Paving the Way for Affordable and Efficient Concentrated Solar Thermal Technology

The National Science Agency of Australia (CSIRO) has made a technological breakthrough in the use of concentrated solar thermal technology (CST).

CST uses large mirrors or lenses to focus sunlight onto a narrow region known as the receiver.  The mirrors – AKA, solar collectors – have distinct designs and focusing techniques, and can include dish systems, solar power towers, and parabolic troughs. The receivers contain heat-transfer fluids, such as molten salt or high-temperature oil. Previously, the efficient use of CST has been hindered as it requires a favorable climate with constant sunshine in order to function at its best, and it is expensive. 

The team at CSIRO were able to reach a crucial milestone temperature of 803 °C at the receiver for the first time ever. Conventional CST practices use heat transfer fluids that can only endure 400°C to 600°C. The researchers instead used ceramic particles that can tolerate temperatures of over 1000°C in order to optimize and simplify the system. 

“This is significant because it creates the opportunity for greater renewable energy storage when combined with our patented heat exchanger,” said Dr Jin-Soo Kim, the team lead. “This technology is key to delivering low-cost renewable energy at scale for the decarbonization of Australia’s heavy industry. Over eight years of development and thousands of hours were invested to reach this outcome.”

The team expects that this innovation will provide a strong alternative to traditional PV solar energy.

“CST doesn’t compete with PV solar energy,” said Dominic Zaal, Director of the Australian Solar Thermal Research Institute. “PV gives you power when the sun is shining, whereas CST takes energy from the sun, stores it and then allows the user to use that energy when the sun isn’t shining, such as overnight or on cloudy days.”