Keeping cool using the summer heat

Staff Writers
Tuesday, 27 January 2009 09:33

Science - Energy

Scientists at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) are researching ways to use the sun’s energy to cool homes and offices.

Harnessing the sun’s warmth to power air conditioning systems is the goal of the CSIRO’s Energy Transformed Flagship group, with the group’s leader, Dr Stephen White saying that significant greenhouse gas savings can be achieved by using the sun’s energy.

Dr White says solar cooling utilises heat from solar thermal collectors to generate cooling for building air-conditioning, consuming less electricity when compared to a conventional mechanical air conditioner and lower electricity consumption resulting in lower greenhouse gas emissions.

"Most conventional mechanical air conditioners use high-emission electricity derived from fossil fuels to provide the energy to compress a refrigerant and cool a building. This typically accounts for 20-30 per cent of building energy consumption and greenhouse gas emissions.

"The solar cooling technology we are developing directly uses the natural heat from the sun to power a thermally-driven cooling process," he says.

According to Dr White, “while using heat to cool sounds like a strange concept, the technology we are developing is able use that heat in conjunction with an absorbent material – or desiccant – to dehumidify and cool air. This new type of desiccant cooling promises to be simpler and more cost effective than absorption chillers."

Dr White says sunshine is “perhaps the nation's most abundant renewable resource” with Australia experiencing the highest incidence of solar radiation in the world. Coincidentally, on those days when the sun is shining the brightest, demand for air conditioning is at its highest, according to Dr White.

"In this way, solar cooling has the potential to reduce peak demand on the electricity grid by reducing the amount of electricity that is required to meet those air conditioning demands on the hottest days of the Australian summer."

Dr White said that as the technology develops it is likely to make an important contribution to the development of future zero-emissions buildings.