Determination of ineligible quantity
54.—(1) Where this Chapter applies in respect of a supply contract, that part of—
(a)the quantity of gas supplied in any period which was used to generate grid-delivered electricity, or
(b)the quantity of electricity supplied in any period which, having been stored, was grid-delivered, together with a corresponding proportion of the electricity used or lost in storage,
is an “ineligible quantity” for the purposes of the scheme.
(2) In paragraph (1)(b) the corresponding proportion is the proportion of all of the electricity stored and not used or lost in storage that corresponds to the amount of grid-delivered electricity.
(3) Where this Chapter applies in respect of a supply contract—
(a)the supplier must as soon as practicable after receiving the customer’s declaration under regulation 53(1)(b) give notice to the customer of each periodic declaration date and the declaration period for each such date;
(b)the customer must, as soon as practicable and in any event within the period of 14 days beginning with each periodic declaration date, determine and send to the supplier a declaration of the quantity of electricity supplied in the relevant declaration period which is an ineligible quantity;
(c)the supplier must, on the basis of the ineligible quantity declared in each such declaration—
(i)determine the amount of the supply quantity for the declaration period to which the discounted supply price is to apply;
(ii)determine or redetermine its charges for energy supplied in the declaration period accordingly.
(4) The contract parties may agree a basis on which—
(a)an estimate of the ineligible quantity will be used in determining charges for a billing period before the steps in paragraph (3) are completed, and
(b)a subsequent reconciliation will be performed when those steps are completed.