This paper reports on the recent advancement of the GRANEX technology platform developed by our group for power generation from low-grade heat sources. The technology is particularly suited to applications involving geothermal power generation and waste heat recovery. By combining the concepts of heat regeneration and supercritical Rankine cycle into a unified process, GRANEX improves the thermal efficiency of the cycle and increases the net electrical output which can be recovered from a given low-grade heat source. The regeneration of the thermal energy in GRANEX is achieved through a novel heat regenerator invented and patented by our group in partnership with Granite Power Limited (GPL). Development of GRANEX dates back to early 2006 when a Research and Development Agreement was established between the University of Newcastle and GPL. In conjunction with a program of fundamental studies an applied program of work was undertaken for proof of concept and prototype development with the assistance of a REDI grant from AusIndustry (2007-2009). By 2008, a 1 kW prototype had been built and experimental trials of the system had been completed, demonstrating considerable advantages over conventional systems in terms of both thermal efficiency and power generation (about 40% improvement). This was followed by the design of a 100 kW pilot-plant in early 2009. The pilot-plant is currently under construction and is due to be commissioned by late November 2009.
2009 Australian Geothermal Energy Conference. Proceedings of the 2009 Australian Geothermal Energy Conference (Brisbane, Qld 11-13 November, 2009)