Creates the Advanced Technology Leadership Act. Sets forth findings. Defines terms. Sets forth provisions concerning the qualification of credits under the Act. Provides that, beginning calendar year 2027, each covered data center shall self-generate or procure and then retire eligible energy attribute certificates equal to the certain percentages of the covered data center's annual State electricity consumption. Provides that a covered data center's compliance requirement shall be otherwise met by retirements of eligible energy attribute certificates produced by eligible energy facilities that are physically interconnected and located in the applicable grid region. Requires a covered data center to retire eligible energy attribute certificates that are matched on an hourly basis to the certain percentages of the covered data center's total State electricity consumption for the following compliance years. Provides that covered data centers shall account for and comply with the Act exclusively through the retirement of eligible energy attribute certificates. Requires the Illinois Power Agency to, on an ongoing basis, identify facilities that meet the definition of covered data center. Provides that the Agency shall strive to minimize administrative expenses in the implementation and regulation of activities related to the Act. Makes other changes. Effective immediately.