| Australian "Hot Rocks" Offer 26,000 Yrs of Power
AUSTRALIA: August 21, 2008
SYDNEY - Barely one percent of Australia's untapped geothermal energy could
produce 26,000 years worth of clean electricity, scientists said, as the
government announced a a A$50 million (US$43 million) project to help
develop the technology.
Australia is the world's biggest coal exporter with coal used to generate
about 77 percent of its electricity. 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 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.
Geoscience Australia has mapped the nation's geothermal energy, using
temperature recordings from decades of drilling by energy and exploration
firms, sometimes to a depth of five kms (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 told Reuters on Wednesday.
Budd said "hot rocks" needed to be 150 degrees Celsius to produce
electricity, which was achievable at a depth of one to five kms, noting
temperature rose 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 a small pilot plant
producing 10 to 50 megawatts of power, and A$80 per megawatt hour for a
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.
The government's geothermal drilling project will see different technologies
used at various locations around Australia to try and determine the best
technology for converting "hot rock" energy into electricity.
Ferguson said the first commercially viable geothermal power plants could be
in place within four to five years.
"Geothermal energy provides clean base-load power and is potentially a very
important contributor to Australia's energy mix in a carbon-constrained
world," he said.
Prime Minister Kevin Rudd won power last November in part by promising to
sign the Kyoto Protocol, which sets binding limits on emissions from
developed countries, and to cut emissions by 60 percent of 2000 levels by
2050. (US$1=A$1.15) (Editing by Sanjeev Miglani)
Story by Michael Perry
REUTERS NEWS SERVICE
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