; and (B) the construction of which is completed on or after the date of enactment of this section; or (2) an expansion of, or upgrade to, an interstate electric power transmission line (and any facilities necessary for the operation of such electric power transmission line) or an electric power transmission line that is located offshore (and any facilities necessary for the operation of such electric power transmission line) that— (A) increases the transmission capacity of such electric power transmission line by at least 500 megawatts; and (B) is completed on or after the date of enactment of this section. (c) Savings provision This section does not affect the authority of the Commission to approve the allocation of costs of transmission facilities other than transmission facilities of national significance. .