This project aims to develop and commercialise a roof-mounted hybrid solar concentrator PV/thermal system that cost effectively delivers solar heating, cooling and electricity.
Lessons learned include solar concentrator cells being efficient up to 30 suns; hybrid beam splitter receivers can lead to cooling fluid boiling at temperatures above 130 degrees C; and using interference filtering (Dichroic filters) for short wavelength filtering of the incident sunlight proved a technically feasible solution although prohibitively expensive for large scale receiver designs.
Mirrors which absorb too much of the sunlight (more than 5%) can harm the overall performance of the collector and geometric considerations are also important as shading and blocking (particularly of the concentrated light) can adversely affect system performance.
In addition, a two stage desiccant air-conditioner that uses atmospheric pressure superheated steam at 150°C to regenerate the desiccant wheel in the high temperature stage has been designed. The primary advantage of the two stage design is the increased thermal efficiency in comparison to conventional single stage desiccant air-conditioning systems. Commercial viability of a 2-stage desiccator has been considered in relation to several potential sources of heat.
This ANU project aims to develop and commercialise an improved roof-mounted hybrid solar concentrator PV/thermal (CPVT) system to maximise the utility of solar energy conversion for the cost-effective delivery of heating, cooling and electricity that is suitable for installation on domestic, commercial and industrial buildings.
Improvement in efficiencies of CPVT systems and design of a high efficiency desiccant air-conditioning system using heat to achieve thermal efficiency close to double that of conventional systems.
The key innovation of the project is the use of spectral splitting of sunlight to improve the overall efficiency. During the course of the project two thermal receivers were successfully developed at ANU and RMIT. These were integrated with PV receivers developed and supplied by ANU and mounted on the two different concentrator platforms at ANU and RMIT. In addition, novel cooling technology that takes advantage of the thermal output of the system was developed by CSIRO.
The key benefit of the project remains the large amount of information that has been generated which is now available to others interested in hybrid energy systems. The skills that have been developed by students and staff in terms of modelling, characterisation, analysis, and knowledge of solar systems in general, are available to other solar projects. The commercial options for the project were undermined by the unforeseen significant reduction of cost in competing solar technologies, particularly PV which occurred during the course of this project.
In addition, a two stage desiccant air-conditioner that uses atmospheric pressure superheated steam at 150°C to regenerate the desiccant wheel in the high temperature stage has been designed.