Several factors influence what customers ultimately pay for electricity, including fuel costs, weather, and regional supply and demand. The summer often presents additional challenges as usage increases because appliances and equipment work harder when temperatures rise.
Rising electric supply prices over the last several years are indicative of growing demand for electricity and constraints in available supply on the Midwest power grid. It’s important to know that Ameren Illinois is a delivery-only utility, meaning we don’t produce or generate electricity; we simply deliver it (through poles and wires) to homes and businesses. Therefore, Ameren Illinois doesn’t control or profit from electricity market prices, despite those costs being included on the Ameren Illinois monthly bill.
There are three main components to the energy bill – the delivery charge (think poles, wires, transformers, meters), power supply (the actual electric current that flows through the delivery system), and taxes/fees.
- The largest component is the power supply, or the cost of electricity itself. Ameren Illinois does not own generation or generate power; it is procured and priced by a state agency (Illinois Power Agency) and the regional grid operator (MISO) for Ameren Illinois to deliver. The cost of electricity supply accounts for about half of a typical customer's monthly electric bill amount. Ameren Illinois highlights the generator’s supply costs on the energy bill and passes those costs to customers, dollar for dollar, without markup.
- Another component is the delivery charge, which covers the costs of Ameren Illinois' wires and poles, technology and operating systems, maintenance and modernization of the grid, and the people who do the work. As a delivery-only utility, Ameren Illinois earns a profit on energy delivery as set each year in rates reviewed and approved by the Illinois Commerce Commission.
- The final component includes taxes and mandated program costs and fees. This component represents a growing share of the electric bill.
Electricity supply prices are made up of two key components: energy and capacity. A simple way to think about the difference is a faucet and a bucket. Capacity is like the size of the faucet—it determines how much water can flow when you turn it on. Energy is the water that actually flows into the bucket over time. Customers pay for both: the electricity they use day to day (energy) and the assurance that enough power will be available when demand is highest (capacity).*
The Illinois Power Agency (IPA) procures electricity and a portion of electric capacity for residential and small commercial customers who have not switched to an alternative supplier to meet forecasted usage throughout the year. Capacity is acquired to ensure enough power is available when usage peaks, such as on extremely hot summer days. The IPA attempts to secure as much capacity as possible in advance. The remaining capacity is procured by MISO through its annual capacity auction.
The total supply price includes electricity costs (procured by the IPA) and capacity costs (procured by the IPA and MISO). Ameren Illinois enters into contracts at the prices secured through the IPA and MISO and passes those supply costs to customers dollar for dollar, with no markup or profit.
- By law, a state agency negotiates electric supply contracts for Ameren Illinois.
- When the regional electric grid operator for the Midwest held its annual generation capacity auction, it showed lower available surplus capacity for the summer months, resulting in new summer capacity prices over spring prices.
- Ameren Illinois does not profit from energy supply. Supply costs are passed on to customers directly, dollar for dollar, with no markup.
- The answer depends on the terms of the agreement between the customer and their retail supplier, which Ameren Illinois does not have knowledge of. Approximately 42% of Ameren Illinois’ customers receive their power supply from a third-party retail supplier.
- Neither Ameren Illinois nor the Illinois Power Agency (IPA) establishes prices for retail suppliers.
- Ameren Illinois supports electric supply choice but strongly encourages customers to know the Price to Compare and ensure they are paying the lowest possible price for their supply.
- Customers can visit the Illinois Commerce Commission website at Plugin Illinois to learn more about electric choice and compare supply options. to learn more about electric choice and compare supply options.
Yes. To help our customers manage rising energy costs, Ameren Illinois helps facilitate access to bill assistance programs, bill payment grants, and flexible payment arrangements.
Ameren Illinois facilitated distribution of $103 million in financial assistance in 2025 and $32 million through March of this year.
Information on financial assistance is available at AmerenIllinois.com/Assistance.