Aurora Energy carried out a major upgrade to electricity supply for Wanaka. We built a new switching substation to improve the reliability of electricity supplies to homes, farms and businesses.
The project included building a new substation on the corner of Riverbank and Ballantyne Roads, installing a new underground cable to connect to the existing Wanaka substation and upgrading the overhead line along Riverbank Road.
Pictured: New poles being installed for final stage of Wanaka electricity upgrade. Click here to read story.
Project status: Complete
Why was the upgrade needed?
Electricity demand in Wanaka has increased in line with its growing population. We needed to increase the capacity of the network to continue to deliver reliable electricity to all customers and connect supply to new residential housing and businesses. The Wanaka Upgrade is part of Aurora Energy’s major network development programme.
How is electricity supplied to Wanaka?
Electricity is transported from generation sources (such as hydro power stations and wind farms), across the national grid transmission system to the local distribution network, then on to consumers. To supply power to Wanaka and the Upper Clutha, including the Cardrona Valley, Aurora Energy takes high voltage electricity from the Cromwell substation to the Wanaka substation. There it is converted from 66kV to a lower voltage of 33kV to supply the Camp Hill and Cardrona substations and to 11kV to supply Wanaka locally. The power is distributed out around the area to local transformers that convert it further to 230 volts for use in the home, on farm and in businesses.
The new Riverbank Road substation supplies the Wanaka substation at 66kV. The Wanaka substation will continue to supply the Camp Hill substation at 33kV and the Wanaka area at 11kV.
1. Riverbank Road switching station
A new switching substation was built on the corner of Riverbank and Ballantyne Roads, opposite Wanaka Wastebusters. The new substation takes 66,000 volt (or 66kV) electricity from the national grid at Cromwell and control the supply to the Wanaka and Cardrona substations. It provides a hub for the high voltage supply into Wanaka and surrounding areas, and adds capacity to the existing Wanaka substation and be able to reroute supply in the event of a fault. Queenstown Lakes District Council approved the designation for the new substation in 2013.
2. New underground cable Ballantyne Road to Wanaka substation (66 and 11kV)
From the new Riverbank road substation, a new 66kV underground cable has been installed along Ballantyne Road to the Wanaka substation. The underground cable was installed in a trench and then back filled with the existing surface restored.
3. Overhead line upgrade along Riverbank Road (66kV)
We upgraded the overhead power lines along the west side of Riverbank Road between Ballantyne Road and State Highway 6 from 33,000 volts (or 33kV) to 66,000 volts (or 66kV). The existing 16 poles were replaced by 12 taller poles of approximately 17 metres in height. The extra height is needed to provide safe clearance for the higher voltage lines. We also converted the existing overhead service lines that cross over the road to supply houses on the east side of the road to underground cables.
We considered installing the new 66kV supply underground. Due to the type of soil in Riverbank Road, a high voltage underground cable in this location could not be adequately protected against the risk of lightning strike, so an overhead line was the only suitable option.
The route and design of the 66kV overhead line was selected taking into account safety, environmental, maintenance and security of supply requirements. The 1.2 kilometre line will run north along Riverbank Road from the intersection at Ballantyne Road.
The existing power poles at the intersection of Ballantyne and Riverbank Roads, were moved and new poles installed to guide the overhead lines into the new substation. In some locations, the existing overhead lines have had an additional conductor installed above to protect the line against lightning strike. When the Riverbank Road Substation was commissioned, the existing overhead line through the Three Parks development was removed.