In order to understand electricity we need to start with the fundamental building blocks of all matter - atoms. Atoms are made up of protons, electrons and neutrons, and each particle has a charge:
Let's look at the charge-carrying particles only (protons and electrons).
The atom in Figure 1 has an equal number of protons and electrons. The overall charge of this atom is neutral or zero because the protons and neutrons cancel each other.
If an atom does not have an equal number of protons and electrons, it will have an electrical charge. This charge will depend on the combination of electrons and protons contained in the atom. A greater number of protons will create a positive charge, while a greater number of electrons will create a negative charge (Figure 2).
Atoms always try to balance their charge. They want to be neutral, or have no charge. Therefore, if an atom with a negative charge nears an atom with a positive charge, the positively charged atom will pull electrons from the negatively charged atom in an attempt to become neutral.
When we look at a chain of atoms, we understood that electrons are passed or shared between the atoms. This occurs because all atoms strive to become neutral (Figure 3). Electrons can move through this chain by adding electrons to one end and removing them from then other. This passing or sharing of electrons creates an electron flow and this is electricity!
Transmission of Electricity*
Generating stations (commonly known as power plants) produce electricity at 20,000 volts, or some other predesigned level. To overcome the loss of energy as it travels many miles from the generating station to your city, they boost the voltage level (known as transmission voltage) to 138,000 volts.
When the electricity reaches your city, a transmission substation converts the energy to a lower transmission level (69,000 volts).
Once the electricity gets close to its destination, the utility will use a distribution substation to reduce the voltage level to 13,800 volts. When that power reaches the pole outside your home, the utility uses a distribution transformer to reduce the voltage so it is useful to you to run your appliances (120 volts).
What Does This All Mean?
The utility saves money by transmitting the electricity at high voltage levels, and your needs are met by having the 120 volts supplied to your home. The trip form the generating station to your home, along with all of the voltage changes that need to be made, and the devices that protect the utility's system, is made possible through the use of electrical system products. Cooper Power Systems produces most all of the products that makes this possible.
*Based on an U.S. transmission