Our solar team sets a hot and steamy world record

The run of sunny weather we’ve had in south-eastern Australia over the last few weeks has been breaking quite a few records – and not just on the weather charts.

A team of solar thermal engineers and scientists at our Energy Centre in Newcastle have used the ample sunlight flooding their solar fields to create what’s called ‘supercritical’ steam – an ultra-hot, ultra-pressurised steam that’s used to drive the world’s most advanced power plant turbines – at the highest levels of temperature and pressure EVER recorded with solar power.


The heliostat array, as viewed from Solar Tower 2.

They used heat from the sun, reflected off a field of heliostats (or mirrors) and concentrated onto a central receiver point to create the steam at these supercritical levels. The achievement is being described in the same terms as breaking the sound barrier, so impressive are its possible implications for solar thermal technology.

So what is it exactly that these Chuck Yaegers of the solar world have gone and done?

Put simply, the temperature of the steam they created (570° C) is about twice the maximum heat of your kitchen oven – or around the point where aluminium alloy would start melting. And the accompanying pressure (23.5 megapascals) is about 100 times as high as the pressure in your car tyres, or roughly what you’d experience if you were about 2 kilometres under the surface of the ocean.

Solar thermal tower.

The solar thermal tower in action: check out the steam being generated.

That’s all impressive in itself. But when you take into consideration that this is the first time solar power has ever been used to create these ‘supercritical’ levels on this scale – traditionally only ever reached using the burning of fossil fuels – the real worth of this achievement begins to sink in.

Solar thermal, or concentrating solar power (CSP) power plants have traditionally only ever operated at ‘subcritical’ levels, meaning they could not match the efficiency or output of the world’s most state of the art fossil fuel power plants.

How a solar thermal power plant works.

How a supercritical solar thermal power plant would work.

Enter our team and their Advanced Solar Steam Receiver Project. To prove that solar thermal technology can match it with the best fossil fuel systems, they developed a fully automated control system which predicts the heat delivered from every mirror (or heliostat), allowing them to achieve maximum heat transfer, without overheating and fatiguing the receiver. With this amount of control, they were able to accurately recreate the temperature and pressures needed for supercritical success.

So instead of relying on burning coal to produce supercritical steam, this method demonstrates that the power plants of the future could be using the zero emission energy of the sun to reach peak efficiency levels – and at a cheaper price.

While the technology may be a fair way off commercial development, this achievement is a big step in paving the way for a low cost, low emission energy future.

 The $5.68 million research program is supported by the Australian Renewable Energy Agency and is part of a broader collaboration with Abengoa Solar, the largest supplier of solar thermal electricity in the world. 

For media inquiries, contact Simon Hunter – Phone: +61 3 9545 8412 Email: simon.hunter<at>csiro.au

33 Comments on “Our solar team sets a hot and steamy world record”

  1. Amanda says:

    This is so very exciting I will deferentially be following this technology developments progress. Congratulations CSIRO

  2. glenn2point0 says:

    Amazing stuff. Scientific research like this should be given greater funding.

  3. Remind me again why the Federal Government is cutting back on Science?

  4. I’m curious if towers like this could concurrently be used for desalination considering they’re boiling water in the process any way? I understand that the salt may have a corrosive effect which would be a deterrent but it seems like the two processes could go easily hand in hand. Are you aware of any research regarding this?

    • Nicholas Kachel says:

      Hi Talia. I’ll pass this over to one of our scientists working on this project, Mike Collins:

      “The water used in steam cycles is very pure and pH controlled to address the corrosion issues that you have mentioned.

      However there are some interesting opportunities for combining CSP with desalination. CSIRO is an active member of SolarPACES, who are coordinating a stream of work in this area: http://www.solarpaces.org/tasks/task-vi-solar-energy-and-water-processes-and-applications/concentrating-solar-power-and-desalination-plants



      • Dear Mr. Kachel,
        I host and produce a public radio program that airs throughout Southern California on Saturday mornings at 10-11am on Pacifica Radio KPFK 90.7 FM. We produce feature length interviews with authors, inventors, scientists and entrepreneurs. Our most famous guests last year would probably be Former President Al Gore and U.S. Astronaut Buzz Aldrin, but we specifically seek out lesser known equally geeky guests including Dr. Leonard Kleinrock, the UCLA professor who ran the lab at UCLA that sent the first message to Stanford on the ARPANET, the predecessor to the internet.
        I read CSIRO’s recent blog post “Our solar team sets a hot and steamy world record” and would like to discuss your achievement of a world record for steam pressure and temperature in your experimental solar thermal power plant.
        Brandon Barney
        Producer and Co-Host
        Digital Village Radio
        Saturdays 10:00-11:00 AM Pacific Time
        KPFK/Pacifica (90.7/93.7/98.7/99.5 FM)
        Los Angeles/San Diego/Santa Barbara/China Lake

  5. Anthony Barnes says:

    Every Government MP needs to see this innovation and get seriously behind efforts to deploy and expand it’s implementation.Our planet can’t wait.I’ve already contacted my MP Alan Tudge.

  6. Anne-Marie Stranger says:

    this really is the most sensible approach and if the desalination was an option it would be wonderful news

  7. Anders says:

    Congratulations on achieving this promising milestone! What are the capabilities for storing the energy produced for distribution during cloudy periods?

  8. Kevin says:

    This is a commendable advance. However, what happens when the sun is not shining? I think it would not be a good idea for this to be linked to the grid, unless you have some sort of storage… Or maybe the resulting electricity can be used for something else than powering the grid?

    • Kevin: Variation is a good reason -to- be connected to the grid! This solution does have -some- storage, in heat. I don’t know how much, but it would be possible to measure the variation and respond before it affects output. Actually, that’s what this article says – individual mirrors are redirected to regulate the energy harvest.. This is a much more manageable solution than wind turbines and domestic PV panels.

  9. Michael Cortie says:

    Very hot steam generated from the sun is a helpful step in the direction of getting a better Carnot efficiency, but the real issue is how many watts of power are generated in this experiment or in some scale-up of it. The press release is silent on this vital issue.

  10. Neat!
    Now add a 2nd receiver (and turbine?), scaled differently to the first. Depending on the conditions or time of day, aim all reflectors at the small tower, the large tower, or both. Maximise benefit from a fixed size reflector array.

  11. proudtobesouthaustralian says:

    Old news! This technique – already used world-wide and not invented by CSIRO – has been welcomed in South Australia to replace the old coal power plant at Port Augusta. Please see: http://repowerportaugusta.org/ and http://media.bze.org.au/Repowering_PortAugusta.pdf .
    But, of course, this is South Australia (where CSIRO first began, incidentally) so it does not make news…

    • Nicholas Kachel says:

      Hi there

      I will hand over again to Mike Collins, one of our scientists working on the project:

      “Yes, older solar thermal power station designs could have powered old turbines like the one used at the Alinta plant in Port Augusta.

      However, the results achieved by the CSIRO team could see not just these “sub-critical” turbines powered by the sun, but even state of the art plants with the world’s most advanced supercritical steam turbines.”

  12. Carl Joseph says:

    Well done champs. Proud of my CSIRO. Pity the government is cutting the funding source for this, the Australian Renewable Energy Agency.

    A question … how much more efficient is this than generating electricity directly through photovoltaic cells?

    Also, is the entire system energy positive and self-contained? e.g. where does the power come from to pump the water up the tower? Does this come from within the steam produced energy itself?

    • Nicholas Kachel says:

      Hi Carl

      Robbie McNaughton, our project lead, has addressed your questions:

      “It is difficult to give a straight comparison between solar thermal and PV as they have unique strengths, weakness, costs and daily/annual capacities. The peak efficiency is only one parameter.

      Yes, the system is energy positive and self contained. The water pump is powered by the system itself and only consumes a small fraction of the net power.”



  13. How much steam was produced??? (Volume: Lbs/hour?)

    My guess is, very little, or else this would be commercially viable now…

    They always seem to leave the pertinent information out when it isn’t positive.

    • Nicholas Kachel says:

      Hi automaticsteam, thanks for your comment. Here’s a response from project lead, Robbie McNaughton:

      “Steam flowed at around 330kg/hr , which equates to a little over 300kW of adsorbed solar energy. The experiments were designed to represent a single element of large scale design, so scale up is related more to multiplicity than redefining heat and mass fluxes.”

      • Thank you Nicholas so much for the response.

        My 1000 sq ft home has 10, 1.5kW/hr electric resistance heaters (baseboard); 15kW/hr total. In moderately freezing temperatures; around 20F / -6.66C, my heat will run about 1/3 of the hour; 20 minutes, or expend 5kW.

        Roughly, 300kW is about enough energy to heat 60 such homes here.

        The project output at 330kg/hr equates to about 666lbs/hr@34.5lbs/hr equalling roughly 20hp – the size of a steam boiler used in a large corner dry cleaning plant.

        I think the project has proven that the technology is abjectly inviable. That in itself is very valuable information. Time to move on.

        No multiplicity of cells, as we understand energy/steam generation today will ever move or improve the economy of scale more than about one iota. The laws of physics say so.

        I think tapping into magma is far more viable, and good fortune has it, right now the Earth’s core is heating up, and magma is coming closer to the surface.

        I would like for the team to help me develop the quantum frostless heat pump (US patent 7,895,850) which we can make commercial within 2 years, and save 10% over current heat pump technology, simply, cheaply, easily.

        Heat pump; geothermal, water to air, and air to air, are the future for now for practical electric heat.

        As to the steam temperatures and pressures the project developed, lauching jets off an aircraft carrier would be a great application, but the required boiler horsepower to launch a jet would be about 50 times greater than the project produced.

        Am I missing something here?

  14. Paul says:

    Can this technology also take in the “salt rock” experiments being done by Gemasolar power plant in Seville, Spain to heat steam for night time use? The radiation heats molten salts that circulate inside the tower to temperatures of more than 500 °C (932 °F). The hot molten salts are then stored in tanks that are specially designed to maintain the high temperatures. This cutting-edge heat storage system enables the power plant to run steam turbines and generate electricity for up to 15 hours without any incoming solar radiation. Obviously incorporating both systems into one technology would be awsome and I believe really assist this great new breaking technology that you have created.

    Read more at: http://phys.org/news/2011-07-gemasolar-solar-thermal-power-hours.html#nRlv

  15. How about this combination of technology making use of technically simpler challenge than super-critical steam. (… The reason is that a substantial number of coal-fired plants are planned for construction and a financially superior technology is the most irrefutable argument against these projects commencing.)

    1. GreatPoint Energy has a catalytic methanation process that users steam to convert carbon-rich feedstocks – such as coal, petcoke, and biomass into a methane-rich gas stream from which CO2 is readily separated.

    2. Algae.Tec has a process for growing algae from concentrated sunlight and CO2. The algae is most profitable in nutrient supplements, but can also produce edible oil to replace palm oil. Algae may also be used for stock feed.

    The production of methane from coal allows electricity to be generated in combined heat and power distributed units and in CCGT power plants with efficiencies over 60 percent. This is far better than the most advanced supercritical coal-fired plant which can only achieve about 45 percent efficiency.

    The embedding of solar thermal energy in the methane produced from coal or biomass with GreatPoint Energy’s technology avoids the cost of thermal energy storage.

    Combining CSIRO’s solar thermal technology with these other two proven technologies – GreatPoint Energy and Algae.Tec’s – provides a faster and technically simpler path to commercial realisation and avoiding construction of more coal-fired plants.

  16. This is amazing technology. I am very interested in the design of the collectors, concentrators and turbine to share with my students. I would like to make a miniaturized version for a class project here in New Haven, CT. Can you tell me what kind of turbines are being used? The nature of design materials, etc?
    Thank you for your efforts on trying to save our skin. I am sorry our governments are so shortsighted…

  17. louisecusack says:

    Wow, what an awesome achievement! Well done and big pats on the back all around. Just wonder if you can tweak your press releases. Instead of saying “zero emission energy” can you say “zero pollution” so people who aren’t technically minded don’t get lost in the jargon and fail to realize the huge importance this could make in minimizing global warming.

  18. Paul Newon says:

    wow! it keeps getting better all the time, keep up CSIRO…

  19. Ursitoare says:

    Amazing solar setup, but what was the peak temperature that they recorded if it’s a new world record ?

  20. brent says:

    My oven goes up to about 520 Kelvin. 540C = 813. That’s not twice. It’s about 1.5 times.

  21. shiva says:

    Its an awesome technology and congratulation to CSIRO

  22. Bill says:

    I’m sorry, but this is a reality check.
    Inasmuch as this technology is desireable, it is not economically viable.
    All that apparatus produces about 20 horsepower.
    Do the math.

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