If your Illinois business is in northern Illinois (ComEd) or central/southern Illinois (Ameren), you're in different utility territories with different grid operators, different rate structures, and different competitive supplier markets. Understanding the differences helps with procurement strategy.
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Side-by-Side Comparison
| Factor | Option A | Option B |
|---|---|---|
| Service territory | Chicago and northern Illinois | Central and southern Illinois |
| Grid operator | PJM | MISO |
| Typical commercial rates | Higher (urban/suburban congestion) | Lower (less congested) |
| ARES competition | Very competitive (40+) | Moderate competition |
| Utility structure | Investor-owned (Exelon) | Investor-owned (Ameren) |
ComEd Territory
ComEd serves northern Illinois including Chicago — the largest commercial electricity market in the Midwest. The PJM grid governs wholesale pricing. Chicago's urban density creates transmission congestion that adds to commercial rates. 40+ ARES providers actively compete for ComEd commercial accounts, making it a highly competitive procurement market.
Ameren Illinois Territory
Ameren Illinois serves central and southern Illinois under MISO — a different grid operator than ComEd's PJM. MISO capacity charges and ancillary structures differ from PJM, affecting commercial pricing. The supplier market is somewhat less competitive than ComEd territory, but ARES alternatives are available for commercial accounts.
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Procurement Strategy Differences
In ComEd territory, competition among 40+ suppliers is intense — a broker process yields strong competing bids. In Ameren territory, the supplier pool is smaller but competition is still meaningful. Both markets benefit from a formal broker process over direct negotiation with a single supplier.
Frequently Asked Questions
Can the same ARES supplier serve both ComEd and Ameren accounts?
Many large ARES providers are licensed in both territories. However, they price each territory separately and may not be equally competitive in both.
Are ComEd or Ameren rates higher?
ComEd commercial rates are typically higher due to Chicago urban congestion and higher capacity costs in PJM. Ameren Illinois is generally lower-cost on a per-kWh basis.
Is natural gas also deregulated in Illinois?
Yes. Nicor Gas (northern IL), Peoples Gas (Chicago), and other LDCs serve as distribution utilities while ARES can provide competitive gas supply.