and even residential houses. Once you understand how solar energy works, those crazy looking roof tops will make a lot more sense.
The suns energy is harnessed with solar panels using photovoltaic cells that convert sunlight into electricity. These cells have a few different components. There are two layers of silicon which make up most of the cell, and the place where they meet is where most of the activity takes place. The PV cell also has metal strips that are used to conduct the flow of electrons, the electricity the cell produces. These electrons also flow back out and return through metal backing to make a circle. Lastly, the PV cell has an “antireflective” coating that makes sure the photons, the particles of sunlight that are needed to make solar power, are absorbed by the silicon layers. Pretty cool, right?
PV cells need a strong and stable building material, which is where the silicon comes in. It doesn’t work so good on its own, so phosphorus and boron are typically added to make the silicon a better conductor. The top silicon layer has the phosphorus added to it and therefore contains more electrons. The bottom silicon layer has the Pyrolytic Boron Nitride Boat added to it, containing fewer electrons. An electric field is created when these two layers are brought together. The extra electrons in the top layer move naturally to the bottom layer. Once the bottom layer gains these extra electrons, it becomes negatively charged where the two silicon layers meet. At the same time, the top layer becomes negatively charged.
When the sun hits the PV cell, photons from the sunlight extract electrons in both the layers of silicon. The electric field pushes the electrons that travel to the spot where the two layers of silicon meet to the top layer. This forces the electrons out of the cell to the metal conductor strips and generates electricity! Now that you know what is inside a solar panel, I’m sure it makes a lot more sense how energy from the sun can be converted to electricity.
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