; or (B) the Secretary finds that significantly less than the full amount of funding authorized for programs under this Act has been appropriated, resulting in substantial limitation to or delay of the technology advancement program elements of this Act; or (2) after the end of a clean electricity standard compliance period, if the clean electricity requirement is not enforced for the compliance period. (c) Clean air act authorities Except as provided in this section, neither a State nor the Administrator of the Environmental Protection Agency may enforce any emission limitation for carbon dioxide emissions from fossil fuel-fired electric power generating units established under title I of the of the Clean Air Act ( 42 U.S.C. 7401 et seq.). (d) Definitions In this section: (1) Compliance period The term compliance period has the meaning given such term in section 611(k)(1) of the Public Utility Regulatory Policies Act of 1978. (2) Program trigger date The term program trigger date has the meaning given such term in section 611(k)(2) of the Public Utility Regulatory Policies Act of 1978.