.... Energy consultants realised they were standing not far above an absolutely massive body of water that never deviates from 23°C. In that situation, slashing energy costs is as simple as pumping water from 155m underground through a heat exchanger and sending the warmed water 165m back down below via a second bore about 250m away.
This method of exchanging energy with the Earth’s crust is called low-temperature sedimentary aquifer geothermal, and so far it’s keeping everyone happy at the 80-bed Montgomery House nursing home in Perth.
About 10 years ago there were high hopes for geothermal projects where super-hot water drawn from as far as 5km underground would drive turbines for industrial use, but enthusiasm faded over the years despite extravagant investment. There are plenty of successful applications that use the same basic concept on a less ambitious scale, says Dr Ian Brandes de Roos, a principal hydrogeologist with Perth-based Rockwater Consultant Hydrogeologists. The majority of municipal swimming pools in Perth are heated by geothermal energy, for example, with bores running to about 1km.
“Sedimentary basins are the quiet achievers of the geothermal industry and the low-carbon solutions space,” he says. “We see an energy future with a whole bunch of complementary technologies, and geothermal for heating and cooling of larger facilities is a really important part of the mix.”
