Hot Dry Rocks, Oh Yeah!

Keywords: [resources], [energy], [geothermal energy], [alternate energy], [renewable energy], [green energy].

Not much has changed since the age of steam. If you live in Australia or North America, the computer screen on which you are reading this text is most likely to be powered by coal. Think about it. State of the art technology, powered by coal!

Electricity demand continues to expand worldwide, with consumption projected to grow by nearly 100% by 2020 (International Energy Outlook 2001). Electricity generation generally relies on burning fossil fuel which produces carbon dioxide (CO2) as one of its waste products. Concern has developed over the last decade about the effects of carbon dioxide (a greenhouse gas) on the atmosphere, particularly with respect to global warming.

Fossil Fuel Alternatives: The expansion of the nuclear power industry appears to be socially unacceptable. Solar and wind power cannot replace fossil fuels, just augment them and they are limited in scope, intermittent, and unreliable. Large-scale hydroelectric projects are now rejected on environmental grounds.

Hot dry rocks (HDR) has the potential, worldwide, to significantly reduce our dependence on fossil fuels.

HDR geothermal energy relies on existing technologies and engineering processes, and is the only known source of renewable energy with a capacity to carry large base loads.

The concept behind HDR geothermal energy is relatively simple. Heat is generated by special high heat producing granites located 3km or more below the Earth's surface. The heat inside these granites is trapped by overlying rocks which act as an insulating blanket. The heat is extracted from these granites by circulating water through them in an engineered, artificial reservoir or underground heat exchanger.

Note from Technophile: One cubic kilometre of hot granite at 250 degrees centigrade has the stored energy equivalent of 40 million barrels of oil. Australia has large volumes of identified high heat production granites within 3 to 5km from the surface. This represents a vast resource of clean energy that can potentially be tapped by hot dry rock geothermal technology.

Source: [Geodynamics]