Supporting Customers

The journey of electricity

July 19, 2019

When you flip a switch or power on the TV, electricity is instantly there. But it must complete an extensive journey to get to your home. Because we use electricity to power nearly every aspect of our lives, it’s important to understand the basics.

The two parts of electricity are supply and distribution. Supply is how electricity is produced, and distribution is how it’s delivered to homes and businesses.


The process of creating electricity is typically performed at power plants Using a device called a turbine generator, electricity is generated by burning fossil fuels, nuclear reactions or through renewable methods such as solar, wind and more.



Electricity from the power plant is brought to you by a network of power equipment and lines.

Electricity leaves the power plant on high power transmission lines spanning between tall towers. Transmission lines transmit electricity to substations, where transformers may convert high voltage to low voltage. Overhead or underground distribution service lines then carry electricity to individual homes and businesses.

ComEd has more than 5,300 miles of overhead transmission lines, 34,900 miles of overhead distribution lines and 29,700 miles of underground distribution lines! 


See the diagram below to help understand the process of electrical supply and distribution.

 Key terms:


Turbine generator: A device that uses steam, heated gases, water flow or wind to cause a spinning motion that activates electromagnetic forces and generates electricity.

Electromagnetic:  Electrical and magnetic forces or effects produced by an electric current.

Power plant: A facility used to generate electrical power with the help of one or more generators (e.g., wind, solar, burning fossil fuels or nuclear reaction).

Substation: A subsidiary station where electricity is transferred from high voltage to low voltage or vice versa for distribution purposes.

Transformer:  Manipulates the level of voltage flowing through any point in a power grid.

Grid: The electric transmission and distribution system that links power plants to customers.                                

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