“Win – Win” situation between landowners, government and the mining industry in the South Pacific

Project Leader: Dr. Holger Sommer

School of Geography, Earth Science and Environment

Faculty of Science, Technology and Environment

http://www.geothermalcities.com & http://www.holgersommer.de

 

About the project:

This project develops a clean geothermal power solution for the South Pacific.

The target is to integrate multiple uses of natural geothermal heat for electric power, cooling solutions and providing fresh water to local communities. Another important target is facilitating environmentally friendly mining operations.

 

Mining

Gold, Copper and Bauxit ore deposits are very common in the South Pacific region and are of high economic interest. Yet from a societal aspect they currently return very little to support the infrastructure of these islands. This is mainly due to the fact that the high cost of mining is borne by multinational companies with little connection to local communities. Costs are driven by the immense amount of energy needed for operations. For example, the Vatukoula Gold mine in the northern part of Viti Levu needs 20 000 litres of fuel per day for mainly rock crushing. Not only is this very expensive, it is also environmentally problematic because of the high CO2 production caused by burning of the fuel. Another undesired side effect of conventional mining operation is that after the exploitation is terminated, the infrastructure is of little use to local citizens and communities resulting in high rates of unemployment and barren and desolate landscapes.

Geothermal Cities

This project develops an international alliance for implementing the use of natural geothermal heat as the main energy source for industrial and domestic use to convert the above described problems into a “Win-Win” situation for the development of the South Pacific. If successful, this initiative could become a showcase for the United Nations for enabling a cleaner developing world.

 

Possible Geothermal Industries in Vanua Levu:

  • Gold and Copper Mines
  • A lumina Refinery

Needs to operate a Alumina Refinary:

  • Bayer Process needs 150-170°C hot water Water needs Waste Heat in evaporation ponds, 4.5 Gl/year evaporation

Geothermal provides:

  • Direct Heat for the Alumina Production Waste Heat is converted to fresh water through Desalination

The Use of Geothermal Energy in Vanua Levu:

Part 1: The Resource

 

Part 2: The Technology

 

  • Geothermal Power Plants
  • Geothermal Air Conditioning
  • Geothermal Desalination

Part 3: The Application

 

  • Vanua Levu
  • Vision: Geothermal Villages,
  • Cities & Industries

 

Natural Recources for Geothermal Energy in Vanua Levu:

Human Need of Natural Energy Recources

  • Heat as a commodity

Geothermal System

  • Green and Sustainable Energy

Methods:

We present a new environmentally friendly strategy for the mining industry, the landowners, the communities and the governments of the South Pacific Islands. All of the South Pacific islands are geologically extremely young. Consequently, the crust is very thin and hot, as evidenced by numerous hot springs at the surface in most of the South Pacific Islands. The water from those hot springs can be analysed which delivers information about the rock units being in contact with the heat source. The analyses contain information on the traces of all compatible and incompatible elements which give information on the pressure and temperature conditions of the rock forming minerals contained in geothermal waters. From the pressure, one can calculate the depth and temperature,

Another important information is obtained from the calculations using the incompatible elements. 

This will give the first indication on the commercial viability of potential mine operations. That is due to the fact, that Gold and/or Copper is dissolved in the circulating water and therefore first assumptions can be made if it is worth to drill or not. If the chosen location is found to be attractive for mining, the next question to be answered is: Where can one obtain the energy to run such a mine? Presently, a vast amount of fossil fuel is required to run generators to produce tens to hundreds of MW capacity, which makes the location dependent on an available energy source.

The remote location often makes this an unprofitable solution, notwithstanding the negative environmental impact of burning fossil fuel. It would make more sense to use geothermal power.

Commercially attractive clean geothermal solutions have been developed. The Australian company Newcrest has, for instance, written high profits for their gold mine on a volcanic island in Papua New Guinea (Lihir), owing to displacing heavy fuel generators by a geothermal power plant. This example shows that it is not only feasible but, highly profitable to use a geothermal energy source. For most of the hot springs in the South Pacific region the water is at boiling point when it reaches the surface, this implies that the bore holes must typically not be deeper than 600m to get the maximum power output of the plant. The waters are also often alkaline because most islands are made up of silica undersaturated rocks. This makes the energy source very attractive for energy extraction as cheap carbon steel can be used for the powerplant.

Thus, it is important for the local industry to assess this geothermal potential in a pre-feasibility study. This brings this project into the societal focus as it could contribute directly into the

hands of the local landowners, communities and governments. An added benefit could be that after mining operations are completed, the geothermal power plant is left and could be used to supply power to the local communities. This implies that at this stage after the operation of the mine has finished post mining operations can start a new clean industry. Geothermal power plants can provide power on a human time scale for generations and the electricity from the power plant is proven to be of high benefit to the local economy. The new geothermal power station by Mighty River Power near Kawerau in New Zealand is an excellent example where a commercial electricity provider is returning significant profits to the traditional land owners with positive effect on education and infrastructure.

Outcomes and Impacts

From the scientific point of view, we will analyse water samples from 45 different hot springs in Vanua Levu. This will be done at different Labs worldwide, by Dr. Holger Sommer, collaborators and numerous postgraduate and bachelor students from Earth Science at USP and worldwide.

First: Incompatible elements as Cu and Au will be measured to identify a possible ore deposit.

Second: Traces of elements like Mg, Fe, Na, Ca, K, Al and Si will be analysed to recalculate the

rock units with which the analysed water was in contact with which is important to find out about the depth of the circulating water in the Earth‛s upper crust and is therefore important to deduce how deep the drill holes have to be.

Third: These first measurements will be completed by in-situ measurements from researchers based at the University of New South Wales, Australia on a multidisciplinary base.

 

Partners and Rules:

a) Dr. Holger Sommer, SGESE, FSTE, USP - MinPet, Fluid Rock Interaction, Ore deposits, Geothermal Energy

b) Prof. Dr. Klaus Regenauer-Lieb, University of New South Wales (UNSW), Australia - Geodynamics, Geothermal Energy

c) Prof. Elisabeth Holland, PaCE-SD, USP - Climate Change, Suistanable Energy

d) Dr. Bibhya Sharma, SCIMS, FSTE, USP - Numerical Modelling

e) Dr. Sushil Kumar, SEP, FSTE, USP - Geophysics

f) Dr. John Lowry, SGESE, FSTE, USP - GIS

g) Dr. Jeremy Hills, IMR, FSTE, USP - Social Studies and Development

h) Prof. Mike Petterson, SPC Geoscience Division - Geology

i) Selina Leo, SLS Resource Group, Suva, Fiji - Industry

j) Neil Kumar, SGESE, FSTE, USP - Assistant