some useful press coverage for geothermal

A good article on geothermal by Graham Cooke in today's Sunday Canberra Times p22.



I meet a lot of people who want to talk about Australia's clean, green energy future. For the most part they are spinning like tops, assuring me the drawbacks to solar, wind and wave generation will be overcome given time and healthy research and development grants.

Now I might be dumb but I cannot see how time and money is ever going to make the sun shine at night, the wind blow continuously or keep the surf up permanently. Biomass seemed to be promising, but agricultural economists are warning of potentially devastating competition between acreage required to grow fuel and that needed to feed an ever-increasing and hungry global population.

As for the nuclear option, despite being the Saudi Arabia of uranium resources, Australia is committed not to use any of it here. I don't agree with that position, but we have a government elected on a no-nuclear promise, and the people have spoken and so on.

Clean coal reminds me of the old army stories about squaddies having to whitewash the contents of the coal scuttle in the officers' mess. Does anyone believe in it outside the coal industry? As for carbon geosequestration, can there be guarantees that once vast quantities of greenhouse gases are pumped underground they will stay there for ever and not leak back up to blight future generations - or is that something we don't worry about because it's not going to be our problem?

One possibility that deserves far more attention than it is getting is geothermal power. In most alternative energy discussions it seems to warrant little more than a footnote and yet its possibilities as a reliable and long-lasting resource are undeniable.

Geothermal energy involves tapping into the heat generated by the earth's core and the gradual decomposition of natural radiation occurring in rocks, principally granite. At depths of around 5km, this can be more than 250C, turning water into super-heated steam that is pumped to the surface to power electricity turbines, then returned to the ground to heat up again and repeat the process.

We have known about the possibilities of geothermal energy for more than a century, but for most of that time it was believed it could only be utilized in actively volcanic areas such as New Zealand or Iceland. As Australia has little or no volcanism we were deemed a non-starter.

However, research in the past 30 years has revealed the potential of hot rock buried deep underground, and guess what? Australia has lots of hot rock.

There are more than 30 companies interested in the project and one, Geodynamics, is on the verge of delivering geothermal electricity from its Cooper Basin site in South Australia. Small beginnings, but managing director Gerry Grove-White is convinced geothermal will play a major part in Australia's energy future.

"Increased green power production and linkages with the national electricity market will improve security of supply in an era of uncertainty, with zero emission power certain to be competitively priced following the introduction of an emissions trading scheme," he says.

The Cooper Basin is remote, and the cost of bringing electricity to the cities high, but the possibility of hot rock sources much closer to population centres exists. As Geoscience Australia's project geologist Fiona Holgate points out: "We simply don't know. We are new to this game and one of our purposes is to improve the database."

Money to support and accelerate this project will be money well spent - at least better than trying to get the sun to shine at night.