Eli5 How does the sun charge batteries to give us power?
In: 0
So the sun can be used to generate electricity in two ways.
The first is relatively simple, using the sunlight to heat up water that then drives a steam turbine. This is the big solar farms you see with the hundreds of mirrors all focusing the sunlight on one point, the get that point very hot.
The second is a bit more complex but can be done on a smaller scale. Your typical solar panel.
Solar panels work like this to put it very very simply. They have a layer of silicon in them. This layer is hooked up to a wire. When the sunlight hits the silicon layer, it excites one of the electrons in the silicon atom, and that now free electron flows into the wire.
There is then another layer (called p-type) in the solar panel that doesn’t get excited by the sunlight, but has extra electrons it can donate to the silicon layer whenever an electron is knocked free, so the silicon layer always has a full stock of electrons to get excited by the sunlight.
This p-type layer won’t take any electrons from the silicon, but then can also be fed by a wire so the electrons is passes to the silicon layer get replenished too.
Basically, electrons in the silicon are excited and have no where to flow but into the wire leading out of the solar panel. Then the p-type layer donated electrons to the silicon to fill up the holes left behind. Then that p-type layer is fed by another wire to keep it stocked up on electrons. Creating a circuit that electricity flows through driven by the sun.
The special part is that p-type layer, that prevents electrons from randomly flowing backwards in the way we don’t want them to go.
Latest Answers