In one hour, enough sunlight falls on Earth to supply electricity for every person, for an entire year!
How Does it Work?
Solar photovoltaics (solar pv) uses the photovoltaic effect to transform light photons from the sun into free electrons that produce an electric current, effectively captured and stored as electricity.
What is the Photovoltaic Effect?
Light beams are made up of photons that contain an amount of energy determined by the wavelength frequency of the light. When a semi-conductive material (like silicon) is illuminated, the photons are captured and bonded with electrons in the semi-conductive material. The electrons are so excited by the photon energy that they exceed the work function (the minimum amount of energy needed to release an electron from the surface of a substance) and are released from the surface of the semi-conductive material. As freed electrons accumulate, they develop into an electric current that can be captured and stored as electricity.
How Many Solar Cells are Needed?
For small items such as a calculator a single solar cell might suffice. If more than one cell is needed, cells can be connected electrically to form a photovoltaic module. A module, or solar panel, is usually enough to support an emergency telephone line. For larger jobs, like powering a house or a business, multiple modules must be connected to form arrays.