How does the Electric Grid Really Work?

The assumption is that every time you flip the switch, press the button or turn the knob, electricity will be there to turn on the lights, the television or the water heater. That simple faith in reliability is the product of a complex electric grid working in three stages: generation, transmission and distribution.

The generation comes from power plants using secondary energy sources such as coal or natural gas as well as renewable energy sources such as wind or solar. Once that process is complete, high-voltage transmission lines carry the electricity to substations, where voltage is lowered for distribution.

Distribution lines then deliver electricity to homes, schools and businesses, where consumers can use it for various purposes and by varying demand. In a way, that demand is what makes management of the grid both incredibly important and incredibly complicated. The grid is an enormous network with the ability to deploy electricity to the right places at the right time using the flexibility of diverse resources to maintain reliability.

In the Midwest, the grid is managed by MidContinent Independent System Operator, Inc. (MISO), which also handles Manitoba, Canada, and a region of the southern United States that includes Arkansas, Mississippi and Louisiana. Other states covered or partially covered by MISO are Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, Montana, North Dakota, South Dakota, Texas and Wisconsin.

MISO, a not-for-profit, member-based organization, helps meet demand by redirecting electricity to where it is needed, dealing with both anticipated and unanticipated outages while serving the 45 million people who depend on MISO every day.

As with any power source, the more redundancies and the more connections at the disposal of the grid operators at the national, regional and local levels, the easier it is to ensure reliability for the end users. Areas where there is only one point of contact to a power source (substation) run a higher risk of a sustained outage.

However, MISO does not own any equipment on the electric grid. That falls on the variety of local municipal or cooperative power providers. The provider maintains the equipment, while MISO acts as an air traffic controller managing the movement of the electricity.

In the end, however, the goal is the same for the grid operator, the generation and transmission source and the consumer provider – safe, reliable, affordable power.


As you read in the previous article, all of our electrical grid is interconnected. Wayne-White Electric Cooperative distributes electricity from the substation to the members' homes. Hoosier Energy provides the generation for our membership.

But Hoosier doesn't have any direct transmission lines to serve our substations, they rely on other utilities transmission lines. All of the energy that our members consume flows through Ameren's transmission grid.

We have had many questions regarding the proposed transmission line project from Fairfield to Mt. Vernon. Although this project is being built by Ameren it will benefit our membership. This line will increase reliability to our service territory by providing an additional connection to the grid. This project will not affect service territory boundaries, so Ameren will not become the electric provider to any of our members with this project.

I understand this project is a concern for many of our members and if you have any other questions my door is always open.