Creates the Data Center Energy Accountability Act. Provides that, beginning in compliance year 2028, each covered data center shall account for its annual electricity demand on an hourly basis by reporting the volume of generation that was consumed in each year, month, day, and hour. Requires each covered data center to also self-generate, or procure, and then retire eligible environmental attribute certificates equal to 100% of the covered data center's annual State electricity consumption. Provides that eligible environmental attribute certificates that are retired in order to comply with the Act must have been produced by electric generation facilities and batteries that have a commercial operation date that is no more than 7 years older than the compliance year for which the environmental attribute certificates are retired. Sets forth tracking and verification requirements for the Illinois Power Agency. Provides that environmental attribute certificates shall not be eligible under the Act if the retirement of the environmental attribute certificates would result in the double counting or double claiming of otherwise eligible energy. Provides that, upon interconnection, the owner of a covered data center shall be required to notify the Agency of its status as a regulated facility pursuant to the requirements of the Act. Provides that, if a covered data center is unable to meet the requirements of the Act for a given compliance year, a covered data center shall make an alternative investment payment for each megawatt-hour shortfall in the applicable year. Creates the Electron Accelerator Fund as a special fund in the State treasury, to be administered by the Agency. Sets forth requirements for the Fund. Provides that, if deemed appropriate by the Agency, the Agency shall file a utility disconnection proceeding with the Commission if a covered data center does not responsibly comply with the Act. Sets forth rulemaking abilities for the Agency. Amends the State Finance Act to make a conforming change. Effective immediately.