((a)) ** Permanent exemption due to lack of alternate fuel supply, site limitations, or environmental requirements**

((1)) After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a powerplant, the Secretary shall, by order, grant a permanent exemption under this subsection for the use of natural gas or petroleum, if he finds that the petitioner has demonstrated that despite diligent good faith efforts—

((A)) it is likely that an adequate and reliable supply of coal or other alternate fuels of the quality necessary to conform with design and operational requirements for use as a primary energy source will not be available to such powerplant at a cost (taking into account associated facilities for the transportation and use of such fuel) which, based upon the best practicable estimates, does not substantially exceed the cost, as determined by rule by the Secretary, of using imported petroleum as a primary energy source during the remaining useful life of the powerplant;

((B)) one or more site limitations exist which would not permit the operation of such a powerplant using coal or any other alternate fuel as a primary energy source; or

((C)) the prohibitions of part A could not be satisfied without violating applicable environmental requirements.

((2)) Notwithstanding the preceding provisions of this subsection, a powerplant which has been granted an exemption under subsection (g) may not be granted an exemption under this subsection.

((b)) ** Permanent exemption due to certain State or local requirements** After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a powerplant, the Secretary may, by order, grant a permanent exemption under this subsection, if he finds that the petitioner has demonstrated that—

((1)) with respect to the site of the powerplant, the operation of such a facility using coal or any other alternate fuel is infeasible because of a State or local requirement;

((2)) if such State or local requirement is under a building code or nuisance or zoning law, no other exemption under this part could be granted for such facility; and

((3)) the granting of the exemption would be in the public interest and would be consistent with the purposes of this chapter.

((c)) ** Permanent exemption for cogeneration** After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a cogeneration facility, the Secretary may, by order, grant a permanent exemption under this subsection, if he—

((1)) finds that the petitioner has demonstrated that economic and other benefits of cogeneration are unobtainable unless petroleum or natural gas, or both, are used in such facility, and

((2)) includes in the final order a statement of the basis for such finding.

((d)) ** Permanent exemption for certain fuel mixtures containing natural gas or petroleum**

((1)) After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a powerplant, the Secretary shall, by order, grant a permanent exemption under this subsection, if he finds that the petitioner has demonstrated that—

((A)) the powerplant uses, or proposes to use, a mixture of petroleum or natural gas and coal or another alternate fuel as a primary energy source; and

((B)) the amount of the petroleum or natural gas used in such mixture will not exceed the minimum percentage of the total Btu heat input of the primary energy sources of such powerplant needed to maintain reliability of operation of the unit consistent with maintaining a reasonable level of fuel efficiency, as determined in accordance with rules prescribed by the Secretary.

((2)) Repealed. , , .

((3)) The Secretary may authorize a higher percentage than that referred to in paragraph (1)(B) if he finds that the higher percentage of natural gas allowed would be mixed with synthetic fuels derived from municipal wastes or agricultural wastes and would encourage the use of alternate or new technologies which use renewable sources of energy.

((e)) ** Permanent exemption for emergency purposes** After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a powerplant, the Secretary shall, by order, grant a permanent exemption under this subsection, if he finds that the petitioner has demonstrated that such powerplant will be maintained and operated only for emergency purposes (as defined by rule by the Secretary).

((f)) ** Permanent exemption for peakload powerplants** After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a powerplant, the Secretary shall, by order, grant a permanent exemption under this subsection, if he finds that—

((1)) the powerplant is operated solely as a peakload powerplant;

((2)) a denial of such petition is likely to result in an impairment of reliability of service; and

((3))

((A)) modification of the powerplant to permit compliance with such prohibitions is technically infeasible; or

((B)) such modification would result in an unreasonable expense.

((g)) ** Permanent exemption for intermediate load powerplants**

((1)) After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A on the use of petroleum by a powerplant, the Secretary may, by order, grant a permanent exemption under this subsection, if he finds that the petitioner has demonstrated that—

((A)) the Administrator of the Environmental Protection Agency (or the appropriate State air pollution control agency) certifies to the Secretary that the use by such powerplant of coal or any available alternate fuel as a primary energy source will cause or contribute to a concentration, in an air quality control region or any area within such region, of a pollutant for which any national ambient air quality standard is or would be exceeded for such area;

((B)) such powerplant is to be operated only to replace no more than the equivalent capacity of existing electric powerplants—

((i)) which use natural gas or petroleum as a primary energy source,

((ii)) which are owned by the same person who is to operate such powerplant, and

((iii)) which, if they used coal as a primary energy source, would cause or contribute to such a concentration in such region;

((C)) such powerplant is and shall continue to be operated solely as an intermediate load powerplant;

((D)) the net fuel heat input rate for such powerplant will be maintained at or less than 9,500 Btu’s per kilowatt hour throughout the remaining useful life of the powerplant; and

((E)) the powerplant has the capability to use synthetic fuels derived from coal or other alternate fuel.

((2)) The Secretary shall, from time to time, review each exemption granted to a powerplant under this subsection, and shall terminate such exemption if he finds that there is available a supply of synthetic fuel derived from coal or other alternate fuel suitable for use as a primary energy source by such powerplant.

((h)) ** Permanent exemption for use of natural gas by certain powerplants with capacities of less than 250 million Btu’s per hour**

((1)) Subject to paragraph (2), after consideration of a petition (and comments thereon) for an exemption from any prohibition of part A for the use of natural gas by a powerplant, the Secretary shall, by order, grant a permanent exemption under this subsection for such use, if he finds that the petitioner has demonstrated that—

((A)) such powerplant has a design capability of consuming fuel (or any mixture thereof) at a fuel heat input rate of less than 250 million Btu’s per hour;

((B)) such powerplant was a baseload powerplant on ; and

((C)) such powerplant is not capable of consuming coal without—

((i)) substantial physical modification of the unit; or

((ii)) substantial reduction in the rated capacity of the unit (as determined by the Secretary).

((2)) An exemption under this subsection may only apply to the prohibitions under and prohibitions established by final rules or orders issued before .

((i)) ** Permanent exemption for use of LNG by certain powerplants** After consideration of a petition (and comments thereon) for an exemption from one or more of the prohibitions of part A for a powerplant, the Secretary shall, by order, grant a permanent exemption under this subsection for the use of liquefied natural gas if the Administrator of the Environmental Protection Agency (or the appropriate State air pollution control agency) has certified to the Secretary that the use of coal by such powerplant as a primary energy source will cause or contribute to a concentration, in an air quality control region or any area within such region, of a pollutant for which any national ambient air quality standard is or would be exceeded for such region or area and the use of coal would not comply with applicable environmental requirements.