Technology

Australia's Federal Government recently announced close to AU$12 million in funding for concentrated solar power projects, funded through the Australian Solar Institute’s Round 3 grants program.

By Giles Parkinson in New South Wales, Australia

The third round of funding under the Australia Solar Institute's $150 million research support program has identified four key projects that will look at concentrating solar technologies, along with hybrid and storage solutions. The third round allocated $12 million to 10 projects, leveraging $33 million of total funds.

ASI Investment Director Olivia Coldrey said the Institute is supporting industry to develop solar technologies through new strategic investment into a diverse range of solar technologies, particularly concentrating solar power technologies. One such technology exploits the potential for CSP as an emissions abatement option.

If carbon capture and storage is to be the saviour of the coal-fired generation industry in a low carbon world, there is a major hurdle to overcome – the cost of diverting at least one quarter of a plant’s capacity to providing the energy needed to capture the emissions.

Thermal storage

In post combustion capture technologies that will likely form the principal mechanism for coal plant retrofits, an enormous amount of heat is needed in the carbon capture process, and that heat will no longer be available for power generation - so much so that a 600MW coal plant will be derated to around 450MW.

But what if heat produced from solar thermal technology could be used in its place, and allow the coal-fired power stations to maintain their nameplate capacity? It’s an intriguing idea, and because the CO2 is stored rather than the solar heat – it is effectively a novel storage solution too, and one that is being pursued in a new project by the Australian Solar Institute and Australia’s CSIRO.

James McGregor, the energy systems manager for CSIRO, says his team is looking to use solar thermal as a substitute for the steam that a power station would normally have to produce itself.

The biggest advantage is that this allows the coal fired power station to maintain output, and because solar thermal can deliver a range of temperatures, more options are available for the carbon capture process.

The CSIRO is to test a re-boiler at one of its carbon capture pilot plants at the Vales Point power station, owned by Delta Electricity in NSW. McGregor says parabolic trough technology is most likely to be used in the pilot, but other solar thermal technologies are likely to be suitable.

“The first part of this project  is to demonstrate the potential and assess the economics,” McGregor said. “The follow up projects will be about exploring the different temperature limitations and opportunities presented by using solar thermal systems.”

McGregor said storing the CO2 in the liquid absorbents would provide greater flexibility in operation than thermal energy storage and potentially cost less. The CO2 in the liquid absorbents is stored until the solar thermal energy is available to use during the day time for regeneration.

McGregor said if successful, the technology would not just help coal-fired power stations, but also offer the opportunity for more widespread deployment for solar thermal, enabling it to gain economies of scale through deployment.

Tenders for the solar trough technology providers – likely to amount to around 100kWth, will be sought at the end of the year.

Breaking the heat barrier

Elsewhere, Austalian innovators are working hard to increase the efficiency of CSP while driving down costs. A separate project that the ASI is backing is that of Australian CST developer Vast Solar. The company is investigating a new approach for high temperature receivers and thermal storage systems as it seeks to bring the levelised cost of electricity from solar thermal technology to below $100/MWh.

Vast Solar, an Australian company, has been prototyping and testing solar thermal technology since 2009. The company will work with the University of NSW and Victoria’s RMIT, in a new project, to be partially funded by the Australian Solar Institute.

The project will allow Vast Solar to test high temperature materials and operating processes by expanding its current solar tower facility near the western NSW town of Forbes, with around 500 heliostats. These will take the nominal capacity of the power tower array to around 1.2MWth.

UNSW and RMIT will be focusing on design and testing of a new high temperature receiver, with the project aiming to assess design, materials and performance improvements than can be delivered at temperatures greater than 560C. The project will also refine Vast Solar’s integrated thermal storage system – of which it is saying little at the moment.

Vast Solar was established with private funding from a range of sources including Twynam Agricultural Group, which owns the land where the facility is located. The ASI project is its first government grant.

CEO Andrew Want, who is also head of the Australian Solar Thermal Energy Association, says the company is determined to try and bring the LCOE down to the cost of wind, where its ability to store energy will give it significant advantages.

Is $100/MWh achievable? Want says his team is increasingly confident it is. “A couple of years ago that would been thought to be an outlandish claim. But it is becoming much clearer that solar thermal and central receiver technology can get there quite quickly.”

Its heat transfer technology is also a key focus, but Vast Solar is not talking publicly about the materials it is using, although it does say it is like systems being used in other facilities using molten salts. 

“We are using a different approach,” Want says, “and that does bring specific advantages. It’s not the solution being used around the world at the moment.”

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Rikki Stancich: rstancich@csptoday.com