We depend on the reliability of our Naperville electricity which also depends on the reliability of the electric power grid. That electric power grid is a vast network of power generators, transmission lines, and local distribution, where there is a requirement for perfect continuous balance of the electricity being generated and consumed throughout the grid.

The three major components of the electric power grid are:

• Local distribution networks, which in Naperville’s case are the underground cable and Smart Grid that are owned and operated by our Naperville Electric Utility to serve the customers who consume our electricity.

• High voltage transmission lines to bring distant generated electricity to the local distribution network. Naperville’s local distribution network connects to transmission lines at several locations in the city.

• Electric power generators, including power plants and utility scale solar, wind and other resources, typically located at a distance from the local distribution network.

All three components must operate reliably to “keep the lights on” in Naperville 24 hours a day, 365 days a year. Although IMEA claims to have an important role in reliability, its operational role is quite limited since IMEA relies primarily on contracts to supply our electricity needs. This list below outlines our “educated citizen” knowledge and understanding of the reliability issues and responsibilities:

• Rules, regulations, and planning for reliability of the electric power grid reliability are the responsibility of FERC, NERC, PJM, MISO, and other authorities.

• Naperville is responsible for the reliability of our local Naperville distribution network, including our electric utility leadership and staff and our investment in underground cable and Smart Grid technology.

• ComEd and Ameren-Illinois are responsible for the reliability of their transmission resources that IMEA uses to serve the IMEA members. PJM is responsible for the flow of electricity on the ComEd transmission system in northern Illinois, and MISO is responsible for the Ameren-Illinois transmission system in downstate Illinois.

• Load balancing authorities PJM and MISO are responsible for matching generation with consumption. They schedule and dispatch generators, including those that are used primarily for peak generation or reserve needs. Since Naperville is located in PJM, PJM is responsible for matching generation with our Naperville consumption, and the consumption of our ComEd neighbors too, in order to “keep the lights on”.

For further details, please see our pdf file document “Reliability of Naperville’s Electricity” and its links to other resources.