Pilot Project A+B: Geothermal Refrigeration and Freezing Facility at Savusavu and Waikatakata Hot Spring, Natewa

 

Project A is on-grid Project B is off-grid. The projects cover a central refrigeration facility for Savusavu and off-grid for Natewa Village and surrounding villages (1000 people). Project A has a higher economic potential, whereas project B is of higher social humanitarian relevance to improve the health and living conditions. There is no electricity and chiller available within 90 minutes’ drive of Natewa village.

 

In Partnership with Research Agencies, Industry and a local NGO

University of South Pacific (USP)

Dr Jito Vanualailai - Research Office, Assoc. Prof. & Director of Research

University of South Pacific (USP)
  • Dr. Holger Sommer, SGESE, FSTE – Petrology
  • Prof. Elisabeth Holland, PaCE-SD, - Climate Change, Sustainable Energy
  • Dr. Bibhya Sharma, SCIMS, FSTE - Numerical Modelling
  • Dr. John Lowry, SGESE, FSTE - GIS
  • Dr. Jeremy Hills, IMR, FSTE - Social Studies and Development
  • Prof. Mike Petterson, SPC Geoscience Division - Geology
  • Neil Kumar, SGESE, FSTE- Assistant
Industry  
Representative for Natewa
  • Dr Graham Wragg
  • Nambu Conservation Trust
  • Natewa Village
  • Vanua Levu
University of Western Australia Prof. Hui Tong Chua – HVAC
UNSW (School of Petroleum Engineering) Prof. Klaus Regenauer-Lieb – Geothermal Energy

 

Overarching Aim

This project develops a clean geothermal power solution for the South Pacific. The ultimate target is to integrate multiple uses of natural geothermal heat for electric power, cooling solutions and providing fresh water and other direct heat uses to local communities. This pilot project is designed as the first step using a comparatively low risk direct heat technology. The project involves an international alliance for implementing the use of natural geothermal heat as the main energy source for industrial and domestic use. If successful, this initiative could become a showcase for the United Nations for enabling a cleaner developing world.

The Technology

Geothermal energy derived from natural hot springs and used for direct heat applications (heating ventilation and cooling) has enormous potential to reliably provide base load capacity, and represents a state-of-the-art renewable approach to cooling cities and small villages.

The technology is based on replacing electrically driven vapour compression chillers with heat driven sorption chillers (refrigerator/freezer). The technology is scalable up to 100’s of MW thermal cooling capacity to service HVAC needs for large commercial buildings, including universities, hospitals, hotels, airports, data and shopping centres. Hot geothermal water as the principal power source is the most energy efficient means of heating and counterintuitively also cooling.

The refrigeration technology can be illustrated schematically as identical to its electrically driven sibling, the main difference is the use of a thermal compressor (thermochemical) instead of an electric compressor. A small source of electricity is still required for circulating the chemicals but the pumping power is minor and can be provided by an off-grid PV system.

The technology can be described as a thermo-chemical heat pump. It should, however, not be confused with a geothermal heat pump, also known as ground source heat pump.

Although the thermo-chemical pump can be used for the same purpose it does not require electricity for the compressor but uses heat instead. It is hence superior in displacing electricity needs and may be considered the most efficient thermal direct Heating, Ventilation and Air Conditioning (HVAC) system.

Various chemicals can be used for the thermo-chemical evaporation cycle. At the lowest temperature solid compounds such as silica gel or zeolites can be used to adsorb and evaporate distilled water. Hence these chillers are called Adsorption Chillers. At higher temperature closed loop Lithium-Bromide or Ammonia-Water solutions are used to absorb and evaporate distilled water.

Hence these chillers are called Absorption Chillers.

The Full  Project description PDF file can be downloaded here