This is the second blog in this series, so if you have not seen my blog on geothermal energy, go check it out after this.
Solar energy is one of the renewable energies that we will rely on more and more as we shift away from fossil fuels. But how does solar energy actually work? How can simple black panels turn sunlight into energy?
First, we must talk about the construction of solar panels. Solar panels are made up of smaller units called solar cells, which are usually made of silicon. Silicon is used because it is one of the most abundant elements on earth and the bonds between silicon atoms are very strong. These bonds hold electrons in place so that no electrical current can flow. In the solar cell, there are two different layers of crystalline silicon that are pressed between two conductive layers. The top layer of silicon (negative charge N-type) has extra electrons, and the bottom layer (positive charge P-type) has extra spaces for electrons (holes). The electrons can move freely across the P/N junction, which is where the two layers touch.
When a beam of light, which is filled with tiny, fast-moving particles called photons, hits the solar cell with enough energy, it can knock an electron from its bond, creating a hole. The negatively-charged electron and the positively-charged hole are now free to move around, and the electric current draws the electron to the N side while the hole is drawn to the P side. These electrons are collected at the conductive layer at the top of the N side and pushed through an external circuit, creating power. Once an electron is pushed through the circuit, it travels through the other conductive layer. When it reaches the P side of the cell, it finds a hole. This means that nothing is used up, and the same electron can go through the circuit many times.
Learn more: https://www.youtube.com/watch?v=xKxrkht7CpY