The Department invites tenders for the supply of electricity, together with associated services such as metering (or the capacity to work with 3rd party metering suppliers), data provision, invoicing and site transfers. In the first instance approximately 105 GWh of Electricity is required over 285 sites. In addition to this it is expected that the Department would prefer to roll all the Tranche 5a sites into this contract as soon as practicable. Details of this process will be discussed with the short - listed retailers.