Stands for Alternative Retail Electric Supplier. A non-utility who is approved by the Illinois Commerce Commission to sell electricity.

Stands for Alternative Gas Supplier. A non-utility who is approved by the Illinois Commerce Commission to sell natural gas.

The standard unit of electrical current. Often referred to as an amp.

The minimum amount of power that a buyer needs to meet their demands.

An independent marketer who sells energy to commercial and/or residential customers. Brokers are not part of a utility and often work with ARES and AGS suppliers.

Standard unit of measurement often seen on appliances that measures the heat of a fuel source.

The maximum amount of power that a system or subsystem can carry or produce at a specific moment. Capacity is typically measured in megawatts.

An additional charge that covers the difference between a customer's peak energy use and their normal use during the same billing cycle.

A conductor or a system of conductors through which electric current flows.

An agreed upon price between the seller and the buyer. The terms can be monthly, quarterly, yearly.