Notwithstanding section 3302 of title 31 and section 825s of this title, all funds collected by the Southwestern Power Administration that are applicable to the repayment of the annual expenses of this account in this and subsequent fiscal years shall be credited to this account as discretionary offsetting collections for the sole purpose of funding such expenses, with such funds remaining available until expended: Provided further, That for purposes of this appropriation, annual expenses means expenditures that are generally recovered in the same year that they are incurred (excluding purchase power and wheeling expenses).