Commercial Energy in Chicago, IL: ComEd, Peoples Gas & Supplier Choice

Chicago is the anchor of Illinois' commercial energy market — a dense mix of office towers, restaurants and hospitality, retail, manufacturing, warehousing, healthcare, and institutional accounts, all drawing electricity and natural gas across the city every day. For a business operator, understanding who delivers that energy, who can supply it, and how the two roles differ is the foundation for making an informed procurement decision. This page lays out how commercial energy works in Chicago in plain terms and points to the primary sources worth confirming for a specific address.

Utilities in Chicago

• Electricity: ComEd (Commonwealth Edison) is the delivery utility for Chicago and the rest of northern Illinois. ComEd's electric system sits in the PJM Interconnection, the regional grid operator for the area. Eligible commercial accounts can choose a competitive supplier for the supply portion of their electricity. See the ComEd commercial electricity guide.
• Natural gas: Peoples Gas — formally The Peoples Gas Light and Coke Company — is the delivery utility for the city of Chicago. Peoples Gas runs the Choices for You program, under which eligible customers can select a licensed alternative gas supplier while Peoples Gas continues to deliver the gas. See the Peoples Gas commercial service guide.

Both utilities can be confirmed on a recent bill. Because service territories follow infrastructure rather than city limits in every case, always verify the delivery utilities for the exact service address before acting.

Supply versus delivery, and how choice works here

Every Chicago commercial energy bill is really two jobs bundled together. Delivery is the regulated service the utility provides: ComEd owns and maintains the poles, wires, transformers, and electric meters, and Peoples Gas owns and maintains the gas mains, service lines, and gas meters. Delivery covers moving the energy to your building, keeping the network in good repair, reading the meter, and responding to outages and gas emergencies. Delivery charges are set through regulated rates and do not change based on which supplier you use.

Supply is the commodity — the electricity and the natural gas themselves. This is the portion open to competition. On the electric side, an eligible commercial account can buy supply from a licensed Alternative Retail Electric Supplier (ARES) rather than taking ComEd's default supply. On the gas side, the Peoples Gas Choices for You program lets eligible customers buy the gas commodity from a licensed alternative gas supplier. In both cases the delivery utility stays exactly the same, and so does its responsibility for reliability and emergencies. A supplier contract only sets the price and terms of the supply portion of the bill. To understand the mechanics in more depth, see how Illinois commercial electricity choice works and how commercial natural gas choice works in Illinois.

Crucially, choosing a supplier changes nothing about who keeps the lights on or who responds to a gas leak. If a storm knocks out power, ComEd restores it. If there is a gas emergency, Peoples Gas responds. The competitive supplier never touches the physical network.

What shapes commercial energy costs in Chicago

Several factors influence what a Chicago business pays, and they vary widely by account type:

• Rate class and account size. A small storefront on a general-service rate has a very different cost structure than a large demand-billed facility. The rate class on the bill determines which charges apply and how they are calculated.
• Demand charges. Many commercial accounts are billed not just on total kilowatt-hours but on peak demand — the highest rate of draw in a billing period. Two businesses using the same total energy can pay differently if one has sharper peaks, so the rate class and demand structure both matter.
• Load shape and hours of operation. When a business uses energy matters, not just how much. A restaurant, a warehouse running one shift, and a 24-hour facility each present a different load shape that affects supply pricing.
• PJM market dynamics. Because ComEd sits in PJM, wholesale capacity and energy market conditions in that region influence supply pricing over time. These are market outcomes rather than fixed line items you control, but they are part of the backdrop for any supply decision.
• Natural gas seasonality. Gas demand for heating and process load rises in winter, which is why the gas account is worth reviewing on its own terms alongside electricity.

None of these factors resolve into a single number without looking at a specific account's bills and usage. That is the point of gathering real data before pricing anything.

What a Chicago business should gather

Before requesting pricing or comparing suppliers, assemble the following:

• A recent electric bill and a recent gas bill for each service address.
• Account numbers and meter numbers.
• The rate class for each account.
• Any current competitive supplier contract and its end date.
• For demand-billed electric accounts, 12 months of usage history and interval data if the utility can provide it.

This packet does two things. It confirms the delivery utilities and rate classes, and it gives a supplier enough detail to quote the supply portion on matched terms — the same volume, the same term length, the same structure — so that offers can be compared honestly rather than on headline numbers alone.

Getting started

Begin by confirming that ComEd is the electric delivery utility and Peoples Gas is the gas delivery utility for your address, then determine whether each account is energy-only or demand-billed. From there, pull the 12 months of bills and usage described above and the account can be reviewed and priced through a disciplined commercial energy procurement process that compares supply on matched terms while delivery stays with the utility.

No specific savings, rate, or outcome is promised in advance. The goal is a clear, apples-to-apples comparison and a supply arrangement suited to how a Chicago business actually operates — with ComEd and Peoples Gas continuing to deliver the energy and stand behind the network either way.