Why do we need Powering Sydney's Future?
The inner Sydney network supplies electricity to more than 500,000 customers in Australia's biggest city. Parts of the network are over 50 years old and are approaching the end of their serviceable life. Powering Sydney's Future is TransGrid's response to this ageing network and increasing electricity demand in a growing Sydney. A reliable electricity network is essential to support growth, and we are working towards a solution to ensure inner Sydney's needs are met now and into the future. The Potts Hill to Alexandria transmission cable project is a crucial part of this solution.
What is the Potts Hill to Alexandria transmission cable project?
We are proposing to construct a new 330 kV underground cable circuit between our substations at Potts Hill and Alexandria. To avoid future disruption we are proposing to install additional infrastructure to allow for a second cable circuit at a later stage.
The preferred route for this project primarily follows local and main roads and is around 20km long (see route overview inside). The new cable circuit would mainly be installed underground with some cable bridges to cross rail lines and waterways. You can view a more detailed map online at https://transgrid.mysocialpinpoint.com.au/psf#/
How will Powering Sydney's Future project be built?
For most of the alignment we would dig a trench about 3 metres wide by 1.2 metres deep, install conduits before burying them and temporarily restoring the area. To cross waterways and rail lines, we are proposing to build special cable bridges. We anticipate that each cable drum section will take up to eight weeks to install (most properties would be exposed to around two weeks of trenching activity).
Joint bay construction:
Joint bays are built by digging an underground bay, allowing the cables to be installed in sections. Joint bays are usually installed every 600 to 800 metres along the trench. Once the joint bays have been built, they would be accessed later to install the cables (cable pulling and cable jointing).
Once the joint bays are connected by conduit, sections of the transmission cable can be installed. This typically takes about two weeks, weather permitting.
Once the cables have been installed in the conduits, they are joined together inside the joint bays. This would typically be done soon after the cable pulling towards the end of construction. Cable jointing is completed inside a covered enclosure.
Change to the preferred route at Sydney Park
The preferred transmission cable route for the Potts Hill to Alexandria transmission cable project was announced in June 2017, with an indicative alignment for a section of the cable travelling through Sydney Park. After further investigations, TransGrid has modified the location of the preferred cable route to minimise potential impacts to the Sydney Park wetlands.
The proposed alternative route would enter Sydney Park from Barwon Park Road near the City of Sydney Park Nursery Depot and follow the edge of the Park towards Euston Road. TransGrid is continuing to work with City of Sydney to minimise impacts to the park and will confirm the final location of the route as the project progresses. Please refer to the interactive map for further details of the proposed alternative route: https://transgrid.mysocialpinpoint.com.au/psf#/
What are the next steps?
We are finalising the Environmental Impact Statement (EIS), which will be placed on public display in mid-2019. TransGrid will be in touch with stakeholders as well as community members living or working along the preferred cable route to let them know how they can provide feedback during the EIS exhibition.
We need your input
We welcome your input so we can best understand how this project might affect the communities along the cable route. You can visit our online feedback portal to share your thoughts about the project. While the EIS is being finalised, your comments will still be considered, and they will be addressed in a submissions report that will be released after the EIS exhibition.
How will Powering Sydney's Future benefit you? Click below to find out