Solar Panels — How it Works
Photovoltaic Solar Panel Technology
The type of solar panel you normally see on people’s roofs are called Photovoltaic Solar Panels — photo meaning light, and voltaic meaning to do with electricity. As the name suggests, Photovoltaic (or PV) panels convert light directly into electrical energy. So how do they work? How much sunlight do they need?
Solar cells are small devices which can convert sunlight into electricity. Several cells connected together and fixed in a frame make a solar panel (or a module), which can produce a larger, useful amount of power.
So How Do Solar Panels Work?
Inside a solar cell you have two wafer-thin layers of silicon crystal, placed on top of each other to make a sort of silicon sandwich. The top layer is specially treated so that its atoms are unstable — they have one too many electrons that they would really like to get rid of. The bottom layer has also been treated, but the atoms have a few empty spaces that could really do with an electron to fill them. When sunlight hits the top silicon layer, it ‘excites’ the electrons and gives them enough energy to move.
The electrons begin to flow from the top layer to the bottom. And as we know, when a bunch of electrons start to move along in the same direction, we have electricity. Put two metal contacts on either side of the silicon sandwich and we have electricity moving through a circuit. The current from the solar panel system has to go through an inverter, to convert it from DC to AC before it can be pumped into your house and used to run appliances.
PV Solar System Components
Every solar PV system is made up of several components: solar panels (or ‘modules’), an inverter, a meter, and your existing consumer unit. Here’s how it works: