Cooper Basin geothermal energy facts

Cooper Basin geothermal
energy facts

  • Enough usable heat energy to replace 50 billion
    barrels of crude oil
  • Will cost only four Australian cents per kilowatt per hour to produce
    electricity
  • Geysers are sources of green power
  • Many easy-to-tap hot rock reefs in New South Wales identified

    THE FEW
    engineers who recently saw super heated water explode into a geyser of steam
    out of the red dirt of South Australia’s remote Cooper Basin said it screamed
    so loudly their ears hurt.

    But the
    weird sight, a plume of steam shooting briefly into the sky in the vastness
    of an empty desert, accompanied by maybe the loudest sound ever heard across
    its mirage-rippled wastelands, may have announced breakthrough in clean,
    renewable energy.

    A big step closer


    It represented
    a big step closer to the goal of Australian firm Geodynamics Limited, to
    tap into the natural heat stored in vast beds of underground granite and
    use it to generate electricity.

    The company
    says there is enough usable heat energy in a 1000 square kilometre section
    of the rocks to replace 50 billion barrels of crude oil — or around 12 times
    as much oil as there is in the country’s largest proven oil reserves, in
    the north west shelf off the tip of Western Australia.

    The hope
    is the project can help solve the dual crises of shrinking oil supplies
    and greenhouse gas emissions. Dr Bertus de Graaf, Geodynamics managing director,
    says the lode of hot rocks under the Cooper Basin is the largest resource
    of its type known in the world, other than beneath volcanoes.

    ‘(These
    rocks) are a reef of granite trapped in the upper crust that makes up the
    continental plate in which small amounts of radioactive elements including
    thorium and potassium have been releasing heat as they decay over millions
    of years,’ he said.

    Wet geothermal
    energy has been used in Iceland and New Zealand where steam from hot springs
    are used to drive the turbines in power stations. But hot dry rock or HDR
    geothermal energy has proven far harder to tame, even though the principle
    is simple and has been the subject of research in dozens of countries for
    many years.

    After two
    years of drilling holes up to 4.4 kilometres deep Geodynamics is now able
    to pump cold water down into the granite reef where it becomes superheated
    and blasts its way back to the surface through a return shaft.

    According
    to the engineers, about 75 per cent of the heat in the hot water was lost
    as predicted when it exploded into steam out of the exit valve.

    However enough
    energy was captured by a heat exchanger to satisfy the needs of a future
    power station.

    Pilot power
    station


    Geodynamics’
    next step is to hook up a pilot power station and prove that part of power
    generated can be used to drive the water back into the subterranean heat
    source.

    Dr de Graaf
    believes it will cost only four Australian cents per kilowatt per hour to
    produce electricity from the Cooper Basin site, or about the same as the
    cost in Australia for getting the energy from coal and natural gas.

    If the pilot
    plant works as planned in the next year or so the company will sink 16 injection
    and 21 extraction holes into a seven square kilometre section of the lode
    to build a non-polluting power station generating 275 megawatts.

    To put this
    in perspective, the state of South Australia consumes 1500 Megawatts in the
    cool months and tries to draw 3000 Megawatts each scorching summer, when the
    only large city, Adelaide, turns its air-conditioning up to maximum.

    This causes
    widespread `brown outs’ because the state’s generating capacity is about 2700
    Megawatts.

    Geodynamics
    has already identified other comparatively easy-to-tap hot rock reefs in
    New South Wales, ironically beneath the richest coal fields in Australia,
    and in parts of Queensland and believes many more lodes await discovery in
    Australia and other parts of the world.

    Dr de Graaf
    says HDR is the only form of non polluting renewable energy capable of providing
    the power required by heavy industry and major cities, as it doesn’t suffer
    from the variability and minuscule efficiency of solar and wind power.

    If the screaming
    geyser of the Cooper Basin gives up its energy as cost effectively as its
    backers believe, they stand to become very rich as well as very green power
    brokers.

  • Source : www.hindu.com