Tiny turbine a testbed for hot rock
ATINY 1MW power turbine being delivered by sea to Australia this month may be the harbinger of a major, long- term shift in decarbonising baseload electricity delivery. The little turbine is being brought in by Geodynamics to power its Cooper Basin operations and the nearby remote central Australian village of Innamincka with geothermal energy.
Once the turbine is commissioned late this year, jokes Geodynamics chief executive Gerry Grove- White, the Innamincka pub will be able to boast it uses the world’s hottest non- volcanic rocks to serve the coldest beer.
The energy from the turbine will be tapping 250C heat in rocks 4km below the red desert sands using five million year- old water trapped in deep aquifers. The water will not be extracted — it will be brought up through one deep well and put back down through another. The wells are critical to Geodynamics’ plans to provide greenhouse gas emissions- free electricity to the eastern Australian power market.
Their depth and the hardness of the rock through which they pass created substantial problems for the company when its second well had to be abandoned, unfinished, a year ago, blocking access to the deep water reservoir before important pumping tests could be undertaken. The company’s share price fell, its foundation managing director left and the opportunity to obtain $ 75 million in project support from the Howard Government was lost. The Geodynamics board responded by spending $ 32 million to acquire Australia’s most advanced landbased drilling rig from the US, and relaunched its development program.
This year to date the news for Geodynamics has been increasingly good. Habanero 3 well has been completed to a depth below 4200 metres, shareholder Origin Energy has pumped in $ 105.6 million through a farm- in deal in the company’s South Australian licence area, and plans are progressing to build a 50MW demonstration plant ( and another nine 50MW modules).
Economists Brian Fisher and Anna Matysek of Concept Economics, in analysis for the Australian Petroleum Production & Exploration Association of the impact of the Rudd Government’s renewable energy target policy plus emissions trading, have forecast that the Cooper Basin development could be delivering nearly 3000 gigawatt hours a year to the market by 2020 — a fraction of the projected 74,000 GWh contribution from renewable energy but a large stride on a long road for Geodynamics.
Grove- White, who became chief executive of Geodynamics last August, is upbeat about the longer term prospects: he told a Committee for the Economic Development of Australia forum in Sydney last month that the company aims to have more than 1000MW of capacity in operation at the Cooper Basin site by 2020.
This will involve one of Australia’s largest onshore deep drilling programs. GroveWhite says the initial commercial development of 500MW will require use of six drilling rigs to sink 90 wells by 2016.
Looking further ahead, he is talking of the area’s heat mining being able to provide between 5000 and 10,000MW baseload capacity for the eastern States’ national electricity market, which provides more than 85 per cent of Australia’s power.
The existing baseload capacity for the NEM stands at 22,000MW, most of it fuelled by carbon dioxide- heavy coal turbines.
The Cooper Basin geothermal operation will have no greenhouse gas emissions at all.
By comparison, a 500MW conventional modern coal plant emits a total of about 15 million tonnes of carbon dioxide over a decade’s operations.
It is estimated that companies pursuing hot dry rock- based energy have now committed in licence arrangements with state governments to spending $ 800 million on the initial steps — a rise of about $ 230 million over 12- 18 months. The writer has provided advisory services to Geodynamics Limited
Upbeat: Gerry Grove- White