About substations

What is a substation?

Substations form an important part of the electricity network, providing power to you every time a light switch or appliance is turned on.

Substations 'step' or 'convert' power voltage up or down so that electricity can be delivered from power generators (very high voltages) through to your home, workplace and community (very low voltages).

In a state that is continuing to develop and grow there is an increasing demand to provide electricity across the power network. As homes continue to use more and more power, and industry, communities and businesses continue to grow, more substations will be required.

More information:

Types of substations

Terminal substationThere are three main types of substations across the our network:

Each substation has a unique function and plays an important role in providing power throughout the SWIS.

Terminal substation

Terminal substations are the largest of the substations and are best located close to or within an area with high electricity requirements. They are generally located outside of densely populated areas to accommodate the amount of land required, which is usually within the vicinity of 330 metres x 680 metres.

Terminal substations service vast areas and form an interface between the high voltage network and the low voltage network.

Zone substationFor 330,000 volt terminal substations there can be up to eight incoming/outgoing transmission lines to connect the network together.

For 132,000 volt terminal substations there are generally 12 incoming/outgoing transmission lines to connect the network together.

Zone substation

Zone substation receive electricity from terminal or other zone substations and covert it to the lower voltages required for homes and businesses.

It is important that zone substations are located close to the people and communities they service.

Zone substations generally require a piece of land around 110 metres x 110 metres in size. Once developed, zone substations are generally connected to the network using between two and four lines.

Screened zone substation

Distribution substation

Distribution substations are the smallest substations. They reduce the voltage down to a level usable by homes and businesses and supply a much smaller area than a zone substation - for example; a few streets or even a single customer. They are around 5 meters x 5 meters in size.

Identifying substation sites

Once we has identified a number of potential sites within a study area, each solution is assessed against the social, environmental, technical and economic considerations. Through this process, a preferred option is identified and put forward for the relevant internal and external approvals.

Where possible, we seek input into this process from our stakeholders, including the community.