Solar cooling: Perspectives in Australia

A paper by P. Kohlenbach and M. Dennis1 presented at the 9th IIR Gustav Lorentzen Conference on Natural Refrigerants in Sydney gave an outlook and future perspectives on solar cooling in Australia, focusing on a comparison between the current potential energy and greenhouse gas savings in photovoltaic (PV) vapour-compression systems and solar thermal cooling with an absorption chiller and a grid-connected reference chiller. It was found that under current economic conditions and given assumptions, a solar thermal cooling system had a lower lifetime cost than a PV-based system. However, both had higher lifetime costs than conventional grid-connected systems. A sensitivity analysis on electricity prices showed that solar thermal cooling was more economic than PV-based cooling under a AUD 0.28/kWhel but the PV system offers cheaper cooling at electricity prices exceeding AUD 0.54/kWhel. However, solar systems become more economic than conventional systems for electricity prices above AUD 0.67/kWhel while greenhouse gas emissions were found to be the lowest for the PV-based system, due to the excess power generated over the system lifetime and the solar thermal system saves around 75% of the emissions of the conventional system. The residential air-conditioning market in Australia is around 800000 units per year and has increased significantly over recent years, since in 2006, 70% of Australian households had air conditioning (35% in 2000). The combination of good solar resource and a large air-conditioning market seems like a perfect match for solar cooling and refrigeration applications. However, solar cooling remains a niche technology because of economic and technical market barriers (low electricity prices, lack of trained staff, etc.) 1. P. Kohlenbach and M. Dennis: Solar Cooling in Australia: The Future of Air-Conditioning? Purchase the proceedings of the Sydney event: