Two 11,000 volt submarine cables currently supply Scotland Island and 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.
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. This work is ongoing and contributes to long term reliability together with the more comprehensive solutions discussed above. Improvements include:
assessing and upgrading network assets, including existing cables, vulnerable points in the network and isolating capability.
assessing and improving current vegetation management.
improving staff access procedures (including marine transport) and storage of equipment.
improving current work practices and increasing specialist field training for operators
establishing 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:
availability of space around existing utility services
environmental and heritage impacts
cost (minimising the impact on customer electricity bills)
traffic impacts including access to wharves and local roads
stakeholders who may be uniquely impacted by temporary power disruptions or construction
Since the major outage in 2015, there have been six smaller outages on Scotland Island and West Pittwater. These were associated with storm events or vegetation coming into contact with our overhead network and were not been related to the submarine power cables. Access and safety issues have also been challenging during outages in both locations. This has contributed to the time taken to restore 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 are now moving 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 network arrangement and Scotland Island has a circular one.
A number of project scenarios were assessed for each location (including the original cable loop) to arrive at the proposed solutions.
Ausgrid’s proposed solution is to use 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. This will minimise 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.
Work is expected to start in April 2019 and be completed by the end of July 2019. Further project information including construction details, will be sent to residents when finalised.
The linear nature of the network at 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 will be provided to individual households after consultation with market experts. However, based on preliminary consultation the 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 2019.
Home Energy Audits
Ausgrid commissioned local company, Your Energy Friend to undertake home energy audits for interested at West Pittwater. The purpose of the audits was to understand local conditions and household energy use to assist in assessing alternative options. These options included demand management, energy efficiencies, generation and storage options.
Summary finding from the audits were:
Based on the opinion of the auditor and home occupier, approximately 80% of the surveyed properties have some level of solar access or generation potential with less than 10% of properties with solar PV currently installed. This opportunity assumes generation greater than 2-3 hours per day as a minimum, but will need to be qualified with a solar specialist. Areas assessed included the building, but also yard, jetty and infrastructure space.
Almost all households audited indicated a support for or an interest in installing household battery storage systems.
Small appliance ownership was high overall, with an unusually high ownership of heated towel racks and bathroom floor heating, with some systems set to operate 24 hours year-round leading to considerable electricity consumption.
An opportunity exists to reduce power usage with remote controlled power eliminators to switch off small appliances that are using high levels of stand-by power.
Water heater replacement/thermal set point tuning appears to be a prospective opportunity in the
supply area, with such a large number of inefficient electric hot water systems, many of which were observed to have inappropriately high temperature thermal set points.
The dominant driver of electricity consumption appears to be water heating, with a significant number of electric hot water systems in use.
To view the full summary report click on the link below.
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 feedback has been sought since early 2017 to assist the project team better understand household energy usage as well as local resident information. It has also been important to keep the community informed of decision making and analysis so that they understand why we have reached the outcome we have.
Ausgrid has continued to meet with key stakeholders including Northern Beaches Council, Rural Fire Services, National Parks and Wildlife, emergency response teams, local and federal Members of Parliament and community group representatives to collect feedback and provide project updates.
A summary of the 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.