ENERGY SECURITYExperts Discuss Geothermal Potential
Geothermal energy harnesses the heat from within Earth—the term comes from the Greek words geo (earth) and therme (heat). It is an energy source that has the potential to power all our energy needs for billions of years.
Taking a soak in a thermal spa might seem a much-needed break, worlds away from the relentless election campaigning, but they’re actually more related than you might think.
One of the biggest election issues we’re seeing in this campaign is what type of energy Australia should be using to power our homes and businesses into the future.
The warm water in a thermal spa is a surprising clue to an energy source that has the potential to power all our energy needs for billions of years.
Geothermal energy harnesses the heat from within Earth—the term comes from the Greek words geo (earth) and therme (heat).
At around 6,400 kilometers beneath our feet, the center of Earth is as hot as the surface of the sun at more than 5,000°C. As underground water moves up from the center of Earth towards the surface, it gets progressively cooler.
But just hundreds of meters below ground, Earth is often still warm enough for natural groundwater to heat swimming pools (both natural and built), warm houses and be put to industrial uses. This heat is continually replenished by the decay of naturally occurring radioactive elements deep within Earth.
It’s something sometimes described as “natural nuclear” energy.
While the dangerous radioactive decay materials remain deeply and safely buried, the benign heat conducts upwards to the surface.
Because of this slow decay, geothermal energy sources remain available for potentially billions of years, ensuring an essentially inexhaustible energy supply that doesn’t require battery storage.
But geothermal technologies are not well known in Australia—until now, we hope.
Two Ways to Use Geothermal Energy
The easiest way to harvest geothermal energy is as “direct heat” from the warm groundwater.
This is captured by simply pumping the warm water to where it is needed if the temperature is right for the purpose or through Ground Source Heat Pumps (GSHP).
The GSHP systems boost the energy to a high temperature and are already used to heat buildings around Australia, including the Geoscience Australia and War Memorial buildings in Canberra and Antarctic Tasmania in Hobart.
Countries like Iceland, New Zealand and many others with natural volcanic resources already use their access to hot water and naturally occurring steam to generate electricity using steam turbines.
