What is Solar Cooling?

Solar Cooling is a technology which converts heat collected from the Sun into useful cooling for delivery to applications such as building space conditioning. In this process, solar heat is collected and is used by a thermally-driven cooling process, which generates chilled water or conditioned air for use in the building. Chilled water is not widely used for cooling in residential applications but is used extensively in commercial buildings.

This process is summarised in the graphic below.

Solar cooling is a technology with a number of variants which exist due to the availability of a number of components which can be used in the solar heat collection, thermally-driven cooling process and delivery stages. The configuration of these components can also be altered. Broadly, however, solar cooling can be categorised into Open Cycle and Closed Cycle systems. The technical aspects of solar cooling are discussed further in How Solar Cooling Works.

Solar cooling offers Australia an important opportunity to combat climate change by reducing the significant greenhouse gas (GHG) emissions generated by the electricity sector in servicing the residential and commercial building sectors. Solar cooling is uniquely suited to Australia because most of the population is located in subtropical or temperate regions which experience hot summers and relatively mild winters. Consequently, in Australia there is limited use for solar heat in buildings unless it can be used for space cooling.

Conveniently though, the maximum demand for space cooling typically coincides with the maximum availability of solar radiation (and therefore heat) for solar cooling, particularly in commercial buildings (Figure 2). This natural synergy between cooling demand and heat resource availability is ideal for solar cooling applications. Furthermore, some solar cooling technologies are capable of using diffuse radiation and have good storage capability - both of which can be of great significance on cloudy days.

The technical viability of this technology has been well established in a number of commercial-scale installations around the world, particularly in Europe. Despite this, solar cooling is a technology with many variants and no one approach has yet been found to be universally applicable. For these reasons there is a need to raise the profile of solar cooling in Australia, find solutions for Australian conditions and up-skill the local industry to rise to the challenge of developing and implementing effective solutions. The ausSCIG has been established to achieve these goals.