ComEd Commercial Electricity Guide

ComEd is the electric delivery utility for much of northern Illinois. Eligible business customers may buy electricity supply from utility default service or a retail supplier, while ComEd continues to deliver electricity, maintain the meter and distribution system, and handle outages.

This page is a navigation and decision guide. Use the current ComEd rates and rules, the account's actual bill, and the Illinois Power Agency supply-rate page for time-sensitive values. For the statewide overview, see commercial electricity in Illinois.

What changes and what does not when supply changes

A supplier switch can change the contracted supply economics and related terms. It does not replace ComEd as delivery utility. Distribution, metering, taxes, and many utility riders remain on the bill under applicable tariffs.

That distinction prevents a common error: applying a supply-price difference to the entire bill and calling the result savings. On a commercial account, delivery, capacity, transmission, and taxes can be a substantial share of the total, and none of those move when only the supply price changes. The disciplined comparison isolates the supply line, matches delivery dates, and leaves every delivery-side charge out of any claimed difference.

How supplier choice works in ComEd territory

Eligible ComEd commercial customers can stay on utility default supply or contract with an Alternative Retail Electric Supplier (ARES) — a company licensed by the state to sell the supply portion. When an account is with an ARES, ComEd still delivers the electricity, maintains the distribution system and meter, reads the meter, and bills its regulated delivery charges; the ARES prices only the supply. Choosing an ARES is a supply-economics and contract-terms decision, so apply the same procurement and contract review discipline to it that you would to any commodity purchase. Eligibility depends on the account's rate class and size, which you confirm from the bill and ComEd's tariff rather than assuming.

Read the bill in four groups

1. Account and meter: service address, class, billing days, meter, supplier.
2. Usage and demand: kWh, billed kW, and any other demand fields.
3. Supply: energy, transmission, capacity treatment, adjustments, and supplier fees.
4. Delivery and other: customer, distribution, metering, riders, taxes, credits, and other utility items.

Use our field-by-field ComEd bill guide to build a consistent 12-month history.

Utility supply benchmark

The Illinois Power Agency procures electricity for eligible residential and small commercial default-service customers. The IPA updates its procurement plan annually and links current ComEd supply information. Confirm that the specific account is eligible for the benchmark being used.

When comparing a retail supplier, match delivery dates and identify whether energy, PJM capacity, transmission, line losses, renewable obligations, ancillary services, and fees are included. Use the Price to Compare decision guide and the offer-comparison worksheet.

PJM capacity and the account PLC

ComEd participates in PJM, the regional transmission organization that runs the wholesale market and the capacity auction for its footprint. Wholesale capacity auction outcomes can affect retail supply costs, but the result is filtered through the delivery year, the account's capacity obligation, the contract, and utility or supplier calculations before it reaches a bill.

The account-level driver here is the Peak Load Contribution (PLC) — a capacity tag derived from the account's demand during the system peaks that PJM uses to set obligations. Two accounts on the same rate with the same annual kWh can carry different capacity costs if their PLC differs, because the PLC reflects when load occurs relative to the peak, not just how much. That is why load shape, not just total consumption, matters when a supplier prices an offer. PJM publishes auction and planning materials at pjm.com; those are wholesale inputs, not customer bill rates.

Do not treat a PJM auction clearing price as a bill rate. Read the PJM capacity and ComEd business bill guide for PLC, delivery-year, and contract questions, and the three-buckets guide to capacity, energy, and transmission for how those components sit side by side in a quote.

Demand charges and delivery

Many ComEd commercial accounts are billed on demand — a charge tied to the highest measured kW in a period — in addition to energy. Demand-based delivery charges are set by ComEd's tariff and stay with the utility regardless of who supplies the electricity, so a supplier switch does not lower them. Understanding demand is often where the larger operational opportunity sits, because reducing peak kW can move a delivery charge that a supply contract never touches. See the commercial demand charges guide for how demand and any ratchet provisions apply, and keep demand separate from the PLC capacity tag above: one is a delivery-side billing determinant, the other a wholesale capacity obligation.

Usage and interval data

Monthly bills are sufficient for basic reconciliation, not hourly load-shape pricing or peak investigation. Request account-authorized interval data when available, preserve the raw export, document timestamps and units, and reconcile monthly sums to billed kWh.

Use the interval data validation guide. ComEd's Hourly Pricing FAQ is an official source for hourly usage and price concepts; program eligibility and suitability must be evaluated separately.

2026 efficiency incentives

ComEd publishes current business program rules and applications. Its 2026 Standard customer fact sheet contains time-sensitive private/public sector deadlines and possible additions for eligible projects. Some pre-application dates had already passed by July 2026. Review the dated Illinois incentives guide and confirm the project directly with ComEd before ordering equipment.

Procurement file checklist

• 12 to 24 months of bills.
• Interval data and validation results when available.
• Executed supply contract and amendments.
• Meter/account inventory and facility changes.
• Applicable utility benchmark and effective dates.
• Supplier proposals normalized to one charge scope.
• Contract red flags and legal review.
• Compensation disclosure.
• Enrollment confirmation and first-bill reconciliation.

Confirm the territory from the bill

Northern Illinois is ComEd; central and southern Illinois is Ameren Illinois. Near the boundary, do not assume — read the utility name on a recent bill. This matters because the market context differs by utility: ComEd is in PJM and Ameren is in MISO, so a capacity assumption, benchmark, or supplier model built for one does not carry over to the other. The bill also confirms the exact rate class and account eligibility that any accurate comparison depends on.

Outage and safety

ComEd remains the delivery and outage contact regardless of retail supplier. Follow ComEd's official reporting and emergency channels; a supplier or broker does not repair electric service.

Sources

• ComEd — Rates and Rules
• ComEd — Hourly Pricing FAQ
• Illinois Power Agency — Electricity Supply Rates
• PJM — regional market and capacity information
• Illinois Commerce Commission

Source check date: August 1, 2026. Verify current tariffs, supply values, program rules, and account eligibility.