Sunlight is made of photons, small particles of energy. These are absorbed and pass through the material of a solar cell, or photovoltaic (PV) panel. The photons agitate the electrons in the PV panel. As the electrons begin to move they are routed into a current. This is electricity—the movement of electrons along a path.
The first practical solar cell was developed at Bell Laboratories in 1954. Very reliable. It was used early on satellites. At this stage solar cells were pretty expensive. It is safe to say, though, that the space program could not exist without solar energy.
PV systems are modular, so they can be used in a wide variety of applications—from a wrist watch or pocket calculator to an electric power plant providing electricity to thousands or millions of customers.
PV comes in a variety of forms. Generally a semi-conductor from a silicon source which the sun’s rays hit the large-area diode. Electric current is taken from the device through a grid contact structure that allows the sunlight to enter the solar cell. A contact on the back completes the circuit.
Single-crystal silicon, or crystalline silicon, has been the material of choice for high-performance solar cells. Other materials are continually being tested to reduce the cost.
Morton Solar and Wind installs and maintains several types of PV panels depending on the customer’s needs.