Agreed concentration

Image source: CSIRO
29 November 2016

CSIRO's heliostat technology will be rolled out in China as part of the country's uptake of solar thermal (CST) for electricity generation.

CSIRO has signed an agreement with Chinese company Thermal Focus, which will market, sell and install the low cost heliostats in China. CSIRO's share of the revenue will be used to fund climate mitigation research in Australia.

China aims to produce 1.4 gigawatt (GW) of CST by 2018, and up to 5 GW by 2020. This would double the capacity of the world's currently installed CST plants.

CST technologies are based on reflectors that collect solar radiation and concentrate it on a receiver with a much smaller area, where it is used to heat a transfer fluid that stores the thermal energy. The stored energy can then generate superheated steam to drive a turbine for electricity generation,

CSIRO's technology uses a field of computer-controlled mirrors or heliostats that accurately reflect and concentrate sunlight onto a receiver on top of a tower, where the thermal energy is stored by heating molten salt to temperatures of around 560°.

According to CSIRO, an advantage of the system is the very low cost of storing thermal energy, giving CST technology great potential for medium to large-scale solar power, even when the sun isn’t shining.

The Heliostat field can account for up to 40% of the total plant cost.

CSIRO’s software optimises the configuration of the heliostats prior to construction and manages each heliostat to ensure the optimum amount of reflected heat is focused on the receiver, maximising the amount of power that can be produced.

Its research base for the technology is the CSIRO Energy Centre in Newcastle, where CSIRO researchers set a world record for the use of solar energy to generate hot and pressurised 'supercritical' steam (23.5 megapascals pressure and up to 570° temperature).

CSIRO's technology is also part of the $86 million Australian Solar Thermal Research Initiative, a CSIRO led global collaboration including six Australian universities that aims to lower the cost of CST technology.