Hot Rocks

The question of greenhouse emissions and global warming highlight the pressing need to develop alternative pollutant free sources of energy. Sun, wind and water play only a minor role as an alternative energy sources, satisfying 18% of the world energy needs.

Recent studies indicate the possibility of an abundant renewable energy supply just below our feet, in the form of hot rocks. We are all familiar with molten rock breaking through the earths crust to spew lavy into the atmosphere but in such a state it is far too hot and difficult to harness as a viable energy source.However just below the earths surface there are vast pockets of hot granite rocks with enough heat to drive steam turbines and generate electricity.

Dr Doone Wybong from the Australian National University and his geophysicist colleague, Dr Prame Chopra, have spent two decades searching for clues to the whereabouts of this energy source, which is as old as the earth itself. If they are able to locate reasonable reserves of theses rocks, our energy problems would largely be resolved.

How does the idea work? The technology is ingenious !!

Water is injected into a borehole and circulated through a "heat exchanger" to hot cracked rocks several kilometres below the surface. The water is heated through contact with the rocks and is then returned to the surface through another borehole where it is used to generate electricity. The water is then re-injected into the first borehole to be reheated and used again.

The heat used in this hot rock energy process is eventually replaced by the Earth; it can be classified as renewable energy.

Heat mining for the future?

For further technical data and the complete interview click here.