Geothermal energy could power New Zealand

"Scientists conservatively estimate that deep geothermal resources in the central North Island could provide 10,000 megawatts for over 100 years for New Zealand," said GNS Science Senior Geothermal Scientist Greg Bignall, a convenor of the Taupo workshop.

"This would satisfy all of New Zealand’s current electricity demand, which is generated from a capacity of 9,000 megawatts," Dr Bignall said.

"But to achieve this there are a number of engineering and scientific challenges to overcome as conventional technologies would be pushed beyond their limits to extract fluids from such depths. Currently there is no satisfactory way of handling geothermal fluids that are 400 degrees Celsius."

Ground-breaking science, innovation and engineering would be needed for successfully drilling into these deep, very hot environments.

Scientists have a goal of drilling a deep well by 2014, and international collaboration developed through events such as the workshop in Taupo this week will help in building partnerships needed to achieve this.

"This is an ambitious goal and we will be operating beyond the capabilities of present geothermal science and technology. We are excited about the prospect of building on New Zealand’s industrial geothermal experience and government-funded geothermal research.

"New Zealand’s geothermal energy industry is held in high regard internationally and the deep-drilling initiative will reinforce New Zealand’s position as a leader in geothermal science and enegineering."

All of the country’s current electricity demands could be met by deeper boreholes tapping into hotter geothermal energy, scientists say. Conventional geothermal energy comes from boreholes up to 3km deep, tapping fluids up to 300 degrees, and providing about 13 per cent of the country’s total electricity. But by drilling to depths of about 5km and tapping even hotter fluids, the energy output from geothermal resources could increase dramatically.

"Scientists conservatively estimate that deep geothermal resources in the central North Island could provide 10,000 megawatts for over 100 years which would satisfy all of New Zealand’s current electricity demand, which is generated from a capacity of 9000 megawatts," said GNS Science senior geothermal scientist Greg Bignall.

"New Zealand’s geothermal energy industry is held in high regard internationally and the deep-drilling initiative will reinforce New Zealand’s position as a leader in geothermal science and engineering."

There were a number of challenges to overcome as there was currently no satisfactory way of handling geothermal fluids that were 400degC, Dr Bignall said.

Scientists want to drill a deep well by 2014 and the workshop this week, called Hades: Hotter and Deeper Exploration Science, aims to build partnerships needed to achieve this.

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