Feature Articles

The report for the 12 months through May 2026 suggested somewhat robust competition for retail commercial customers. The market has been deregulated for 20 years.

Slightly over two-thirds of all power supplied in ComEd comes from an alternative supplier, while the proportion is three-quarters on the Ameren system.

The quantity of supply provided to non-residential customers in the small, medium, and large categories remained relatively steady in both utility territories.

The smallest customers on both systems, or those with demand of up to 100 Kw, have been turning away from the competitive market over the last five years.

Changes in the electric supply market from 2023 to 2025 resulted in an overall decrease in competitiveness within the marketplace, the commission said. Non-residential markets have a moderate concentration among suppliers.

Illinois had 96 certified alternate suppliers last year, compared with 93 the year before.

The number of active suppliers serving both ComEd or Ameren has declined since 2022, while the number of agents, brokers and consultants with active licenses moved up in that period and was 392 at the end of May.

ComEd Commercial Market Gains Were Robust

The number of commercial customers using an alternate supplier to Com Ed increased by 36.7% to nearly 875,000 for the 12 months ending in May, the report said, while their usage grew by 21.7%.

Ameren commercial customers with an alternate supplier fell by 4.5% to 81,488, while their usage fell by 1%.

Suppliers to customers considered very large commercials in the Ameren and ComEd territories faced more competition during the report period, the commission said, as shown in a lower value of the Herfindahl-Hirschman Index.

The index is a broadly accepted economic measure of market concentration. The commission’s analysis included ComEd switching activity for the 1MW to 10MW customer class and Ameren switching activity for the 1MW to 3MW and 3MW to 6MW customer classes combined.

For all non-residential customers of Ameren, quantities of power provided by alternate suppliers have ranged from 86% to 88% of the total from 2020 to mid-2026.

In the ComEd territory, that proportion was 65% in 2020 and has risen to the low-80% area in each of the last five years ending in May 2026.

Alternative suppliers in the MidAmerican Energy service territory were not included in the report because of its small size in Illinois. A separate document found 63 commercial customers in that area had chosen retail suppliers as of June 30.

Residential Markets Contract in Illinois

Residential customers in the state do not appear to show the same level of interest in competitive power supplies.

About 19% of residential customers in the ComEd area are served by alternate suppliers, a proportion that has been fairly stable in the past five years. In 2014, that level was 70%.

Just under 40% of customers in the Ameren territory have moved away from utility supply, down by about 15 percentage points in that time.

Residential customers using an alternate supplier on the ComEd system fell by 1.1% last year to 715,720, the report said, while their usage was down 2.4%.

The number of residential customers within ComEd with alternate suppliers has fluctuated, going from virtually none in 2011 to more than 3 million in 2013, and decreasing to less than half of that number by 2026.

Ameren residential customers with another supplier fell by 6.7% to 421,710, while their usage fell by 7.3%.

The quantity of electricity provided to residential customers decreased to 9% of the total book of business of alternate suppliers in the ComEd territory for the 12 months ending in May, and 14% of the total usage in the Ameren territory.

In 2019, residential customers represented 15% of the total quantity supplied by alternate suppliers in Com Ed, and 19% in Ameren.

The residential customer category within the ComEd territory was less competitive in the period of the report, which the commission deemed “significant enough to shift the designation from moderate concentration to high concentration.”

The three largest suppliers in the ComEd territory had 50% of the residential market in May, the same as two years ago. Fifty-one suppliers have less than a 5% share.

Commission Report Analyzes Residential Costs

Power bills may play a role in declining residential account interest.

The report said that residential customers in the ComEd territory with alternate suppliers paid about 1.82¢/kWh more when compared to the ComEd price to compare, and about 1.28¢/kWh more when including the state’s purchased energy adjustment.

The adjustment is a monthly fluctuating true-up mechanism for the utility, matching incurred supply costs to actual received supply revenues. The adjustment becomes a credit in some months and a charge in others.

Residential customers using other suppliers in Ameren paid about 2.43¢/kWh more when compared to the utility’s price to compare and about 3.05¢/kWh more when including the adjustment.

On the whole, the report said that residential customers with their own suppliers in ComEd paid around $8.23 million more per month in the 12 months through May compared to the utility price to compare.

In the individual 12 months, residential customers paid marginally more than the price to compare 11 times, inclusive of the adjustment.

The monthly negative difference ranged from 0.358¢/kWh to 2.821¢/kWh. May residential pricing from alternative suppliers was 3.491¢/kWh better than the price to beat.

Over 12 of the past 15 years, residential customers in Com Ed choosing their own supplier paid more than the price to beat by a range of a fraction of a cent per kilowatt hour to close to 3¢/kWh, inclusive of the adjustment.

The Illinois Citizens Utility Board said in June that in the current market, “the regulated utility (ComEd) is probably your best choice.”

Since 2015, Illinois consumers have lost more than $1 billion to alternative electric suppliers, said the board, a consumer advocacy group created by the state legislature.

“ComEd’s supply price is often the lowest option,” the board advised.

Supplier mc² told its customers in ComEd early this year that “some estimates suggest annual electric costs for average-use homes could be hundreds of dollars high than pre-2025 levels.”

The price comparison trend for residential customers on the Ameren system is similar to that of ComEd. The commission’s report said that for the 12 months ending in May, residential customers with alternate suppliers in Ameren paid more than the price to compare 10 times, including the adjustment.

The monthly negative difference ranged from 0.202¢ to 8.999¢/kWh.

As with residential alternative suppliers, interest in municipal aggregation plans also appears to be waning.

Illinois passed a law to allow for towns and counties to aggregate electrical load in 2010. While more than 750 communities adopted such plans for residential and small commercial loads, the report said that number of municipal aggregation programs in the state has declined over the last decade.

About half of the towns and counties in ComEd are still active in aggregation after their voters first passed a referendum. In Ameren, the proportion exceeds two-thirds.