Making Sense of Your Electric Bill

Your electric bill is generally divided into three categories: delivery charges, supply charges, and taxes.

Traditionally, delivery charges, which cover the cost of getting electricity to homes, have been set by the Illinois Commerce Commission (ICC) after 11-month rate cases. However, Ameren and ComEd now set those rates through a legislatively approved formula that is subject to ICC review.

The cost of the actual power (the supply charge) that ComEd and Ameren send to their customers is left up to the market.

Electricity usage is billed by the kilowatt-hour (kWh)—roughly enough power to clean a load of dishes in the dishwasher or run a window air conditioning unit for an hour. A customer’s previous and current meter readings are listed on the bill, along with the dates they were taken. The difference between the two readings is the electricity usage for the current billing period (typically a month).

A utility company should read a customer’s meter at least once every other month. If it doesn’t read your meter, your monthly bill will be estimated, and “E,” “EST,” or “ESTIMATED” will appear on it. That means your usage for that month was based on last year’s usage for the same month, adjusted for weather.

If the company doesn’t read your meter for two consecutive months, call the utility and find out why. Request an actual reading, or call CUB, at 1-800-669-5556, to learn how to read your own meter.

Glossary of Charges

(You may see some or all of these charges on your bill.)

Meter Information

Some of these charges may not be on your bill. The number next to each charge corresponds to the number on the sample bills in this fact sheet. If the names of charges differ between utilities, Ameren charges are labeled (A) and ComEd charges (C).

Read Dates. Billing period for which the meter was read.

Meter Number. Electric meter’s ID number.

Load Type. ComEd residential bills list “General Service.” Ameren bills do not have a section labeled “load type.”

Reading (or Read) Type. Electric usage is measured in kilowatt -hours (kWh).

Previous Meter Read. Previous month’s meter reading.

Present (Current) Meter Read. This month’s meter reading.

Read Difference (A); Difference (C). The difference between previous and past readings.

Multiplier. A factor applied to certain types of customers to determine usage. For most homes the multiplier is 1.

Usage. Electricity used in last billing period. (The difference between present and previous meter readings

Supply Charges

These rates, which take up a half to two-thirds of your bill, cover the cost of the electricity itself. Electricity prices are set by a market-based auction process. Under law, utilities are not allowed to profit off of this part of your bill.

Purchased Electric (A); Electricity Supply Charge (C). ComEd and Ameren are supposed to pass the energy costs on to customers with no markup. However, this charge may be slightly higher than the actual market price because it is adjusted for other costs, such as “line loss.” That’s when power traveling over the lines is lost as it gives off heat. Utilities have a summer and non summer rate for this charge.

Purchased Electricity Adjustment. Utilities can’t profit off the price of power, so this monthly adjustment, a credit or debit, balances any discrepancy between what the utility paid for power and what you paid in the energy charge.

Supply Cost Adjustment. Covers other administrative costs connected to procuring power. ComEd does not have a line item for this charge, but rolls it into the energy charge.

Transmission Service(s) Charge. Covers the costs of sending electricity from a power plant to your utility. A utility must get Federal Energy Regulatory Commission (FERC) approval to increase this charge. ComEd’s charge is 1.351 cents per kWh. Ameren’s charge is 0.914 cents per kWh.

To see these charges on a ComEd or Ameren bill, see the PDF version of this fact sheet.

Delivery Charges

These rates, which take up a third to a half of your bill, cover the cost of delivering power to homes, plus a profit for the utilities. When utilities ask the Illinois Commerce Commission (ICC) for a rate hike, they want to increase these rates.

Customer charge. Covers administrative costs of doing business, such as billing, postage, and building rental costs.

Meter Charge (A); Standard Metering Charge(C). Covers meter readings and other services, such as installing, maintaining, and testing meter equipment.

Distribution Delivery Charge (A); Distribution Facilities Charge (C). Covers the costs of maintaining equipment/wires, and other costs not recovered through the customer charge. (Ameren has summer/non-summer rates.)

Other Charges

EDT Cost Recovery (A); Illinois Electricity Distribution Charge (C). Recovers the Illinois Electricity Distribution Tax. This per kWh rate is the same for all customer classes.

Electric Environmental Adjustment (A); Environmental Cost Recovery Adj (C). Covers clean-up costs at former gas-manufacturing sites.

Renewable Energy Adjustment (A); Renewable Portfolio Standard (C). Previously, this was wrapped in the supply charge for electricity. It’s now a separate per kWh line item. ComEd customers pay 0.189 cents per kWh, and Ameren customers pay 0.196 cents per kWh. (Note: All electricity customers pay this, but temporarily customers with alternative suppliers will pay a slightly lower per kWh rate.

Clean Energy Assistance Charge (A); Zero Emission Standard (C). This is a subsidy for zero-carbon power generators. Exelon, the state’s biggest energy company, pushed for legislation to include this line item on all Ameren and ComEd power bills to provide more revenue to two of its nuclear power plants. To protect customers, CUB fought for major improvements in the bill. The final version of the legislation, the Future Energy Jobs Act, includes a historic boost in energy efficiency that will lower Illinois power bills by billions of dollars.

Energy Efficiency Demand Response (A); Energy Efficiency Programs (C). Under the Public Utilities Act, ComEd and Ameren recover the costs of energy efficiency and “demand-response” programs designed to help consumers save money. This per kWh charge covers programs such as air-conditioner cycling, appliance recycling, and Hourly Pricing. (Learn more at

Franchise cost. Some cities require a utility to pay a fee in exchange for the right to deliver electricity to them. Utilities recover such costs from customers in those towns.

Illinois state electricity excise tax (A); State tax (C). It’s a third of-a-cent per kWh.

Municipal tax. State law caps the utility tax that cities can impose. The utility collects the money (less than a penny per kWh) and forwards it to the municipality.

What your Electric Utility Charges

Ameren (1-800-755-5000)

Note: The space heat rates are NOT applicable to new customers.

Customer Charge*:


Meter Charge:


Energy Charge Non-summer (October-May):


Energy Charge Summer (June-September):


Distribution Charge:





First 800 kWh used: 5.038¢/kWh;  Usage over 800 kWh: 4.379¢/kWh.




Summer: 4.581¢/kWh

First 800 kWh used: 2.681¢/kWh; Usage over 800 kWh: 1.425¢/kWh

ComEd (1-800-334-7661)

Customer Charge*:



Meter Charge*:


Energy Charge Non-summer:


Energy Charge Summer:


Distribution Charge:

$10.84/month for single-family homes and buildings with two units ($12.61 space heat customers)
$7.68/month for buildings with three or more units ($8.39 space heat customers)








Non-space heat:
3.174¢/kWh for single-family,
2.535¢/kWh for multi-family

Space heat:
1.521¢/kWh for single-family, 1.428¢/kWh for multi-family

*Customer charge listed may include small fees to subsidize heating costs for low-income consumers; to develop renewable energy and clean-coal technology, to recover the costs of real-time pricing programs, which allow homes to pay an hourly rate for power; to cover utility billing costs associated with alternative retail energy suppliers; and an uncollectibles charge.