Scientists hope to drill 500 meter deep exploration wells in Dunedin volcano

A team of Dunedin scientists wants to drill two 500m deep exploration wells in the 11 million year old Dunedin volcano in search of crucial geothermal energy.

Dr Mike Palin, from the geology department at the University of Otago, said significant amounts of carbon-based fuels were burned in New Zealand and elsewhere to generate heat for buildings and manufacturing.

He and several other colleagues in the department of geologists were asking whether the residual heat from extinct volcanoes could be harnessed as a geothermal energy resource, “thus reducing carbon-based fuel consumption and consequent greenhouse gas emissions.”

Scientists hope to drill below the sedimentary rock layer to monitor any residual heat from the now solidified magma chamber below, from the area’s volcanic past.

If the test is positive, the heat could be captured by pumping water underground in a circuit and heating it again.

This is likely to eventually require deeper drilling.

The successful utilization of this geothermal resource, if it were of sufficient size, would have long-term economic benefits both locally and nationally.

In Dunedin, the main heat users were Dunedin Hospital, the University of Otago and the central business district.

“The reduction in fuel costs will translate into a direct economic benefit to them, as well as indirect savings to the central government through financing of health services and tertiary education,” said Dr. Palin.

The University of Otago and Dunedin Hospital already used some shared heating, and one possibility was that the new remodeled hospital could meet some of their heating needs from geothermal sources.

An exploratory well is expected to be drilled in central Dunedin and another in the Port Chalmers-Portobello area, perhaps at the university’s Portobello Marine Laboratory.

Dr. Marco Brenna is the scientific lead on the proposal, and Dr. Christian Ohneiser and Associate Professor Andrew Gorman are other members of the group.

The objective was to present tomorrow to the Ministry of Business, Innovation and Employment a concept proposal that seeks support for the $ 1 million project through MBIE’s Smart Ideas scheme.

MBIE would evaluate the proposal and indicate in March if it could be developed in more detail, Dr. Palin said.

Measurements obtained from drilling-related monitoring would also be used to generate a 4-D spatiotemporal geological model of the volcano and to determine the extent of the geothermal resource.

Dr. Palin described the geology group’s vision for the drilling proposal in a talk he gave on their behalf at a recent Otago Energy Research Center symposium.