What Goes on Inside a Solar Panel?

A solar panel is a device which converts light into electricity. They are erected on roofs or buildings which face the sun. Many scientists call these solar panels photovoltaic’s, which means in simple terms “light electricity”. To understand what goes on inside a solar panel you have to understand what they are made of.

A solar panel is made of a collection of solar cells which generate electricity directly from visible light which relies on the photoelectric effect. The photoelectric effect is the name given to describe what happens when light is shone onto a certain type of material which absorbs photons but releases electrons. When these free electrons are captured, you get an electric current which can be used as electricity. The famous physicist Einstein actually won the Nobel Prize in 1921 for work explaining the photoelectric effect.

Solar cells are based on semiconductor physics. Semiconductors are a class of materials such as silicon, carbon and germanium which can conduct electricity making them a good medium for the control of electrical current. Crystalline silicon is mainly used in solar cells and the material just happens to be one of the most common elements on earth. An individual solar cell is designed with a positive and negative layer to create an electric field just like in a battery. Sunlight is made of photons, so as photons are absorbed into the cell, their energy causes electrons to become free which then move towards the bottom of the cell and exit on the connecting wire. This flow of electrons is what we call electricity. The combination of these solar cells and photovoltaics panels create electricity which you can harness to use throughout your home.

The actual amount of electricity which is generated by these cells will depend on the amount of light falling onto them. This of course is determined by the weather and the time of day. Because of which storing the energy will be necessary. Solar panels will need to be positioned so that they catch sun light as much as possible. They will need to be south facing to benefit from full direct sunlight; but you can still harness the energy from the sun with panels facing south east or south west. Also direct sunlight is not a necessity as UV light which can penetrate through clouds will still generate electricity but not as much as a cloudless day.