Energy purchase contracts
The majority of our electricity contracts and certain of our gas contracts are entered into to meet our expected purchase, sale or usage requirements and so are accounted for as ordinary sales or purchase contracts. These included contractual commitments to purchase energy under long-term contracts amounting to £3,645 million as at 31 March 2009 (2008: £2,061 million) of which £990 million is due within one year (2008: £794 million). Further information is included in note 29 to the consolidated financial statements.