Australian Energy Market Operator (AEMO)
"The National Transmission Network Development Plan (NTNDP) provides an independent, strategic view of the efficient development of the National Electricity Market (NEM) transmission grid over a 20-year planning horizon." >>

https://www.aemo.com.au/Electricity/National-Electricity-Market-NEM/Planning-and-forecasting/National-Transmission-Network-Development-Plan