9.—(1) Subject to paragraphs (2) and (4) , the amount of electricity generated by a generating station which is to be regarded as having been generated from eligible renewable sources in any month is to be calculated by multiplying the renewable output of that generating station in that month by a proportion which is equal to the proportion which the net output of that generating station in that month bears to the gross output of that station in that month and for the purposes of this calculation–
(a)“the renewable output” is such amount as is obtained by deducting from the gross output of that generating station in that month the amount of electricity which has been generated from fossil fuel in that month; and
(b)“the net output” is such amount as is obtained by deducting from the gross output of that generating station in that month the input electricity of that generating station in that month.
(2) In the case of a generating station fuelled wholly or partly by biomass, 2 per cent of the electricity generated from biomass in any month shall be treated as having been generated from fossil fuel unless the operator of the generating station satisfies the Authority that during that month a lesser percentage of the energy content of the biomass derives from fossil fuel, in which case that lesser percentage shall be treated as having been generated from fossil fuel.
(3) In calculating “the renewable output” in the case of a generating station fuelled partly by fossil fuel and partly by another fuel or fuels the amount of electricity which has been generated from fossil fuel is to be determined according to the respective energy contents of the fuels used.
(4) Where the operator of a generating station satisfies the Authority that in any month the input electricity of the generating station does not exceed 0.5 per cent of its gross output, no input electricity shall be deducted from the gross output in calculating the net output of the generating station for that month and, accordingly, the net output shall be equal to the gross output in that month.
(5) In this article–
(a)“fossil fuel” has the meaning given to it by section 32 of the Act except that the expression also includes any substance which is derived directly or indirectly from fossil fuel (whether or not such substance is waste or a component of biomass);
(b)“gross output” means, in relation to any month, the total amount of electricity generated by a generating station in that month; and
(c)“input electricity” means, in relation to any month, all the electricity used by a generating station in that month (whether or not it is generated by the generating station and whether or not it is used while the generating station is generating electricity) for a purpose directly relating to the operation of that generating station, including fuel handling, fuel preparation, maintenance and pumping water.