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How Does Energy Choice Work in Illinois?

Learn how Illinois energy choice lets residents pick a supplier while Commonwealth Edison or Ameren Illinois still delivers power and handles outages.

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Written by Hash Manesia

Published on Oct 17, 2026

9 min read

Reviewed by Jeff Mahoney

How Does Energy Choice Work in Illinois?

How Does Energy Choice Work in Illinois?

What Does Energy Choice Mean for Illinois Residents?

Energy choice means you can pick who sells you the electricity you use, instead of being stuck with one company. Illinois runs a deregulated energy market, which separates the business of generating and selling power from the business of delivering it to your home. Residents get to shop around for a supplier while the physical wires and poles stay managed by the same local utility.

This setup exists because lawmakers split the electricity market into two functions: supply and delivery. A supplier competes for your business and sets its own pricing structure. The delivery side stays regulated since it would be wasteful and impractical for multiple companies to build competing power lines in the same neighborhood.

Utility vs Supplier: Who Does What?

A utility delivers electricity to your home and handles outages, while a supplier sells you the actual energy commodity. These are two separate roles performed by two separate types of companies, and mixing them up leads to confusion about who to call when something goes wrong or when you want to change your rate.

  • The utility owns and maintains the poles, wires, and meters that physically carry electricity to your property.
  • The utility responds to outages, handles emergency repairs, and sends you a bill that includes delivery charges.
  • A supplier is the company you choose to purchase the electricity itself, separate from how it reaches you.
  • Switching suppliers does not change who shows up to fix a downed line or restore power after a storm.

How Commonwealth Edison and Ameren Illinois Fit Into the Picture

Commonwealth Edison and Ameren Illinois remain your electric delivery utilities no matter which supplier you choose. They maintain the infrastructure, read your meter, and respond to outages across their respective service territories. Choosing a different supplier for the energy commodity itself does not change your connection to either utility.

Your monthly bill may still arrive from Commonwealth Edison or Ameren Illinois even after you switch suppliers, since many billing arrangements keep delivery and supply charges on one combined statement. The utility simply passes along the supply charges from the company you picked, while continuing to bill you separately for delivery.

What Happens If You Don't Choose a Supplier?

If you never select a supplier, you're automatically placed on default service through your utility. This fallback arrangement means you still get reliable power without interruption, since Commonwealth Edison or Ameren Illinois arranges the supply on your behalf until you decide to shop for an alternative.

Default service isn't a penalty or a sign that something went wrong. It's simply the standard path for anyone who hasn't actively picked a supplier. You can switch away from default service at any point, and you can also return to it later if your supplier arrangement ends or changes.

The Role of the Illinois Commerce Commission

The Illinois Commerce Commission regulates the state's energy market and oversees which suppliers are licensed to operate. The ICC sets rules for how suppliers must disclose pricing and contract terms, and it provides a channel for residents to file complaints or resolve disputes with a supplier or utility.

Because the ICC licenses suppliers before they're allowed to sell electricity in Illinois, residents have a baseline level of oversight built into the market. The commission also monitors utility operations, including reliability standards and billing practices, which keeps both sides of the delivery-supply split accountable.

Understanding Fixed vs Variable Rate Plans

Fixed and variable are the two basic rate structures you'll encounter when comparing supplier offers. A fixed-rate plan locks in a per-unit price for the duration of a contract term, so your supply charge per unit doesn't change even if market prices shift. A variable-rate plan adjusts periodically based on market conditions, meaning your rate can rise or fall from one billing cycle to the next.

  • Fixed-rate plans offer predictability, since the per-unit price stays the same throughout the contract term you agree to.
  • Variable-rate plans can fluctuate monthly, reflecting changes in wholesale energy costs or seasonal demand patterns.
  • Contract length, cancellation terms, and renewal conditions differ by supplier and should be read carefully before signing.
  • Your household's usage pattern and tolerance for rate fluctuation both factor into which structure suits you better.

How to Evaluate and Switch Suppliers

Switching suppliers starts with comparing contract terms, rate structures, and any fees tied to cancellation or enrollment. Once you pick a new supplier, that company typically handles the enrollment process with your utility, and your service continues without any interruption in power delivery during the transition.

Before switching, check the length of the contract, whether the rate is fixed or variable, and what happens when the term ends. Some plans renew automatically at a different rate, so understanding the renewal terms upfront helps you avoid surprises. Keep a copy of your contract details in case questions come up later.

Gatby helps Illinois residents find and connect with suppliers that match their preferences, without ever selling energy itself. Gatby's role is to simplify the comparison process so you can evaluate options like contract length and rate structure in one place, rather than researching each supplier separately.

Gatby doesn't generate or deliver electricity, and it doesn't act as your utility or your supplier. Instead, Gatby connects you with licensed suppliers operating in Illinois, helping you understand plan details so you can make a decision that fits your household's needs.

Frequently Asked Questions

What is a deregulated energy market?

A deregulated energy market separates the sale of electricity from its delivery, allowing residents to choose which company supplies their power while the local utility continues to maintain the lines and respond to outages. In Illinois, this structure means you aren't locked into one company for your electricity supply. The utility still owns the physical infrastructure and handles your connection, but a separate supplier competes for your business by offering different rate structures and contract terms. This split exists because building duplicate power lines across the same neighborhood would be impractical, so delivery stays regulated while supply becomes competitive. Understanding this distinction helps you know who to contact for different issues, whether it's a billing question about your rate or an outage affecting your service.

Do Commonwealth Edison and Ameren Illinois still deliver my power if I switch suppliers?

Yes, Commonwealth Edison and Ameren Illinois continue delivering electricity and maintaining infrastructure in their service territories no matter which supplier you choose. Switching suppliers only changes who sells you the energy commodity itself, not who maintains the poles, wires, and meters connected to your home. These utilities still read your meter, respond to outages, and often appear on your bill even after you switch, since delivery and supply charges are frequently combined on one statement. Your physical connection to the grid and your relationship with the utility for repairs and emergencies stays exactly the same. This separation is a core feature of how the deregulated market works, letting you shop for supply without ever worrying about who shows up when the power goes out.

What happens if I never choose a supplier in Illinois?

If you don't actively select a supplier, you're automatically placed on default service, which is arranged through your utility, either Commonwealth Edison or Ameren Illinois depending on your location. This ensures continuous power without any gap in service, since the utility arranges the supply on your behalf. Default service isn't a punishment or an error; it's simply the standard fallback for residents who haven't shopped for an alternative. You remain free to switch to a different supplier at any time, and if a supplier arrangement ends for any reason, you can return to default service without losing power. Many residents stay on default service indefinitely, while others choose to compare supplier offers to find a contract structure that better fits their preferences.

What does the Illinois Commerce Commission actually do?

The Illinois Commerce Commission regulates the state's energy market, licenses suppliers before they can operate, and oversees utility practices like reliability and billing. The ICC sets disclosure rules so suppliers must clearly explain pricing and contract terms before a resident enters an agreement, which gives residents a baseline of protection when comparing offers. If a dispute arises with a supplier or utility, the ICC provides a channel for filing complaints and seeking resolution. The commission also monitors how utilities maintain their infrastructure and respond to outages, holding them accountable on the delivery side of the market. Because every supplier operating in Illinois must be licensed by the ICC, residents can check that any company they're considering has met the state's regulatory requirements before entering a contract.

What's the difference between a fixed-rate and variable-rate supplier plan?

A fixed-rate plan locks in a per-unit price for your electricity supply for the length of your contract, so that price doesn't change even if market conditions shift. A variable-rate plan, by contrast, adjusts periodically based on wholesale market conditions, meaning the rate you pay can go up or down from one billing cycle to another. Fixed plans offer predictability, which can make budgeting easier if you prefer knowing your supply rate won't change mid-contract. Variable plans offer more flexibility but come with less certainty, since your charges can shift with market conditions. When comparing plans, it helps to look closely at contract length, renewal terms, and any cancellation fees alongside the rate structure itself, since these details affect the overall value of either option.

How does Gatby fit into the energy choice process in Illinois?

Gatby helps Illinois residents find and connect with suppliers by simplifying the comparison process, but it never provides energy or acts as a utility or supplier itself. Gatby's role is to help you evaluate details like contract length and rate structure across multiple supplier options in one place, rather than requiring you to research each company individually. This saves time when you're trying to understand what's available in your area and how different plans compare. Gatby doesn't deliver electricity or generate power, and it doesn't replace the role of Commonwealth Edison or Ameren Illinois, which continue handling delivery and infrastructure regardless of your supplier choice. Instead, Gatby acts as a resource to help you make an informed decision about which licensed supplier might fit your household's needs and preferences.

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Table of Contents
What Does Energy Choice Mean for Illinois Residents?
Utility vs Supplier: Who Does What?
How Commonwealth Edison and Ameren Illinois Fit Into the Picture
What Happens If You Don't Choose a Supplier?
The Role of the Illinois Commerce Commission
Understanding Fixed vs Variable Rate Plans
How to Evaluate and Switch Suppliers
How Gatby Can Help You Navigate Energy Choice
Frequently Asked Questions
Related reading
Hash Manesia's Headshot'
Written By
Hash Manesia
Energy Market Analyst
Hash Manesia is a Growth Associate at Gatby and a 2022 graduate of the University of Texas at Austin, where he earned a B.S. in Electrical and Computer Engineering.

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