that the annual quantity of energy produced by the Boulder Canyon Project is predicted to be less than 3,600,000 MWh, the Administrator shall reduce rates for each project use and firm electric service customer of the Boulder Canyon Project in each monthly invoice for firm electric service until such time as the expected annual energy production returns to levels equal to or greater than 3,600,000 MWh. (3) Parker-Davis project If a notification under subsection (a)(1) indicates that the annual quantity of energy produced by the Parker-Davis Project is expected to be less than 1,400,000 MWh, the Administrator shall reduce rates for each project use and firm electric service customer of the Parker-Davis Project in each monthly invoice for project use and firm electric service until such time as the expected annual energy production returns to levels equal to or greater than 1,400,000 MWh. (c) Rate reduction (1) In general For purposes of calculating a rate reduction required under subsection (b), the Administrator shall reduce rates for each project use and firm electric service customer in accordance with the principles described in sections 2 and 3. (2) Limitation on rate reduction The Administrator may not reduce rates as required under subsection (b) by an aggregate amount greater than any unobligated balances associated with the projects described in subsection (a)(2). (d) Termination of effectiveness Subsections (a) through (c) shall cease to be effective on December 31, 2031. 5. Effect (a) Cost recovery Nothing in this Act preempts the obligations of the Administrator to set rates to recover costs as may be required by law. (b) Funding (1) In general Nothing in this Act authorizes additional appropriations for the Western Area Power Administration. (2) Use of existing funds The Administrator shall use any funds authorized and appropriated to the Western Area Power Administration on an annual basis to carry out the duties of the Administrator under this Act. (c) No retroactive rates Notwithstanding any other