Synopsis As Introduced Amends the Public Utilities Act. Provides that the Illinois Commerce Commission shall quarterly review the price of any zero emission credits procured by the Illinois Power Agency to ensure no more than the unrecovered costs of the plants based on market sales and pricing is recovered. Provides that if the plant shows a profit for more than one year, the zero emission credit program shall be rebid and the Illinois Power Agency shall have the authority to expand the definition to include additional Illinois-based zero emission generation sources as eligible for the program. Provides that the Commission shall ensure any qualifying nuclear plant is not receiving excessive earnings through its zero emission credit compensation, and if a plant is found to have received excessive earnings due to the zero emission credit pricing, that plant shall have its zero emission credit qualification revoked. Provides that nothing prevents the Commission from initiating a docketed proceeding to reconcile zero emission credit payments with allowed costs. Effective immediately or on the date certain provisions of Public Act 99-906 take effect, whichever is later.