SOLAR power towers complete with chemical reactors will use the energy and heat of the sun to make metals from minerals in the low-carbon, high-tech world of the future.
Visonary scientists at the University of Adelaide are teaming up with experts from overseas to develop the solar reactors, which can also produce solar fuels such as gas or diesel.
Professor Aldo Steinfeld from ETH Zurich, who is in Adelaide for the 8th Asia Pacific Conference on Sustainable Energy and Environmental Technologies, said the technology was proven.
He said he wanted to adapt concentrated solar power towers currently used in Spain and the US to heat water, produce steam and drive turbines.
“On top of the tower we will place a chemical reactor,” he said.
“This chemical reactor will be making metals out of minerals. We can supply concentrated solar energy for these processes.”
Temperatures above 1000C are needed in the production of metals such as iron from the mineral hematite (1500C) or zinc from zinc oxide (1300C).
Coal typically fuels these processes, but parabolic mirrors can instead be used to concentrate the solar energy from the sun.
“This process has the potential of saving up to 80 per cent of emissions because solar is providing the heat,” Professor Steinfeld said.
Robbie McNaughton from the CSIRO Energy Centre in Newcastle said there was great hope for solar power to replace other sources of electricity and heat in the future.
“CSIRO is home to Australia’s largest solar thermal research hub, located in Newcastle,” he said.
“The facility houses two fields of heliostats, or mirrors, capable of collecting a combined 1.5MW of solar energy and able to heat solar receivers to temperatures above 1000C.
“Current projects at the CSIRO include research into solar fuel production, solar air turbines, high temperature steam generation and advanced materials for storing solar energy – to enable electricity to be produced at night.”
University of Adelaide director of the Centre for Energy Technology, Professor Gus Nathan, said it was likely to be another 15 years before solar fuels become a commercial reality and perhaps twice as long before we would see metals made on top of solar power towers.
But, he said, it could happen much faster if industry was ready to invest big sums of money in the developing technology.
“Most people are aware you can use solar energy to generate electricity, but there is much less awareness of the fact you can use concentrated solar energy to do a lot of other things,” he said.
“One of them is to produce fuels of lower carbon intensity and another is to do the heat-treating of minerals and metals with the heat from concentrated power.
“They’re both great opportunities. They won’t come overnight, we’re talking about a 50-year transition, but they can play an important role in that time.”