Solar Electrical Power

Solar electrical power works by the conversion of light into other forms of energy. When you think of solar power the first thing that comes to mind is probably solar panels being used to generate electricity. This is known as photovoltaics. However, solar power is used for a lot more than just generating electricity.
Solar power has been used throughout human history for a variety of things:
* Heat engines: Concentrating light to generate heat to drive an engine.
* Space heating: Converting light to heat and trapping it inside buildings.
* Water distillation: Purification of water using evaporation.
* Water heating: Converting light to heat for warming water.
* Photovoltaics: Conversion of light to electricity for a variety of uses.

We’ll be focusing on how photvoltaics work here as I imagine that’s what you’re most interested in. More specifically our focus will be photovoltatic panels. There are in fact multiple types of photovoltaic energy sources though. So, what is a photovoltaic solar cell (PV cell) and how does it convert light to electricity? Quite simply they rely on the photoelectric effect. This is a quantum electronic phenomenon where electrons are emitted from matter after electromagnetic radiation is absorbed. Light is a form of electromagnetic radiation.

Light hits the solar panel and is absorbed by a semiconducting material like silicon. Some of the light is reflected back and lost but a special layer designed to reflect light back at the cell recovers some. Electrons (negative charged) come loose from their atoms (photoelectric effect) allowing them to flow through the material.
Solar panels have a special composition that only allows these electrons to move in a single direction. Now that this negatively charged electron has come loose in its place is a positive charged “electron hole” which flows in the opposite direction. The electron and “electron hole” move in their respective directions until reaching metal plates which are connected. This action creates direct current electricity.
The amount of knowledge that goes into understanding all the details of how solar power works could fill a book and many books exist that cover them more extensively. Check out the environmental impact of solar power as well. However, the above information covers all the basics of know about how photovolatic panels work. If you want to learn more about how solar panels work wikipedia has an excellent detailed explaination that goes very far into the science of each individual part.
I hope you’ve found my explaination helpful and have learned something here today. If you’re interested in other forms of photovoltaic energy you should look up concentrating photovoltaics (CPV) or fresnel lens sterling engines.