the utility owns or operates any existing electric powerplant in which natural gas was used as a primary energy source at any time during the 1-year period ending on August 13, 1981, and

the utility plans to use natural gas as a primary energy source in any electric powerplant.

submit, within 1 year after August 13, 1981, and have approved by the Secretary, a conservation plan which meets the requirements of subsection (c); and

implement such plan during the 5-year period beginning on the date of the initial approval of such plan.

Any conservation plan under this section shall set forth means determined by the utility to achieve conservation of electric energy not later than the 5th year after its initial approval at a level, measured on an annual basis, at least equal to 10 percent of the electric energy output of that utility during the most recent 4 calendar quarters ending prior to August 13, 1981, which is attributable to natural gas.

Any such plan may set forth a program for the use of renewable energy sources (other than hydroelectric power).

Any such plan shall contain procedures to permit the amounts expended by such utility in developing and implementing the plan to be recovered in a manner specified by the appropriate State regulatory authority (or by the utility in the case of a nonregulated utility).

The Secretary shall, by order, approve or disapprove any conservation plan proposed under this subsection ¹ by an electric utility within 120 days after its submission. The Secretary shall approve any such proposed plan unless the Secretary finds that such plan does not meet the requirements of subsection (c) and states in writing the reasons therefor.

In the event the Secretary disapproves under paragraph (1) the plan originally submitted, the Secretary shall provide a reasonable period of time for resubmission.

An electric utility may amend any approved plan, except that the plan as amended shall be subject to approval in accordance with paragraph (1).