3.—(1) The renewables obligation is that, subject to paragraph (3) and article 7, each designated electricity supplier shall before each specified day produce to the Authority evidence showing–
(a)that it has supplied to customers in Great Britain during the obligation period to which the specified day relates such amount of electricity generated from eligible renewable sources as is determined under article 6; or
(b)that another electricity supplier has done so (or that two or more others have done so); or
(c)that, between them, they have done so.
(2) The evidence referred to in paragraph (1) is certificates issued by the Authority under section 32B of the Act, provided that such certificates relate to electricity generated from eligible renewable sources.
(3) A designated electricity supplier may discharge up to 25 per cent. of its renewables obligation in respect of an obligation period by producing to the Authority certificates which would comply with the requirements of this article except that the electricity to which they relate was supplied in the immediately preceding obligation period.
(4) In respect of any obligation period, no more than 25 per cent. of a designated electricity supplier’s renewables obligation may be satisfied by the production of certificates issued in respect of generating stations which, during the month to which a certificate relates, have been fuelled partly by fossil fuel (as defined in article 8) and partly by biomass (and by no other fuel) and are not minimal fossil use generating stations.
(5) A certificate referred to in paragraph (2) is to be regarded as produced to the Authority as the evidence or part of the evidence required under paragraph (1) in respect of an obligation period where before the specified day the Authority receives from the designated electricity supplier which holds the certificate a notification in writing identifying the certificate to be used and, in the case of a SROC, the SROC identifier (as defined in paragraph 2 of Schedule 2).
(6) Without prejudice to paragraph (5), the Authority may draw up procedural guidelines for the production of certificates as the evidence or part of the evidence required under paragraph (1).
(7) An electricity supplier has a renewables obligation in respect of an obligation period if it supplies electricity to customers in Scotland at any time during that period regardless of whether it supplies electricity to such customers for the whole of that period or not.