Overview
A reliable and affordable electricity supply is essential to supporting Sydney’s economy.
Parts of the current electricity transmission network were built in the 1960s and 1970s and some underground cables are now approaching the end of their serviceable life.
As Sydney’s population grows, the demand for electricity is increasing and replacement of the ageing infrastructure will secure the future supply for residents and businesses in Sydney’s CBD and surrounding suburbs.
Powering Sydney's Future involves:
- installing a new 20km 330kV underground cable between Potts Hill and Alexandria
- upgrading substations at Potts Hill, Alexandria and Picnic Point
- installing additional pipes so there is space for a second cable to be added in the future as demand increases, avoiding future disruption to local communities
- constructing special crossings, such as cable bridges or underbores (underground crossings), for the cable circuit to cross rail corridors, rivers or parks
- temporary use of some public spaces as ‘laydown areas’ during the construction of the project, for the storage and assembly of equipment.
Works commenced in August 2020, with main construction completed in July 2022 and road restoration works completed in June 2023.
Overview of works
Powering Sydney's Future will secure a reliable electricity supply through economically viable solutions, with minimal community and environmental impacts.
A new 20-kilometre 330kV underground cable has been installed, mostly along roads, with some work in parks. We have constructed cable bridges and drilled under the ground at some locations to cross rail corridors, rivers, main roads and major underground utility services.
The project includes upgrades to our substations at Potts Hill, Alexandria and Picnic Point.
During construction we have also installed conduits for extra cables, to miminise disruption to local communities when extra network capacity is required in the future.
We engaged global cable solutions provider, Taihan, to design and construct the new cable.
Selecting the preferred route
We proposed a preferred cable route in 2017 after examining more than 30 route options. As part of our planning and consultation for the project, a new cable route was identified which would lower the construction impacts for local communities.
The revised cable route primarily follows local roads and some main roads.
About construction
Along most of the route, we dug a trench about three meters wide by 1.2 meters deep and installed conduits (pipes) before refilling the trench and temporarily restoring the road surface or other areas such as parks. To cross waterways and rail lines, we built special cable bridges or drilled below ground to install the conduits (pipes).
At approximately every 900 metres along the route our construction crews have installed precast underground ‘joint bays’. We use the joint bays to pull the sections of cable into the conduits and then join the cable sections together.
