An Australian Breakthrough Uses Mirrors for Solar Power

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Using solar collectors, concentrated solar thermal technology (CST) harnesses solar energy to produce heat or electricity in a process that is simple yet difficult to execute successfully. It is very expensive and requires a favorable climate with constant sunshine in order to function optimally.

According to Interesting Engineering, large mirrors or lenses focus sunlight onto a narrow region known as the receiver. These mirrors are known as solar collectors and come in various formats with distinct designs and focusing techniques, like dish systems, solar power towers, and parabolic troughs. Then the technology uses a receiver (which is made of heat-transfer fluids such as molten salt or high-temperature oil) situated at the solar collector’s focal point that is in charge of absorbing and turning the concentrated sunlight into heat.

Australia’s National Science Agency CSIRO has recently made a key breakthrough in the technology that could make it very possible and viable both for the nation and the world. The researchers were reportedly able to reach the crucial milestone temperature of 803 °C at the receiver for the first time.

Dr Jin-Soo Kim, who leads the agency’s solar technologies team, called the development significant “because it creates the opportunity for greater renewable energy storage when combined with our patented heat exchanger.”

“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,” he added.

This development uses ceramic particles that can tolerate temperatures of over 1000°C to optimize CST, which simplifies the system and cuts energy costs by both absorbing and storing solar heat. This innovation could offer Australia a strong alternative to the current, limited PV solar energy.

Director of the Australian Solar Thermal Research Institute Dominic Zaal claims that “CST doesn’t compete with PV solar energy”, and explains that PV provides 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.”

The current CSIRO trial system in Newcastle consists of 400 mirrors, while a full-scale one would require over 10,000 larger mirrors, allowing the installation to produce electricity on par with a 100 MW coal plant.