Underground Substation in Australia is a Win-Win

Haymarket Gas Insulated Switchgear (GIS) Substation Design and Construction

Creating the largest underground substation in Australia and devising an ingenious "labyrinth" to capture escaped gas.

The Challenge
Transgrid NSW required a substation to meet the growing demand for power in Sydney and to address the ageing infrastructure. The challenge was to maximise the real estate available to construct the substation, given space is at a premium in the central business district of Sydney. Another crucial element of the Haymarket project was the gas capture and recovery system, which is an important consideration given the close proximity of buildings in the CBD in relation to the substation. The positioning of energy infrastructure of this magnitude in the CBD was a major requirement of the customer.

The Solution
Siemens built the Haymarket substation in a five-storey building, three of which are underground and contain 28 bays of gas insulated switchgear plus Australia's first gas insulated transformers. The systems installed included 23 bays of the Siemens 132kV 8DN8 gas insulated switchgear, and four bays of the 330kV 8DQ1 gas insulated switchgear. Siemens created a labyrinth to capture and recover any escaped gas: this system is a world first innovation in the management of gas. The Haymarket substation is now the largest underground substation in Australia.

The Outcome

• Ensured certainty of power supply for the Sydney CBD and southern suburbs
• Achieved economies of space: the multi-storey building directly above the substation is an added benefit, given space is at a premium in the central business district
• Installed auxiliary power, lighting, air conditioning, security, fire protection and a building management system to the building, designed to carry a future nine-storey office tower
• Used SF6 – a non-flammable greenhouse gas – in the transformers, so the capture and recovery has important environmental and safety implications
• Devised an innovative solution to the problem of escaped gas

Solution Overview and Case Study

via Siemens