alternative method of compliance
(20) The term “alternative method of compliance” means a method of compliance in accordance with one or more of the following authorities: (A) a substitution plan submitted and approved in accordance with subsections 7651c(b) and (c) of this title; (B) a Phase I extension plan approved by the Administrator under section 7651c(d) of this title , using qualifying phase I technology as determined by the Administrator in accordance with that section; or (C) repowering with a qualifying clean coal technology under section 7651h of this title .