Me and my partner have been travelling round Europe all summer in our converted van and have been mostly relying on our solar panels for our energy.
This got me thinking, how the hell does Solar Power/Energy work?
In: 2
Let’s start with how fluorescence works, before we jump into the photoelectric effect. When you shine light on an object, the photons can interact with the electrons in the atoms on the outside of the object. In a fluorescent effect, the photons bump the electrons into a higher energy state absorbing the photon’s energy and destroying it. Electrons don’t like that, and they pop back where they belong. Sometimes the pop back warms the object, but with a fluorescent object the pop back creates a photon, the specific color of the fluorescence you see.
Now that you can see how light in leads to higher energy electron leads to light out, you can ask “What about if I put in more energy?”. Special materials aren’t as tough as fluorescent paint molecules, and when light hits them it bumps the electron so hard it comes off. Now you’ve got a loose electron wandering around, trying to find the atom it came off of. As soon as it does, everything is back to normal.
Now you engineer a very thin slab of this material and put a transparent electrode on the top of it. Now when the electron pops off, it is conducted away. It is forced to go through a circuit before it can get back to the thin slab of material and find its way back to where it goes. This is how a solar cell works. Light bumps a bunch of electrons loose, they are forced to go through a circuit (where they do some useful work) before they can get back home again.
Electricity is electrons moving together in one direction. A solar panel allows light from the sun (photons) to knock electrons off their atoms and get them moving in one direction using a sort of one-way valve.
Your Panel consists of the blue stuff and the small strips of metal.
The metal strips catch energy “created” by the sun (electrons) and feed it to your panel output.
The blue parts are made of a special material (semiconductor) that is “doped” with extra “free electrons”. These free electrons don’t have a proper place to stay (no atom) and are just hanging out in the material. When the sun shines, some sunrays hit those electrons and give them their energy. This extra energy makes the free atoms go wild, they’re in a high state of energy and want to party. They are driven towards the small metal strips, because that’s where the party is! However, they have to get there quickly because since they are so wild, they don’t know what they’re doing and will happily shoot away the extra energy in form of a lightray. Luckily, quite a few of them do make it and those party-electrons power your devices. Unfortunately this also gets them off of their wild party-state and they go back to the solar panel.
Researchers try to develop panels where as many sunrays as possible (the sun gives lightrays in all colours of the rainbow, which combined look white) can get as many free electrons as possible to the wild party state and to be absorbed at the metal strips.
My first eli5 attempt and I chose a topic that takes a full university lecture and background in quantum mechanics to really understand xD Hope it makes any sense at all!
edit: maybe also type in “how do solar cells work” into YouTube to get a video that visualizes it.
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