Research on concentrating solar thermal systems at ANU

The large dish approach to solar concentrator systems offers the highest possible conversion efficiencies and justifies a higher capital cost per unit area. The Australian National University (ANU) has worked for many years on paraboloidal dish solar concentrators and demonstrated a 400 m² system in 1994. The commercialization of this technology has involved a re-design of the Big Dish concept for mass production. The new design is a 500 m² concentrator with 13.4 m focal length and altitude-azimuth tracking. It uses 380 identical spherical 1.17m × 1.17m mirror panels, which incorporate glass-on-metal laminate mirrors. Construction of a first prototype on the ANU campus began in the first quarter of 2008. The first on sun test was carried out on 29 June 2009. Initial optical analysis shows that operation of receivers with geometric concentration ratios of at least 2000 times is feasible. Developments to optimise the use of dish systems to drive direct steam generation and ammonia-based thermochemical energy storage are continuing. A new area of investigation is gasification of wet biomass in the form of algae, using supercritical water. Lab scale investigations show high levels of conversion and good kinetics and suggest that this process is suitable for application to dish systems.