71.—(1) This regulation applies to an accredited RHI installation—
(a)where the heat is generated from solid biomass contained in waste (“Case A”); or
(b)where the heat is generated from solid biomass, not being solid biomass contained in waste, and the capacity of the installation is 1MWth or above (“Case B”).
(2) In Case A, the periodic support payment calculated in accordance with regulation 64 to 66 shall be reduced pro rata to reflect the proportion of the energy content of the waste used in the relevant quarterly period which was composed of fossil fuel and, where fossil fuel has been used for permitted ancillary purposes in accordance with regulation 37, to reflect the proportion of fossil fuel so used which resulted in the generation of heat.
(3) In Case B, the periodic support payment calculated in accordance with regulation 64 to 66 shall be reduced pro rata to reflect the proportion of fossil fuel contamination in the relevant quarterly period determined in accordance with regulation 38 and, where fossil fuel has been used for permitted ancillary purposes during the relevant quarterly period in accordance with regulation 38, to reflect the proportion of fossil fuel so used which resulted in the generation of heat.