Martinsville Electric Aggregation

Martinsville’s municipal electric aggregation buys electricity from Constellation NewEnergy, Inc. at 11.538¢ per kWh, fixed through May 31, 2027. That’s 1.1¢ above Ameren’s current price to compare of 10.441¢.

11.538¢
Aggregation rate
per kWh, fixed
+1.1¢
vs. Ameren default
10.441¢ price to compare
Constellation NewEnergy, Inc.
Supplier
30 Illinois programs
May 2027
Contract ends
May 31, 2027

How Martinsville’s Rate Compares With Ameren

Martinsville’s 11.538¢ rate is 1.1¢ above Ameren’s price to compare of 10.441¢ for the first 800 kWh a month (8.262¢ above that), which applies from Oct 1, 2026 through May 31, 2027. On 1,000 kWh in a month, that’s about $15.33 more for supply.

Martinsville aggregation rate compared with the Ameren Illinois price to compare
Supply pricePer kWhOn 1,000 kWh
Martinsville aggregation (Constellation NewEnergy, Inc.)11.538¢$115.38
Ameren Illinois price to compare10.441¢*$100.05
Difference+1.1¢+$15.33

* Ameren’s price is 10.441¢ for the first 800 kWh a month and 8.262¢ after that; the 1,000 kWh figure uses both.

Ameren’s price to compare changes several times a year. It was 11.326¢ from June 1 to September 30, 2026, when Martinsville’s rate was 0.21¢ above it. Among the 260 fixed-rate aggregation programs in Ameren Illinois territory, Martinsville’s is the 105th lowest.

These are supply prices only. Ameren Illinois still delivers the power and bills its delivery charges either way.

About Martinsville’s Program

Constellation NewEnergy, Inc. supplies 30 of the 418 active Illinois aggregation programs, at a median fixed rate of 11.695¢.

Facts about Martinsville’s aggregation program
CommunityCity of Martinsville, Clark County
Households532 occupied homes (Census 2020-2024 ACS 5-year)
SupplierConstellation NewEnergy, Inc.
Delivery utilityAmeren Illinois
Contract endsMay 31, 2027
EnrollmentOpt-out: residents are enrolled unless they return the opt-out notice
ReferendumApril 2013
ICC list entry“Martinsville | Constellation NewEnergy, Inc. | 11.538 | May 31, 2027”

How to Opt Out or Leave

Illinois rules are the same in every aggregation community. In the Illinois Commerce Commission’s words:

  • Opting out. “The chosen supplier will send opt-out notices to all residents and eligible small businesses within the municipality or county. You will need to fill out and return the opt-out notice in order to be excluded from the aggregation program.”
  • Leaving later. “Suppliers are prohibited from applying early termination fees or penalties to residential and small commercial retail customers who terminate their contracts and switch to a different supplier or go back to the utility's service.”
  • If you already buy from a supplier. “If you are enrolled with a supplier or the utility's residential real-time program at the time the opt-out notices are being sent out, you will likely not be included in your municipality's or county's aggregation program.”

Source: Municipal Aggregation, Plug In Illinois (Illinois Commerce Commission). More on how Illinois aggregation works on the Illinois aggregation page.

Other Constellation NewEnergy, Inc. Programs in Ameren Illinois Territory

No other Clark County community has an active aggregation program, so here are the Constellation NewEnergy, Inc. programs closest to Martinsville’s rate.

Other Constellation NewEnergy, Inc. Programs in Ameren Illinois Territory
CommunitySupplierRatevs. defaultEnds
Manito Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Kilbourne Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Topeka Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Easton Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Forest City Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Mason County Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Mason City Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Havana Constellation NewEnergy, Inc. 11.538¢ +1.1¢ May 2027
Tilton Constellation NewEnergy, Inc. 11.595¢ +1.15¢ May 2027
Oakwood Constellation NewEnergy, Inc. 11.595¢ +1.15¢ May 2027
418
Every Active Illinois Aggregation Program Suppliers, rates and contract dates, compared with ComEd and Ameren →

Frequently Asked Questions

Who supplies electricity in Martinsville’s aggregation program?

Constellation NewEnergy, Inc., under a contract that runs through May 31, 2027, according to the Illinois Commerce Commission’s municipal aggregation list (checked November 2, 2026). Ameren Illinois still delivers the power.

What is Martinsville’s electric aggregation rate?

11.538¢ per kWh, fixed until May 31, 2027. That is the supply price only; Ameren Illinois’s delivery charges are billed separately on the same bill.

Is Martinsville’s aggregation rate lower than Ameren’s?

No. Martinsville’s 11.538¢ rate is 1.1¢ above Ameren’s price to compare of 10.441¢ for the first 800 kWh a month (8.262¢ above that), which applies from Oct 1, 2026 through May 31, 2027. Ameren’s price was 11.326¢ from Jun 1 to Sep 30, 2026, when Martinsville’s rate was 0.21¢ above it.

How do I opt out of Martinsville’s electric aggregation?

Return the opt-out notice. The Illinois Commerce Commission says: “The chosen supplier will send opt-out notices to all residents and eligible small businesses within the municipality or county. You will need to fill out and return the opt-out notice in order to be excluded from the aggregation program.”

Is there a fee to leave Martinsville’s aggregation program?

No. The Illinois Commerce Commission says: “Suppliers are prohibited from applying early termination fees or penalties to residential and small commercial retail customers who terminate their contracts and switch to a different supplier or go back to the utility's service.”

When did Martinsville approve electric aggregation?

The ICC list gives Martinsville’s aggregation referendum date as April 2013. In Illinois, an opt-out program needs voters to approve it in a referendum.

Sources