Why geothermal energy is on shaky ground

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Not so long ago, former Australian of the Year, Tim Flannery was proposing that we build a low carbon-emitting city in the outback of Australia called Geothermia. As Flannery wrote:

 

What might it look like? I imagine a solar collector towering over a low-rise city, providing shade and conserving soil moisture. Perhaps the infrastructure would be underground. Geothermia would be a city not of thousands but of hundreds of thousands – a place with its own critical mass. And most importantly it would be a fully sustainable city – Australia’s very first.

Flannery’s imagined utopia, incidentally, was situated quite close to trials being carried out by Geodynamics, a company for which he was an enthusiastic shareholder.

 

The road since then has been a bumpy one for the geothermal industry in Australia, with millions of taxpayer dollars disappearing into the drill-holes and precisely no electricity coming out.

 

This is despite the fact Flannery was telling ABC radio at the time:

 

“There are hot rocks in South Australia that potentially have enough embedded energy in them to run the Australian economy for the best part of a century.

Now, they’re not being fully exploited yet but the technology to extract that energy and turn it into electricity is relatively straightforward.”

What Flannery neglected to tell anyone is that only a few months earlier, one of the first trials of geothermal energy had been abandoned after causing 3,500 earthquakes in Basel, Switzerland. While the shocks only reached 3.4 on the Richter scale, they were enough to cause US$7 million damage to buildings, and land the CEO of the company in court.

 

Geodynamics has since asserted in a statement that an American expert claims:  

 

“The intensity of the seismic events to date that could be blamed on EGS (enhanced geothermal systems) has been well below the threshold of what people normally consider an earthquake.”

 

This is not entirely consistent with reports from the Swiss, like this one:

 “Local police and fire departments received hundreds of phone calls from worried citizens, and some buildings suffered from cracks and broken tiles.”

  

There have since been similar small earthquakes measured in Germany, and the United States close to geothermal projects, and a large one in Mexico that may or may not have been related to the geothermal plant.

 

The problem for the geothermal industry is that earthquakes are not just an unwanted side effect of the process, they are – at least until anyone finds an alternative way of doing it – actually part of the process, and scientists are still a long way from being able to predict or control them.

 

Another problem for the industry is that keeping a large distance between a power plant and consumers of electricity will greatly increase the cost of power. In fact, if geothermal power plants cause earthquakes, it won’t even be a safe option for powering mining operations in remote areas, let alone a glittering sustainable metropolis like Geothermia.

 

There is much more on the subject here and here.  



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