From the sewer to a sustainable heating solution

The way commercial and community facilities are heated would be transformed under an innovative project being led by the Barwon Water Group.

The corporation has been fully powering its operations with renewable electricity since mid-2024, via investments in solar and wind energy.

It is now progressing a bold plan to capitalise on an under-utilised energy resource that is flowing freely underground.

About 1000 million litres of warm wastewater is generated by Victorian residents and enters the sewerage system every day.

Barwon Water and Barwon Asset Solutions have been investigating how to tap into this resource, via Wastewater Heat Recovery (WWHR) technology.

“We’re excited by the potential to harness the heat in this wastewater and use it to create a sustainable power source,” Barwon Asset Solutions General Manager Anna Murray said.

“Turning a hidden energy source into a clean, circular heat solution is a huge step toward decarbonising community infrastructure.

“There are significant benefits to be gained, from operational cost savings, an easing of demand on the power grid and a reduction in carbon emissions.

How will it work?

The project aims to capture the thermal energy from the wastewater using a heat exchanger and then transfer it to a water-sourced heat pump.

The energy-efficient heat pump then takes the water, which is typically around 20°C, and raises it to a temperature high enough to heat the facility.

When paired with renewable electricity such as solar or wind, WWHR systems can effectively operate as a zero-emissions solution.

WWHR systems have been implemented in many countries across the world, with Victoria having the right conditions for it to succeed here.

What could it achieve?

By implementing WWHR, one swimming pool alone could save nearly $300,000 in heating costs per year.

It could also cut gas use by 20,000 Gigajoules (GJ) and prevent more 1000 tonnes of carbon dioxide (CO₂) equivalent emissions.

This reduction is roughly equal to removing 350 petrol cars from the road for a year, or avoiding the energy needed to power 200 Australian homes annually.

What comes next?

The project has gained momentum this year, with a pilot installation due for commissioning at Barwon Asset Solutions depot in Breakwater in early 2026.

An opportunity is also being pursued, in collaboration with the City of Greater Geelong, to implement the technology at the Leisurelink Aquatic and Recreation Centre.

The project has also captured wider attention in the water sector, after jointly winning the 2025 Water Minister’s Climate Innovation Challenge.

The Challenge calls on Victorian water corporations to develop bold, practical ideas that can inspire climate action across the water sector and beyond.

The $75,000 prize money from the award will support the assessment of likely WWHR locations across Geelong.

Through an Australian-first wastewater heatmapping study, the corporation will learn more about the heating and cooling capacity of the city.

This will show what can be achieved for possible sites such as industrial precincts, hospitals, recreation centres, and water reclamation plants.

Note: Barwon Asset Solutions is a wholly owned subsidiary of Barwon Water, specialising in quality asset maintenance, land management and project services across a variety of industry sectors.