Control Technologies International Limited (CTI) has been involved in the renewable energy research and development sector for many years after the CSIRO (Commonwealth Scientific & Industrial Research Organisation) appointed CTI to develop a thermal storage system utilising common salt or sodium chloride as the storage medium. Challenges such as the enormous thermal expansion that takes place while the salt is still in its solid state and the poor thermal conductivity were overcome. This technology has been retained by the CSIRO for further development.
Using parabolic dishes is a well-tested approach to concentrate solar radiation, and was an early experimental tool at many locations worldwide. The optical efficiency of parabolic dishes is considerably higher than that of a trough, lineal fresnel reflector (LFR) or power tower systems because the mirror is always pointed directly at the sun, whereas the trough, LFR and power tower have a reduction in projected area due to the frequent low angle of incidence of the solar radiation. The higher optical efficiency of parabolic dishes (which ultimately translates to a higher efficiency of conversion of sunlight to electricity) has always been partially offset by their capital cost. The cost per installed megawatt (MW) has always been higher than that of other non dish systems. It is from this approach that CTI started developing a new type of solar concentrator, one that would drastically reduce the cost per MW associated with older forms of solar technology.