August 20, 2008

Australia Intends To Harness Clean Geothermal Energy

Australian government officials announced on Wednesday a new plan to convert geothermal energy into baseload energy.

The A$50 million (US$43 million) project is based on scientists' estimate that just one percent of the nation's untapped geothermal energy could generate clean electricity for 26,000 years.

"Geothermal energy which is sometimes known as hot rocks has got a huge potential for Australia, both as a solution to climate change and in terms of national energy security," said Resource Minister Martin Ferguson.

To produce power from geothermal energy, water is pumped below ground where it is heated and the heat energy used to generate power.

Currently the world's biggest coal exporter, Australia uses coal to generate some 77 percent of its electricity.

However, the country has set a goal of 20 percent renewable energy by 2020.

The Australian government's Geoscience Australia organization has mapped the nation's geothermal energy, using temperature recordings from decades of drilling by energy and exploration firms, sometimes to a depth of three miles.

A total of 5,722 petroleum and mineral boreholes across Australia were used to generate the map.

"One percent of reserves would produce 26,000 years of energy supplies," Geoscience's Anthony Budd said.

Hot rocks found at a depth of one to five kms would reach the 150 degrees Celsius needed to produce electricity.

Budd said temperatures would rise deeper into the earth's crust.

An Australian Geothermal Energy Association report this week forecast it could potentially produce 2,200 megawatts of baseload power by 2020, adding that represented up to 40 percent of Australia's 2020 renewable energy target.

The association estimated A$12 billion would need to be invested to develop the 2,200 megawatts of power, but added the cost of generating electricity would fall to acceptable levels by the time commercial projects were up and running.

It estimated it would cost A$120 per megawatt hour from small pilot plant producing 10 to 50 megawatts of power, and A$80 per megawatt hour for large scale plant of 300 megawatts or greater.

"The upper cost boundary will decline over time because the level of uncertainty is expected to narrow as the industry grows. This cost is expected to be lowest cost of any form of renewable or low emissions energy," it said.

"We could now see Australia's first commercially viable geothermal power plants in place within four to five years," said Ferguson.

Australia produces about 1.5 percent of the world's carbon emissions. Its reliance on coal for generating electricity makes it the world's biggest per-person polluter, with five times more emissions per head than China.

"Geothermal energy provides clean base-load power and is potentially a very important contributor to Australia's energy mix in a carbon-constrained world," said Ferguson.


On the Net: