Breakthrough in Solar Power Technology Could Replace Fossil Fuels in Heavy Manufacturing

The world of manufacturing is on the cusp of a revolution, as a potentially groundbreaking solar-powered device has achieved temperatures over 1,000°C, raising hopes for using green energy to run some of the most fossil fuel-intensive manufacturing processes on Earth.

Harnessing the power of the sun

The new proof-of-concept technology uses synthetic quartz crystals to trap solar energy at temperatures over 1,000°C, demonstrating its potential to provide clean energy for carbon-intensive industries like metal, cement, and chemicals manufacturing.

“Previous research has only managed to demonstrate the thermal trap effect up to 170°C. Our research showed that solar thermal trapping works not just at low temperatures, but well above 1,000°C.” - Emiliano Casati, ETH Zurich

Making materials like glass, steel, and ceramics needs temperatures over 1,000°C, something that is currently typically only achieved by burning fossil fuels. These manufacturing industries account for nearly a quarter of the world’s energy consumption.

The new device, built by attaching synthetic quartz crystals to an opaque silicon disk, makes use of a phenomenon called the thermal trap effect to harness sunlight at previously unseen levels of efficiency.

The secret to harnessing solar energy

The working principle is that opaque materials exposed to solar radiation absorb it at the surface and transfer it inside by conduction, while semi-transparent materials let sunlight penetrate and undergo absorption across the inner volume. By properly matching semi-transparent materials with an appropriate energy radiation source, it is possible to achieve temperatures that are higher in the bulk of the material than at the surface exposed to solar radiation – in other words, creating a thermal trap.

When researchers exposed their device to an energy flux equivalent to light coming from 136 suns, one end of the devices reached 1,050°C and the other 600°C.

The researchers are currently optimising the thermal trap effect and investigating new applications for the method. Preliminary analysis exploring other materials revealed that even higher temperatures could be reached.

“This study contributes to the development of more efficient solar receivers to decarbonise key industrial processes requiring high heat, such as the manufacturing of cement and metals and the thermochemical production of solar fuels.” - Dr Casati

The potential implications of this technology are enormous, and could pave the way for a cleaner, more sustainable future for manufacturing.

A brighter future for manufacturing