How do solar panels generate electricity?
Solar cells are made up of silicon atoms. Think of atoms as building bricks — like the building blocks of a high school — but because atoms are so small, you need special tools to see them. Solar cells are made from layers of silicon wafers, which are about the size of a dinner plate but much thinner – only about three times thicker than an average human hair.
Turning the silicon layer into a solar panel requires a special fabrication process, in which the silicon layer is heated to 1,000 degrees Celsius, a metal sheet is placed on the back of the layer, and a metal mesh with holes is covered in the solar cell and the side is driven towards the sun.
When the 60 solar cells are ready, they will be fixed to a layer of glass to make solar panels. On average, rooftop solar power systems have 10-50 solar panels, and rural solar farms have millions of solar panels installed.
Each silicon atom contains tiny, lightweight electrons that carry a weak charge. When sunlight falls on a solar panel, it hits one of the electrons and knocks it out of its orbit. The hit electrons are free to move around, but the special construction of the battery means that the electrons can only move in one direction toward the sun.
So when sunlight falls on a solar cell, many electrons will fall out of their orbits and become free electrons, and because of the nature of solar cells, electrons can only move upward, creating a current that can drive household appliances.
The stronger the sunlight that falls on the solar cell, the more electrons will be knocked out of their orbits, and the more electricity will be generated. If the weather is not clear, the number of electrons hit will be reduced, and the current generated will be reduced by 75 percent or more. At night, the solar panels do not produce any electricity, and the power supply is completely dependent on batteries or other power sources.
