The AER is required under Chapter 6A of the National Electricity Rules (NER) to make a transmission determination for TransGrid in relation to the NSW and ACT electricity transmission network. Clause 6A.2.2 of the NER sets out the components of the transmission determination, which include a revenue determination, negotiating framework determination, negotiated transmission service criteria determination and pricing methodology determination for the transmission network service provider.
On 28 April 2009, the AER released its final decision and transmission determination for TransGrid for the regulatory control period commencing 1 July 2009. The determination will establish network charges for the period 2009-2014.
In March 2010, in accordance with orders made by the Australian Competition Tribunal on 25 November 2009, the AER updated calculations of the maxium allowed revenues for TransGrid in the AER's transmission determination (final decision).