Aurora Energy has built a new, higher capacity substation at Camp Hill Road, Hawea to cater for increased electricity demand in the surrounding area and ensure reliable electricity supplies to homes, farms and businesses.
Project status: completed November 2015
The substation site is located 500 metres west of the Hawea River on Camp Hill Road, Hawea. The site is about 12 kilometres northeast of Wanaka and 8 kilometres south of Lake Hawea.
What is a substation?
A substation is a part of the electricity supply system that carries electricity from generation sources (such as wind farms and hydro power stations) across the national grid transmission system to the local distribution system then onto consumers. A distribution substation takes high voltage electricity and converts it to a lower voltage. Camp Hill substation is designed to take electricity at 33,000 volts (or 33kV) and convert it to 11,000 volts (11kV) for distribution via feeders to local transformers that convert it further to 230 volts for use in the home.
Why is a new substation needed?
Electricity demand in the Hawea, Hawea Flat and Maungawera area has increased as irrigation use and the local population has grown. Historically, electricity demand in the area has peaked in winter with home heating. With increased irrigation use, the highest peak is now in summer. The existing Maungawera substation that supplies the area has reached its capacity for reliable supply. The new substation at Camp Hill increases the maximum capacity from 3 MVA (megavolt amperes) to 7.5 MVA to accommodate increased electricity demand and peak usage in summer and winter.
Camp Hill was chosen as the preferred site because it is well-positioned in relation to where the electricity is being used and the wider electricity distribution network. This location allowed us to build four high voltage (11kV or 11,000 volt) distribution feeders to improve the reliability of local electricity supply (if there is an outage on one feeder, consumers on the other three feeders will be unaffected). The site is also on the potential path for a future 66,000 volt (66 kV) sub-transmission line ring that when built will provide an even higher level of electricity supply security in the Upper Clutha area. Importantly, the site is flood-free, flat and easily accessed from the road.
The entire site is about 1.44 hectares. Built structures occupy about 4,000 square metres or around a third of the site and include a power transformer, circuit breaker, electrical switchgear and power poles. There is one building, the switch room, approximately 10 by 6.3 metres and 5.5 metres tall – about the size of a large double garage. The exterior has been finished in natural colours (browns, greens or greys) with screen planting.
The tallest structures are five power poles installed inside the substation fence, lower in height to the ones already along Camp Hill Road (about 8 metres). The other electrical equipment on site is free-standing and approximately 4 metres in height. For safety reasons, we are required to place high voltage electricity equipment at specified heights to meet the industry safety regulations.
We have taken care in the site design to minimise the visual impact. The substation is set back from the road and there will be extensive screen planting around the perimeter fence. A detailed landscaping design was developed to minimise visual impact, approved by Queenstown Lakes District Council.
Construction started in April 2015 and the project completed in November 2015. The construction phased include cabling and overhead line construction, civil works on site (earthworks to level and shape the site, laying concrete pads and foundations), then installation of the electrical equipment, landscaping and planting, testing and commissioning.