Metro Tunnel Project trial reveals how geothermal energy can reduce emissions

Metro Tunnel Trial

carbon emissions, metro tunnel project, Rail Projects Victoria, renewable energy, renewables, sustainability, technology,


Metro Tunnel’s new State Library Station in Melbourne trials a world-first method to capture geothermal energy, potentially starting a revolution in clean energy.

The trial, a finalist in the Premier’s Sustainability Awards, found that building foundations can be used as a thermal ‘battery’ to capture renewable energy. The potential emissions savings are equivalent to taking hundreds of cars off the road yearly.

It involved a team of researchers burying plastic pipes inside concrete foundation piles that were then installed 40m underground as part of a retaining wall during the early months of construction on the new station.

With the ground remaining at a stable temperature throughout the year, water pumped through the pipes absorbs heat from the ground in winter and releases heat into the ground in summer.

When the water comes back to the surface, the temperature change can be used to heat or cool the building efficiently.

Diagram of Geothermal heat exchange

Over the past four years, researchers have used sensors to test different scenarios, varying the flow of water through the pipes and the number of pipes used at a time to find the most energy-efficient method while also checking the temperature change did not affect the retaining wall.

The trial found a train station such as State Library Station could use the system for all its heating and cooling needs – and even help warm and cool the buildings surrounding it.

A team led the research from the University of Melbourne’s Faculty of Engineering and Information Technology, in partnership with Metro Tunnel Project delivery agency Rail Projects Victoria and its construction contractors CYP Design & Construction.

It’s part of a massive effort by the Metro Tunnel team to embed sustainability across the project, including diverting between 72 and 90% of construction waste from landfill, installing 170kW of solar panels on the Arden Station entrance building and the Sunshine Signal Control Centre, and even a trial to wash and re-use safety gloves.

Source: © State Government of Victoria, Australia 2022

Image Source: © State Government of Victoria, Australia 2022

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