The Electricity and Gas (Energy Efficiency Obligations) Order 2001
Article 2(1) of this Order imposes on each electricity and gas supplier which, on 31st December 2001, supplies in any part of Great Britain at least 15,000 domestic consumers, an obligation to achieve improvements in energy efficiency over the period beginning on 1st April 2002 and ending immediately before 1st April 2005. Article 2(4) makes corresponding provision for those suppliers whose domestic consumers in Great Britain are fewer than 15,000 on 31st December 2001 but are at least 15,000 on 31st December 2002. Article 2(5) makes corresponding provision for those suppliers whose domestic consumers in Great Britain are fewer than 15,000 both on 31st December 2001 and on 31st December 2002, but are at least 15,000 on 31st December 2003.