Breaking down the utility charges on your residential bill

Ameren Illinois

For ease of comparison, we list the Price to Compare before we break down the charges on your utility bill. Items A, B and C below reflect the order in which they appear on your Ameren Illinois bill. When you select service from a retail electric supplier, the Ameren Electric Supply and Transmission Services Charge (items B and C below) will be replaced with the charges from your new retail electric supplier. Currently, most suppliers will place their charges on your Ameren Illinois bill and some suppliers will send you a bill directly (containing Ameren Illinois' delivery service charges as well as the supplier's supply and transmission charges).

Price to Compare = Electric Supply Charges + Transmission Service Charge

Combining the electric supply charges and the transmission service charge results in the current Ameren Illinois Price to Compare, which is effective October 2011 through May 2012. Electric supply charges for June 2012 - May 2013 will not be determined until May 2012.

Residential Non-Space Heating
Price to Compare (in cents per kWh)

Ameren Illinois Rate Zone*	Non-Summer (October 2011 – May 2012)
Rate Zone I	6.685
Rate Zone I, Metro East (former UE) First 800kWh	6.685
Rate Zone I, Metro East (former UE) Usage above 800kWh	2.652
Rate Zone II First 800kWh	6.636
Rate Zone II Usage above 800kWh	4.468
Rate Zone III	6.368

Residential Space Heating (October 2011 – May 2012)
Price to Compare (in cents per kWh)

Ameren Illinois Rate Zone	First 800kWh	Usage above 800kWh
Rate Zone I	6.685	4.062
Rate Zone III	6.368	2.516

*Rate Zone I = previously AmerenCIPS
Rate Zone II = previously AmerenCILCO
Rate Zone III = previously AmerenIP

If you are using more than 800 kWh of electricity during the non-summer months, your price to compare depends on your usage and includes the rate for electricity consumed below 800kWh, the rate for electricity consumed above 800kWh, as well as the transmission service charge. For example, if you are an Ameren Illinois Rate Zone II customer using 900kWh during a non-summer month, your price to compare is 6.395 cents per kWh and if you are using 1200 kWh during a non-summer month, your price to compare is 5.914 cents per kWh.

If you are currently on the utility's rate for residences that had been served under the space heat or all-electric rate program prior to 2007, your price to compare depends on your usage and includes the rate for electricity consumed below 800kWh, the rate for electricity consumed above 800kWh, as well as the transmission service charge. For example, if you are an Ameren Illinois Rate Zone III customer using 900kWh during a non-summer month, your price to compare is 5.94 cents per kWh and if you are using 1200 kWh during a non-summer month, your price to compare is 5.084 cents per kWh.

A. Delivery Service Charges

You will pay the charges to deliver the electric supply from the transmission system to your home regardless of whether you purchase your electric supply from Ameren Illinois or a Retail Electric Supplier. On your Ameren bill, these charges are listed as DS or Delivery Service charges.

B. Electric Supply Charges

The electric supply charge is the price you pay per kWh for the amount of electricity you use in your home. The price of electric supply is determined by your choice of supplier, whether it be a Retail Electric Supplier or the electric utility. The Ameren Illinois rate for the electric supply during the summer months (June through September) is different from the utility rate during the non-summer months (October through May). In most cases, the Ameren Illinois rate for electric supply during the non-summer months (October – May) is lower if you use more than 800 kWh per month during the non-summer months.

Ameren Illinois Rate Zone	Non-Summer (October 2011 – May 2012) First 800kWh	Non-Summer (October 2011 – May 2012) Usage above 800kWh
Rate Zone I	6.057 cents per kWh	6.057 cents per kWh
Rate Zone I, Metro East (former UE)	6.057 cents per kWh	2.024 cents per kWh
Rate Zone II	6.020 cents per kWh	3.852 cents per kWh
Rate Zone III	5.733 cents per kWh	5.733 cents per kWh

Over the course of a year, your average utility rate per kWh is likely somewhere between the summer rate and the non-summer rate. Whether your average electricity supply charge for a 12-month period is closer to the summer rate or closer to the non-summer rate depends on how much electricity you use and during which months you use it. Please take a look at your electric bill or log in to your Ameren Illinois account here to see how much electricity you typically use over the course of a year and when you use it.

Attention Electric Space Heating Customers

If you are using electricity to heat your home and your home was served under the utility's space heating or all-electric rate prior to 2007, your rate for electricity consumed above 800 kWh is discounted as shown in the chart below. Also, while the chart below shows that there is no special electric space heating rate for Rate Zone I, Metro East (former UE) customers and Rate Zone II customers, please keep in mind that there are lower rates for usage above 800 kWh during the non-summer months for all of the residential Ameren Illinois customers in those service territories. The chart above shows those rates.

Non-Summer (October 2011 – May 2012)

Ameren Illinois Rate Zone	First 800kWh	Usage above 800kWh
Rate Zone I	6.057 cents per kWh	3.434 cents per kWh
Rate Zone III	5.733 cents per kWh	1.881 cents per kWh

The Electric Supply charge section on your Ameren Illinois bill includes a Supply Cost Adjustment, shown as "Rider PER Supply Cost Adj." The Supply Cost Adjustment is designed to allow the utility to recover costs associated with procurement, working capital and uncollectible charges. While there are very small monthly changes to the Supply Cost Adjustment on your Ameren Illinois bill, the Supply Cost Adjustment is largely a fixed charge that changes only when the ICC makes changes to Ameren Illinois' delivery service rates. The currently effective fixed Supply Cost Adjustment is at 0.143 cents per kWh for Ameren Illinois Rate Zone I customers, 0.132 cents per kWh for Ameren Illinois Rate Zone II customers, and 0.149 cents per kWh for Ameren Illinois Rate Zone III customers. When calculating the utility's electric supply price for Ameren Illinois' Price to Compare, we do include the fixed portion of the Supply Cost Adjustment.

You will also notice on your bill a monthly "Purchased Electricity Adjustment" that causes the electric supply charges to fluctuate above or below the established electric supply rate from one month to the next. The purpose of the Purchased Electric Adjustment is to "true-up" any difference (over or under) between what Ameren Illinois previously paid to acquire electric supply and what Ameren Illinois previously charged its customers for that electric supply. When calculating the utility's electric supply price for Ameren Illinois' Price to Compare, we do not include a value for the Purchased Electricity Adjustment. You will not be charged for the Purchased Electricity Adjustment when you switch to a Retail Electricity Supplier.

C. Transmission Service Charge

Also included in the Electric Supply Section on your Ameren Illinois bill is the Transmission Service Charge. The transmission service charge is designed to allow the utility to recover costs associated with transmission service. The transmission charge is set annually by the Federal Energy Regulatory Commission (FERC). However, the charge on your bill varies from month-to-month similar to the Purchased Electricity Adjustment to "true-up" any discrepancy (over or under) due to timing. These month-to-month variations should trend towards zero over the course of a year. For purposes of calculating Ameren Illinois' Price to Compare we do not include the monthly fluctuations but only the FERC approved transmission service charge. The currently effective transmission service charge that we include in the Ameren Illinois Price to Compare is 0.4853 cents per kWh for Ameren Illinois Rate Zone I customers, 0.4843 cents per kWh for Ameren Illinois Rate Zone II customers, and 0.4859 cents per kWh for Ameren Illinois Rate Zone III customers.