Solar drives air-con efficiency

Rooftop concentrating solar thermal collectors power air-conditioning systems at Stockland Wendouree
Rooftop concentrating solar thermal collectors power air-conditioning systems at Stockland Wendouree

CSIRO has unveiled a solar-powered air-conditioning system to cool Australian commercial buildings.

Operating at Stockland Wendouree Shopping Centre in Ballarat, Victoria, the energy efficient system uses concentrating solar thermal technology to produce heat energy which, in turn, powers the air-conditioning system.

The Australian Renewable Energy Agency (ARENA) provided $520,000 to support the $1.2 million project, jointly managed by CSIRO with Stockland Group and NEP Solar.

The system addresses the high energy consumption of large commercial spaces such as shopping centres and hotels due to their heating and cooling energy requirements – around 60 per cent of total energy use.

The closed-loop system uses two ‘desiccant’ wheels to remove moisture from the air, acting as a dehumidifier. A high-temperature wheel uses solar heat for regeneration while a low temperature wheel functions without any external heat to deliver greater efficiency on a commercial scale.

CSIRO energy director Peter Mayfield said research such as this 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,” he said.

The air-conditioning system is powered by NEP Solar’s trough collectors with heat stored in a thermal oil tank.

The roof space required for the solar air-conditioning technology can be 40 per cent less than a traditional single-stage desiccant system.

Solar heat-driven desiccant air-conditioning systems can provide humidity controlled fresh air into the buildings and is expected to significantly reduce HVAC electricity usage for commercial buildings.

CSIRO will continue to assess and monitor the technology for the next 12 months to establish long-term commercial operations.