Solar PV (PhotoVoltaic) Panels harness the sun’s energy, converting it into electricity to be used in the household. But how do solar PV panels work?
The very first solar cell was created all the way back in the 1880’s by an American inventor by the name of Charles Fritz. Technology has of course advanced dramatically since then, producing much more efficient solar PV panels that are used today, but the scientific principles remain the same. Essentially, the photovoltaic panels use the energy produced by the sun to produce a direct current (DC) that is equivalent to the ‘man made’ electricity we use worldwide.
Photovoltaic (PV) means the generation of an electric current (voltaic) in response to exposure to light (photo). Each solar panel, or array, is made up of many individual PV cells, each of which is capable of producing this current. Electrical currents are produced as a result of the flow of electrons through a material and in the case of solar panels, this may include monocrystalline silicon, polycrystalline silicon and cadmium telluride, among others.
These silicon crystals are thinly cut and arranged on top of one another in layers, producing an electric field allowing the flow of electrons from one side to another, should they be stimulated appropriately. And that’s when the sunlight comes in. Light from the sun (or any other light source) is made up of particles called photons. When these photons hit our solar panels, they stimulate the electrons within the electric field to flow from one side to the other in an electrical current while the electric field causes a voltage. The resultant power can then be used to operate all kinds of devices in the home, from lights to toasters to televisions.
What you see on the roof of a house is not bare silicon though. The solar cells must be protected to prevent them from being damaged by weather or other environmental factors. This protection is provided by a sheet of glass which makes up the outer surface of the panel. This glass must also be coated in an anti-reflective material, since the silicon cells would ordinarily reflect much of the light that falls on them.
Despite all of this wonderful technology, solar panels are still relatively inefficient at producing power from the amount of light that falls upon them. The current rate of efficiency is around 20%, depending on the type of silicon used in the panels, but this figure is expected to rise dramatically over the coming years as technology in the renewable energy industry advances.
For a more in depth look at how solar panels work, take a look at this how stuff works article.