Geothermal heats up

Geothermal experts from the University of Melbourne are working with the Department of Primary Industries to demonstrate the efficiency of a form of renewable energy that will play an important role in Victoria’s future energy mix.

The State Government recently announced a $1.6 million grant to support the work of the University of Melbourne and its industrial partners, Geotechnical Engineering and Direct Energy.

Professor Ian Johnston and team members from the University’s Department of Infrastructure Engineering Geotechnical Research Group and its partners welcomed the grant and the opportunities the funding will provide.

“This is a significant shift in the way we think about heating and cooling our buildings,” Professor Johnston said.

“Our trial will collect important data about the use of direct geothermal energy systems in Victorian conditions, to help develop greater efficiency in installation practices and design.

“Although direct geothermal energy is still a relatively new concept in Australia, this technology is used extensively overseas with an estimated three million installations worldwide.

“The capital costs of installing a direct geothermal system are still a little high. But with industry becoming better geared to needs, and with better systems of design and installation, prices should fall significantly over the next year or two. This, combined with the likely major increase in the cost of conventionally derived energy, will mean that capital costs can be recovered in a few short years.”

Under the project, the University of Melbourne Geotechnical Group, Geotechnical Engineering and Direct Energy will install geothermal heating and cooling systems into a range of buildings around Victoria and will monitor their performance.

Geothermal energy has the potential to reduce greenhouse emissions and cost of heating and cooling by up to 75 per cent. Direct geothermal energy uses the ground up to several tens of metres below the surface to extract heat in winter for heating and to reject heat in summer for cooling.

Geothermal energy systems work by circulating fluid, water or refrigerant, down pipes that are installed within building foundations or into purpose-drilled boreholes or trenches, and back to the surface again. In winter, heat contained in the circulating fluid is extracted by a ground source heat pump, and used to heat the building. In summer, the system is reversed, with heat extracted out of the building by the heat pump, transferred to the circulating fluid, and then deposited underground.

While geothermal energy does not generate or replace the need for electricity, it is an electricity-saving technology, with the potential to greatly reduce our carbon footprint.

www.ie.unimelb.edu.au