By Loz Blain
Solidarityeconomy.net via Gizmag
July, 5 2015 - Temperature readings taken in existing oil and gas bore holes indicate a huge amount of geothermal energy below the surface of Australia. (Credit: Australian Geothermal Energy Association)
Australia is sitting on top of some of the world's most potent geothermal energy sources, according to government estimates. Just one percent of the hot rock energy less than 5 km under the surface would be enough to meet the whole country's entire power needs for 26,000 years if it was tapped. So why aren't we seeing more movement on it?
Geothermal energy is a very handy, virtually inexhaustible clean energy source for those areas lucky enough to find themselves on top of it. Massive amounts of hot rock just below the Earth's surface can be used to heat water and drive steam turbines for reliable electricity generation with virtually no emissions or environmental impact.
Where wind and solar tend to generate power at inconvenient or uncontrollable times, geothermal can be easily regulated and is ready to go 24/7. Surveys testing the available heat in existing bore holes down to a depth of 5 km (3 miles) below the surface indicate that Australia is sitting on some seriously large hot rock resources, as shown in our lead image.
So why is this enormous resource apparently so underdeveloped?
Part of the answer is geographic. Much of Australia's hot rock is simply not conveniently located close to major cities. The big red splotch of prime red geothermal activity to the centre right of the map is more or less on top of a large, barren desert area several hundred kilometres from Sydney or Adelaide, and large scale power transmission can be an expensive proposition.
Another part is geological. Australia has a ton of hot rock, but not a lot of the highly porous rock that makes for easy power extraction. To generate power, you need to be able to pump large amounts of water into a deep rock hole and let the water filter through pores and cracks in the rock, picking up heat as it goes, and then pump the heated water back to the surface on the other side.(more…)