Solar Air Conditioning: Opportunities and Obstacles for Austalia (2005)

This report was produced as an outcome of Warwick Johnston’s George Alexander Foundation/International Specialised Skills Institute fellowship for Solar Air Conditioning.

It looks at the commercially available solar air conditioning technologies, and those under development at that time. It assesses the areas of Australia that each technology is most appropriate, and assesses the economic viability of solar air conditioning in 2005.


Solar Air Conditioning – Opportunities and Obstacles for Australia – 2005


1. Executive Summary
What is Solar Air Conditioning?
Solar air conditioning is the application of solar thermal energy (heat) to production of
conditioned air through a thermally-driven refrigeration process.
Why is Solar Air Conditioning Useful and Necessary for Australia?
Australia has a very sunny climate, with high demand for air conditioning. Air
conditioning’s impacts upon the electricity network and the environment threaten to affect
our quality of life. On hot summer’s days, the electricity grid increasingly faces the danger
of overload due to air conditioner use, which would cause essential service disruption and
severe economic impact. Associated with air conditioning’s high use of energy is
significant environmental pollution, namely in the form of greenhouse gas emissions –
with the resultant climate change impacting not only upon our environment, but also our
health and productivity.
Of the many ways of individually addressing air conditioning’s impact upon the grid and
environment, solar air conditioning (SAC or solar cooling) is one of the few solutions that
provides cooling and addresses peak loading, and does so with reduced environmental
Solar Air Conditioning Fellowship and Investigative Study
At present, there exists little awareness or understanding of solar air conditioning within
Australia. A fellowship was undertaken to address solar cooling related skills deficiencies,
with the intention of raising awareness, developing understanding, and providing a
framework for a future Australian solar air conditioning market. This report forms one such
dissemination activity.
Benefits of Solar Air Conditioning
The fellowship resulted in the understanding that solar air conditioning:
• can contribute to Australia’s cooling requirements
• can also provide heating of living areas and domestic hot water
• can alleviate pressure upon the electricity network
• can provide environmental benefits
• can address the particularly high cooling demand of existing building stock
• can already be applied to commercial buildings and industrial applications, and
will soon be readily applied to residential buildings
• has already successfully demonstrated itself in Europe, the USA, and Asia
• presents interesting opportunities of note to Australia
o Application of rejected heat to swimming pools
o Incorporation of biomass or cogeneration to deliver greenhouse gasminimal
• holds particular promise in tropical environments, and therefore presents a
domestic and export opportunity
– iii –
Barriers to Implementation
There are barriers to be overcome if solar cooling is to live up to its market potential and
supply a significant part of Australia’s cooling and heating needs. The barriers relate to
ignorance, market factors, social factors, buildings’ characteristics, and environmental
impact. However, the largest barrier at present is economic. Although a simple
comparison of SAC and conventional A/C system prices is complex to perform, the
economics of solar cooling are generally unfavourable when compared to conventional
cooling systems. This is due to:
• Cost of solar collector
• System complexity
• Low energy prices in Australia because of cheap fossil fuel and unaccounted
environmental costs
• Cross-subsidy for air conditioning, by which all energy users pay for electrical
network infrastructure required to satisfy installation of new air conditioners,
with a 2kWe air conditioner, which may cost $1000, requiring $6000 of
• Lack of economic reward for producing or reducing energy during times of
peak load
• Lock of incentive for building owners to install energy efficient equipment in
leased buildings
Overcoming Barriers
Many of the aforementioned economic barriers are also faced in Europe, and are
presently being addressed through research, development, and demonstration systems.
However, addressing the market-related barriers requires some governmental
intervention. The following measures improve the economic viability of solar air
• To reduce collector costs, increased production volumes can be stimulated by
further subsidies
• To simplify system design, standardised modules are being produced
• Cross-subsidies could be addressed by making air conditioner buyers pay the
costs of infrastructure upgrades thus necessitated by their air conditioner use
• The peak load effect would be reduced by passing on peak costs to the user
(interval metering), thereby also encouraging uptake of alternate cooling
• Building owners could be encouraged to install energy efficient systems by
providing a market recognition mechanism such as an ‘energy passport’
• Environmental costs that are presently excluded from energy prices could be
addressed through a carbon tax or trading mechanism
Such measures would benefit solar cooling, as well as other Australian industries,
particularly those related to sustainability in cities.