Concentrated Solar Thermal (CST) uses mirrors to concentrate sunlight, converting it to heat, which can then be stored or used to generate electricity.

Heated ceramic particles act like a battery, storing energy as heat, for up to 15 hours. As the particles cool, they release this energy. They could provide power whenever it's needed, even at night and during periods of low solar and wind output.

Traditional CSTs are limited by the heat transfer fluids they use. Common fluids, like molten salt or high-temperature oil, can only handle up to 600°C and 400°C, respectively.

However, the ceramic particles the team is working with can endure temperatures over 1000°C. These particles not only absorb the sun's heat but also store it, simplifying the system and reducing costs.

The 'falling' part of this method uses gravity to heat these tiny, dark-hued ceramic particles. Each particle is less than half a millimetre in size. The particles are dropped from a hopper at the top of the tower, and heated as they pass through focused solar energy. In a shortfall, their temperature can shoot from 500°C to 800°C, and with more advanced setups, possibly over 1000°C.

Unlike traditional methods that rely on steel tubes, the particles fall freely. This approach avoids the heat limitations of steel. Once heated, they're stored in a silo. When needed, they're used to produce steam for power generation or other industrial tasks.

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.

CSIRO's pilot system in Newcastle has 400 mirrors. However, a full-scale one might use over 10,000 larger mirrors. These can generate power similar to a 100 MW coal plant.