6.—(1) Subject to article 10, electricity shall be considered to have been generated from eligible renewable sources to the extent that it has been generated from renewable sources and provided that it has not been generated by an excluded generating station as specified in this article and articles 7 and 8.
(2) The following shall be excluded generating stations–
(a)large hydro generating stations except those first commissioned after 1st April 2002;
(b)subject to paragraphs (3) and (4), generating stations (other than micro hydro generating stations) which were first commissioned before 1st January 1990 and where the main components have not been renewed since 31st December 1989 as described in paragraph (5);
(c)generating stations located outside the United Kingdom, except generating stations which are not located on land and which are directly and exclusively connected to a transmission or distribution network located in Northern Ireland; and
(d)generating stations generating electricity under the arrangements or additional arrangements referred to in article 35(1) of the Northern Ireland Electricity Order.
(3) A generating station shall not be an excluded generating station by virtue of paragraph (2)(b) in any month during which it is fuelled partly by fossil fuel and partly by biomass (and by no other fuel).
(4) A generating station shall not be an excluded generating station by virtue of paragraph (2)(b) in any month during which it is fuelled by biomass, if–
(a)prior to 1st April 2003 at least 75 per cent of the energy content of the fuel by which it was fuelled was derived from fossil fuel; and
(b)during no month (being a month after March 2004) after the first month during which it was fuelled wholly by biomass has the energy content of the fuel by which it was fuelled been derived as to more than 75 per cent from fossil fuel.
(5) For the purposes of paragraph (2)(b), the main components of a generating station shall only be regarded as having been renewed since 31st December 1989 where–
(a)in the case of a hydro generating station, the following parts have been installed in the generating station after 31st December 1989 and were not used for the purpose of electricity generation prior to that date–
(i)either all the turbine runners or all the turbine blades or the propeller; and
(ii)either all the inlet guide vanes or all the inlet guide nozzles; or
(b)in the case of any other generating station all the boilers and turbines (driven by any means including wind, water, steam or gas) have been installed in the generating station after 31st December 1989 and were not used for the purpose of electricity generation prior to that date.