This bill, titled the Affordable, Reliable, Clean Energy Security Act of 2025, mandates that federal departments and agencies adopt specific definitions for the terms affordable, reliable, and clean energy. It defines affordable energy as a low-cost method of producing electricity, considering the full system cost of each generation source. Reliable energy is characterized as a source with an Effective Load Carrying Capability of 60 percent or greater, not subject to intermittent availability, and not impacted by routine weather conditions. Furthermore, the bill defines clean energy to include energy generated using sources listed in section 203(b) of the Energy Policy Act of 2005, nuclear reactors, and the combustion of hydrocarbons, including natural gas, provided they meet national ambient air quality standards under the Clean Air Act. Within 90 days of enactment, the Secretaries of Energy and Interior, along with the Administrator of the Environmental Protection Agency, must identify and publish all relevant regulations, grants, guidance, and policies. Subsequently, these agencies are directed to update these items to incorporate the new definitions and then submit a report to Congress detailing their implementation within 180 days.