IL HB4085

Amends the Environmental Protection Act to establish CO2e and copollutant emission reduction deadlines for electric generating units (EGUs) and large greenhouse gas-emitting units, with different timelines based on fuel type and ownership (public vs. private).

Coal-fired units not publicly owned must reduce emissions to zero by January 1, 2030; publicly owned coal units must achieve zero emissions by December 31, 2045, with a 45% reduction requirement by January 1, 2035.

Natural gas-fired units must reduce emissions to zero by January 1, 2045, with stricter timelines (2030-2040) for units in or near environmental justice communities, and restrictions on operation to 6 hours per day average after 2035 for non-compliant units.

Allows owners and operators to petition the Illinois Commerce Commission for waivers if compliance would threaten electricity supply reliability or create significant economic hardship for electricity users; the Commission can grant waivers for specified periods.

Requires annual emissions reporting by the Agency and every-5-year joint reports by the Environmental Protection Agency, Illinois Power Agency, and Illinois Commerce Commission to assess progress toward renewable energy goals and resource adequacy, with provisions for reliability mitigation plans if shortfalls are identified.