The Honourable Michael O’Brien, Victorian Minister for Energy and Resources, has announced a 1.6 million dollar Department of Primary Industries grant to fund researchers from the Department of Infrastructure Engineering, headed by Golder Associates Chair of Geotechnical Engineering Professor Ian Johnston, to work on a series of geothermal energy projects around Victoria with partners Geotech Pty Ltd and Direct Energy Pty Ltd.
Mr O’Brien said that geothermal energy has the potential to immediately reduce greenhouse gas emissions.
“As a clean, renewable source of energy, direct geothermal has the potential to play an important role in the energy mix of Victoria’s future”‘ he said.
Although still a small industry in Australia, geothermal technology is used extensively overseas, with an estimated 3 million installations worldwide.
This project is designed to collect important data about the use of direct geothermal energy systems in Victorian conditions, in order to help develop greater efficiency in installation practices and design. In-ground data will be collected from instruments placed in direct geothermal systems that will be installed in many new and retrofit buildings constructed around the state. The project will also engage and educate the general community about direct geothermal energy, as well as provide specific training to the trades and professions so that the technology can be rolled out in Victoria.
Geothermal energy has the potential to reduce greenhouse emissions and cost of heating and cooling by up to 75%. Direct geothermal energy uses the ground, down to several tens of metres below the surface, to extract heat in winter for heating and to sink 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 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.
“For each kilowatt of electrical energy put into a direct geothermal system, about 4 kilowatts of energy is developed for the purposes of heating and cooling, reducing the energy cost by 75%,” Professor Johnston says.
Therefore, outside the capital costs of installation, 75% of the power generated is free. In addition, as much of the electrical energy in Victoria is generated by brown coal, replacing 75% of energy with a clean renewable source, reduces the greenhouse gas emissions by 75%.
Globally, installation of direct geothermal systems has largely been driven by the heating, ventilation and air conditioning industry. There has been little input from geotechnical engineers or measurement to optimise system design and performance. This has led to many ‘approximate’ sets of guidelines, resulting in systems that are not as efficient, or cost-effective and competitive as they could be.
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.
“With better technical information, the systems developed will be more cost-effective and competitive,” says Professor Johnston.
“We will show that direct geothermal energy is a reliable, cost-effective and renewable form of energy for a wide range of domestic, commercial and industrial applications where heating and cooling is required”, Professor Johnston says.
This project is being funded by the Victorian Department of Primary Industries through the Energy Technology Innovation Strategy: Sustainable Energy Pilot Demonstration (SEPD) Program . For further information please contact Professor Ian Johnston at the University of Melbourne.