Scotland Island reliability project

 Scotland Island

Ausgrid is planning to improve the reliability of the local power supply to Scotland Island and West Pittwater (McCarrs Creek, Elvina Bay, Lovett Bay and Southern Morning Bay) following extended power outages.

Project need

Two 11,000 volt submarine cables currently supply Scotland Island and the West Pittwater.  Ausgrid has been considering a broad range of options aimed at improving energy security to the area following extended power outages in December 2013 and February 2015.

Project planning

Ausgrid has already implemented a range of measures to improve the reliability of the power supply, and are continuing to investigate longer term solutions.  

Short term improvements

You may have noticed Ausgrid staff undertaking work in your area in recent months. This work is ongoing and contributes to long term reliability together with the more comprehensive solutions discussed above. Improvements include:

  • Assessment and upgrades of network assets including existing cables, vulnerable points in the network and isolating capability.
  • Assessment and improvements to current vegetation management.
  • Improvements to staff access procedures (including marine transport) and storage of equipment.
  • Improvements to current work practices and increased specialist field training for operators.
  • Establishment and roll-out of an improved community information system.

As Ausgrid continues to develop this project, there are a number of factors being considered consider, including:

  • community impacts
  • availability of space around existing utility services
  • environmental and heritage impacts
  • cost (minimising the impact on customer electricity bills)
  • technical feasibility
  • traffic impacts including access to wharves and local roads
  • stakeholders who may be uniquely impacted by temporary power disruptions or construction.

Project investigations

Since the major outage in 2015, there have been six smaller outages on Scotland Island and West Pittwater. These have been associated with storm events or vegetation coming into contact with overhead networks and have not been related to the submarine power cables.  Access and safety issues to both locations have been a challenge in the event of outages, and contribute to the time taken to restore electrical power.

Ausgrid has been progressing feasibility and design studies and working with industry experts to determine the best solution for each community. As a project team, we have assessed a number of options and now have a clear way forward. These solutions aim to minimise the impact of electrical outages to the residents and businesses of Scotland Island and West Pittwater.

The investigations concluded that two different approaches are required for Scotland Island and West Pittwater due to the layout and design of the existing electricity network in each of these areas. West Pittwater has a linear and Scotland Island has a circular network arrangement. A number of project scenarios were assessed for each location including the original cable loop to arrive at the proposed solutions.

Scotland Island

Ausgrid’s proposed solution is to utilise Horizontal Directional Drilling (HDD) to create a bore from Church Point to Carol’s Wharf, Scotland Island which will house a new electricity cable. Both the new and existing cable will be in service at the same time in order to minimise the impact of a failure to a single cable. The new cable will lie in a conduit (pipe) below the ocean bed rather than on the ocean floor as the current cable does, which minimises the risk of impact or damage.

As part of the design for the HDD bore, Ausgrid is considering future energy requirements for the Island and the possibility of including NBN cables or fibres.

Ausgrid intends to have a detailed design completed by mid- 2018. Further project information including construction details, will be sent to residents in early 2018.

West Pittwater

The linear nature of the network on West Pittwater means there is no traditional ‘poles and wires’ solution that can address all the types of outages faced in the area. As such, Ausgrid is proposing to install a hybrid solution to address the various types of network outages being experienced. 

Details of the final solution are still to be determined and relies on more detailed information from individual households and consultation with market experts. However, based on preliminary consultation this hybrid solution will most likely be a combination of technologies such as household batteries and solar, plus a hybrid community generator. Ausgrid will be seeking expert market input in early 2018.

Project approval process and environmental assessment

Under the Environmental Planning and Assessment Act 1979, Ausgrid is the determining authority for this project. An environmental assessment will be prepared on the  works in accordance with Part 5 of the Environmental Planning and Assessment Act 1979 and Clause 228 of the Environmental Planning and Assessment Regulation 2000.

Community engagement

Community feedback was sought in March 2017 to assist the project team better understand household energy usage as well as local resident information.

Ausgrid has continued to meet with key stakeholders including Northern Beaches Council, emergency response teams, local and federal Members of Parliament and community group representatives to collect feedback and provide a project update. 

Project team representatives also held a second series of drop in sessions in December at The Waterfront Café at Church Point to answer questions about the home energy audits, project planning so far, and to talk to local community members.

Community feedback (including initial survey responses) has assisted Ausgrid to confirm the proposed solutions for Scotland Island and West Pittwater. A summary of initial community feedback received and how it has been considered can be viewed via the link at the top right of this page. 

To find out more or provide feedback to Ausgrid, please get in touch via the contacts on the right of this page.

Next steps

Ausgrid will continue to update and engage both communities and stakeholders as we implement immediate improvements and continue to develop the proposed long-term reliability solutions.

December 2017

Further investigations into West Pittwater solution and development of energy market brief

Now – mid 2018

Design and approval of the new underground cable for Scotland Island

Now and 2018

Implementation of short term measures in both areas

January 2018

Home Energy Audits West Pittwater

Mid 2018

Construction to commence for Scotland Island cable

End 2018

Developed design for West Pittwater solution