Science Topic "How Electricity works"

How Electricity Works

Electricity generation 

The electricity we use every day is generated in power plants by converting resources such as water, sun, coal, oil, natural gas and wind into electrical power. It is generated by a large magnet that spins inside coils of wire. High pressure steam or water is used to turn a turbine – a large fan – attached to the generator to get the magnet spinning. As the magnet rotates inside the loops of wire, electric current is produced. 

The electrical system 

This electric current is sent through a vast power grid of high-voltage transmission lines to a substation in your area. At the substation, the voltage is reduced and overhead or underground distribution lines carry the electricity to your home or work.

Power lines leading to residential areas generally carry 4,200 to 34,500 volts. Within neighborhoods, the voltage is decreased further with step-down transformers located on the top of poles (or in a vault on the ground) to the typical 120 to 240 volts for safe home use.

How electricity works

Electricity always seeks to go into the ground as the path of least resistance – and that's when injury and harm can occur.

Conductors, such as power lines, allow electricity to move freely through them, while insulators are resistant to the flow of electricity. Some examples:

• Conductors – metal, water, things that are wet, trees (because they contain moisture), people (because our bodies contain water)
• Insulators – rubber, glass, porcelain, plastic

Within the home, it is typical to have conductors covered with an insulator, such as a rubber-covered electric cord. However, this does not guarantee safety. A variety of circumstances can compromise the integrity of insulators.

If an electrical injury occurs 

The rule of thumb for an electrical shock victim is: Do not attempt to aid the victim until the source of the current is shut off or the victim is no longer a path to ground. Touching a person in this situation provides the current with another path to ground, through the rescuer. Call 911 immediately and warn others to stay away.