29. Where a plant is generating heat from biogas, the following additional metering requirements apply—
(a)a class 2 heat meter must be installed to meter any heat directed from the plant combusting the biogas to the biogas production plant; and
(b)a class 2 heat meter must be installed to meter any heat supplied to the biogas production plant from any source other than—
(i)the plant combusting the biogas; and
(ii)where the biogas has been produced by anaerobic digestion, the feedstock from which it was produced.