Australian researchers have succeeded in producing ‘supercritical’ steam. This breakthrough means that the sun could one day replace coal and gas to drive power stations or to boost the efficiency of solar thermal plants – if the government allows it, that is. Barbara Barkhausen reports from Sydney.
A world without CO2 emissions and coal-fired power plants. It sounds like a utopia, and yet it is one step closer to becoming reality. Australian researchers have show that the world does not need to burn fossil fuels to meet our energy needs. They used solar energy to generate hot and pressurised ‘supercritical’ steam, which could one day be used to drive even the most advanced power stations in the world.
Competing with fossil fuels
Alex Wonhas, Energy Director at Australia’s national science agency CSIRO (Commonwealth Scientific and Industrial Research Organisation) calls the production of ‘supercritical’ steam a game-changer for the renewable energy industry: “It’s like breaking the sound barrier; this step change proves solar has the potential to compete with the peak performance capabilities of fossil fuel sources.”
Instead of burning fossil fuels to produce supercritical steam, this breakthrough shows that power plants could instead use free, zero-emissions solar energy and still achieve the same result. ‘Supercritical’ solar steam is when water is pressurised at an enormous force and heated using solar radiation. The CSIRO Energy Centre, located in Newcastle just two hours north of Sydney, set a world record in May this year when it achieved at pressure of 23.5 megapascals (a measure of force per unit area) and temperatures up to 570 degrees Celsius.
Solar energy will cost less
‘Supercritical’ steam could not only replace fossil fuels, but it would even help bring down the costs of solar electricity. Commercial solar thermal power plants use what is called ‘subcritical’ steam, in which they operate at similar temperatures but at lower pressure. If these plants were able to move to supercritical steam, it would increase their efficiency and therefore reduce the cost of producing solar energy.
Although the breakthrough is significant, there is still work to be done before this technology is ready for commercialisation. But for CSIRO, it is now a race against time: The country is ideally suited to solar energy thanks to its sunny climate. And the science is advanced enough, too: The current success is not the first of its kind. Stuart Wenham and Martin Green from the University of New South Wales developed the first solar cell with 20 per cent efficiency in 1985, and CSIRO is currently developing printable solar cells.
Politics is a major obstacle
But renewable energy in Australia has fallen out of favour on a political level since Tony Abbott came to power last September. Abbott is a big supporter of the coal industry – which supplies around 80 per cent of Australia’s energy – and he has dismissed climate change as “absolute crap”. Abbott wants to abolish the carbon tax introduced by the previous government and reduce his country’s emissions by only 5 per cent compared with 2000 levels by 2020. And so while U.S. President Barack Obama has taken up the war against coal on the other side of the planet and wants to force power plants to reduce their CO2 emissions by 30 per cent compared to 2005 levels by 2030, Abbott has publicly stated on the international stage that he would choose the Australian economy over climate change without a moment’s hesitation.
Since taking office, Abbott has shown this more than once: He abolished the country’s climate commission, dismissed 500 scientists from CSIRO and cut renewable energy from the agency’s budget. And yet the latter is precisely what was used to support the ‘supercritical’ steam research programme in the first place.
Photo credit: CSIRO