Australia’s largest energy transmission project, stretching 900 kilometres across New South Wales, Victoria and South Australia, is being energised following completion of construction.

Australia's biggest transmission project to date - hit by delays and cost overruns - has finally been energised and should be commissioned later this year.

A new high-voltage “superhighway” with a $4.1 billion price tag will soon make it easier to add wind and solar farms to the network.