Ameren Illinois Rate Selection Guide
Ameren Illinois serves 1.2M electric and 813K gas customers across central and southern Illinois (outside the Chicago metro). Full Smart Meter (AMI) deployment, Green Button Connect via PlugInIllinois.org integration, and full EDI for retail electric suppliers (RES) and alternative gas suppliers (AGS).
Ameren Illinois Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| DS-1 | Commercial - DS-1 | See tariff | Small General Service: <25 kW |
| DS-3 | Commercial - DS-3 | See tariff | General Service: 25-1,000 kW |
| DS-4 | Industrial - DS-4 | See tariff | Primary Service: 1-10 MW |
| DS-5 | Industrial - DS-5 | See tariff | Transmission Service: >10 MW |
| BEV | EV - BEV | See tariff | Business EV Charging Pilot |
| GDS-2 | Commercial - GDS-2 | See tariff | Small/Medium Gas Service |
| GDS-4 | Industrial - GDS-4 | See tariff | Large Gas Service / Transport |
Market Overview
Illinois is fully deregulated for electric and gas supply. Ameren Illinois is the regulated delivery utility; default supply procured via competitive bid. Customers shop generation from licensed Retail Electric Suppliers (RES) and Alternative Gas Suppliers (AGS) on PlugInIllinois.org. The default utility continues delivery and billing for non-shopping customers.
Need to pull your actual usage data to compare rates? See the Ameren Illinois Data Access Guide →
Current Rate Schedules
Ameren Illinois rates are filed with the IL PUC and updated periodically through rate cases or rider mechanisms. C&I customers face demand charges that scale with load and voltage level. TOU options available for many rate classes.
Effective: January 1, 2026 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| DS-1 | commercial | Small General Service: <25 kW | Customer charge plus tiered energy. No demand component. | — |
| DS-2 | commercial | General Service Non-Demand | Customer charge plus per-kWh delivery. Supply from RES or default bid. | — |
| DS-3 | commercial | General Service: 25-1,000 kW | Customer charge, billing demand (30-min peak), and energy. Optional TOU rider. | — |
| DS-4 | industrial | Primary Service: 1-10 MW | Primary voltage delivery with TOU energy and two-part demand. | — |
| DS-5 | industrial | Transmission Service: >10 MW | Transmission voltage with lowest delivery charges; customer provides downstream substation. | — |
| BEV | ev | Business EV Charging Pilot | Reduced demand charges for first 5 years to support EV infrastructure. | — |
Rate Recommendations by Use Case
Small Business
Small commercial with demand under 50-100 kW - retail, restaurants, small offices.
Demand charges may be modest at this scale. Focus on energy efficiency and rebate programs for fast payback.
- Install occupancy sensors and LED lighting
- Use smart thermostats with after-hours scheduling
- Apply for Ameren small business efficiency rebates
- Monitor demand monthly
Mid-Size Commercial 50-999 kW
Office buildings, grocery stores, shopping centers.
Demand charges become significant. Real-time demand monitoring is essential. TOU rate analysis and supplier shopping yield substantial savings.
- Install real-time demand monitoring
- Stagger HVAC unit startups by 10-15 minutes
- Evaluate TOU rate vs flat rate
- Enroll in commercial demand response
- Consider thermal energy storage
Large Industrial 1,000+ kW
Manufacturing plants, data centers, and heavy industrial operations.
Take service at highest practical voltage. Evaluate interruptible service, hourly pricing, and PJM capacity revenue.
- Take service at the highest voltage level feasible
- Maintain load factor above 70%
- Evaluate interruptible service or capacity bidding
- Install power factor correction
- Consider hourly pricing if you have dispatch capability
EV Fleet
Fleet depots, DC fast charging hubs, public charging operators.
EV-specific tariffs provide demand-charge mitigation in first 3-5 years. Off-peak overnight energy supports economical fleet charging.
- Schedule fleet charging during off-peak overnight hours
- Apply for utility EV make-ready infrastructure incentives
- Use managed-charging software to avoid coincident peaks
- Take the dedicated EV tariff
Historical Rate Trends
Ameren Illinois rates have increased moderately through formula rate plan updates, fuel cost adjustments, and PJM capacity riders. Annual increases ranged 2-8% with occasional decreases when gas prices retreat.
April 1, 2022
Annual rate adjustment reflecting elevated natural gas prices and capital investment in grid reliability.
+5.4%January 1, 2023
Base rate increase approved by IL PUC for distribution upgrades and grid resiliency.
+4.1%September 1, 2023
Fuel cost adjustment decrease as natural gas prices moderated.
-1.6%June 1, 2024
PJM capacity auction pass-through plus grid modernization investment.
+5.8%April 1, 2025
Formula rate plan update; includes EV infrastructure and decarbonization compliance costs.
+3.2%January 1, 2026
Annual base rate adjustment. Continued grid hardening and clean energy integration.
+2.9%Overall trend: Ameren Illinois rates have increased at roughly 3-6% annually over the past five years, driven by capital investment in grid modernization and clean energy compliance. Supply costs are more volatile due to PJM wholesale market exposure.
Next expected change: April 2026 (annual rate rider adjustment)
Cost Optimization Strategies
Bill savings opportunities fall into three buckets: supply procurement (deregulated), demand and TOU management, and efficiency. Combined approaches deliver highest savings for C&I customers with curtailable load.
Competitive Supply Procurement
For: All customer classes
In a deregulated market, the supply portion of your bill is fully negotiable. Solicit multiple bids; commercial customers typically save 5-15% vs default service via energy brokers.
Demand Management
For: C&I (50+ kW demand-billed)
Demand charges typically 30-50% of large C&I bills. Real-time demand monitoring with automated load shedding, stagger startups, thermal storage for cooling.
Time-of-Use Optimization
For: C&I with 20%+ shiftable load
Shifting load to off-peak yields largest energy savings. EV charging, water heating, HVAC pre-cooling are common levers.
Energy Efficiency & Rebates
For: All customer classes
Ameren and the Illinois energy efficiency administrator offer rebates for HVAC, lighting, controls, motors, and building automation.
To implement these strategies, you need your 15-minute interval data. Learn how to download Ameren Illinois interval data →
Deregulated Market Shopping
Illinois is fully deregulated for electricity supply. Ameren Illinois continues to deliver electricity regardless of supply choice. You can switch suppliers without service interruption.
How to Compare Ameren Illinois Suppliers
- 01Visit https://www.pluginillinois.org/offers.aspx - the state's official supplier comparison portal
- 02Compare licensed supplier offers to your utility's recent default supply cost
- 03Check if your municipality has a CCA or opt-out aggregation program
- 04For commercial customers (>100 kW), engage an energy broker to solicit bids
- 05Review contract length, early termination fees, auto-renewal terms
- 06Enroll directly with the chosen supplier
- 07Re-shop annually to maintain competitive pricing
Contract Terms for Ameren Illinois Supply Agreements
- Fixed-rate contracts typically 12-36 months for residential, longer for commercial
- Variable-rate plans fluctuate monthly and can spike during extreme weather
- Block-and-index contracts blend fixed portion with market-indexed pricing
- Early termination fees vary: $0 to $200 for residential, larger for commercial
- Auto-renewal is common - contracts revert to variable or higher fixed rate
- Renewable energy adders typically add $0.005-$0.02 per kWh
Common Pitfalls When Shopping Ameren Illinois Rates
- Introductory teaser rates that spike after 1-3 months
- Variable rate offers tied to wholesale markets can double in extreme events
- Door-to-door and telemarketing solicitations are often misleading
- Hidden monthly service charges and green energy adders
- Switching suppliers does NOT change your delivery charges
- Municipal aggregation enrollment is opt-out
- Cancellation requires advance notice (typically 30-60 days)
Frequently Asked Questions
How do I get 15-min interval data from Ameren Illinois?▾
Sign in at ameren.com - My Account - Energy Usage. Green Button Download exports CSV/XML for 24 months of 15-min electric (or daily gas) data. Ameren's AMI is 100% deployed across Illinois.
Does Ameren IL support Green Button Connect / OAuth API?▾
Yes. Ameren participates in Illinois's standardized data sharing program. Register as a third party at ameren.com/business/data-sharing; customer authorizes via OAuth.
Does Ameren support EDI for retail suppliers?▾
Yes - full EDI for both RES (electric) and AGS (gas). ANSI X.12: 814 (enrollment/drop), 810 (invoice), 820 (payment), 867 (meter reads). Connect via VAN.
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