Solar air-con in action

CSIRO has helped develop a solar-powered air-conditioning system for use at Stockland Wendouree Shopping Centre in Ballarat, Victoria, and says it is a shining example of how to use the sun to cool buildings — making the most from the Australian climate.

Given that commercial spaces use around 60% of total energy consumption on heating and cooling, CSIRO designed a system using breakthrough technology to achieve better energy efficiency.

Using concentrating solar thermal (CST) technology, the system produces its own heat energy to power the air conditioning, which results in less cost to the business. The development was assisted by funding from the Australian Renewable Energy Agency (ARENA) and is being jointly managed by CSIRO, Stockland Group and NEP Solar.

What makes this technology so cool?

The technology comprises a closed-loop system that uses two ‘desiccant’ wheels to remove moisture from the air, acting as a dehumidifier. A high-temperature wheel uses solar heat for regeneration while the low-temperature wheel functions without any external heat to deliver greater efficiency. An indirect evaporative cooler reduces the temperature of the dehumidified air without altering the moisture content of the air stream.

NEP’s solar troughs are installed on Stockland Wendouree’s rooftop, trapping heat from the sun. This heat is stored in a thermal oil tank to deliver space heating and cooling. The roof space required for this cutting-edge technology can be 40% less than a traditional single stage desiccant air-conditioning system. It also allows humidity-controlled fresh air into the building to deliver temperature comfort.

Concentrating on an efficient future

CSIRO Energy Director Peter Mayfield is pleased with the early results.

“Our energy research is driving down costs of renewable technologies, accelerating the transition to a lower-emissions future. We are pioneering new technologies and this project is a world-first demonstration of a desiccant air-conditioning system using roof-mounted concentrating solar thermal collectors to drive energy efficiency,” he said.

ARENA CEO Ivor Frischknecht sees huge potential.

“It has the potential to further improve the efficiency of solar thermal energy systems and storage to provide clean and reliable heating and cooling in commercial buildings,” he said.

CSIRO will continue to assess and monitor the technology for the next 12 months to establish long-term commercial operations and further investment as part of our commitment to creating a low emissions future for Australia.