CSIRO demonstrates new “beam-down” solar reactor to accelerate green hydrogen production

Australia’s premier science agency CSIRO says it has successfully demonstrated a new way to produce green hydrogen using a combination of concentrated solar power (CSP) and modified metal oxide.

Backed by funding from the Australian Renewable Energy Agency (ARENA), the so-called “beam-down” solar reactor was developed at CSIRO’s Newcastle Energy Centre.

Unlike traditional CSP technology, which concentrates sunlight onto the top of a tower, the new design directs it down onto a platform, a little like using a magnifying glass to focus sunlight.

The technology redirects the sunlight downward into a separate solar reactor located on a lower platform, where the concentrated heat is used to power electrolysis – a chemical reaction that splits water into its component atoms, hydrogen and oxygen.

The key to CSIRO’s beam-down design – the first time this technology has been demonstrated in Australia – is located in the solar reactor, where the use of a modified metal oxide improves the ability to absorb and release oxygen at a much lower temperature, the oxygen exchange core to the production of green hydrogen.  

According to CSIRO, the modified metal oxide – called doped ceria and developed by researchers at Niigata University in Japan – releases some oxygen atoms when heated by solar energy.

But, when exposed to steam, it absorbs oxygen from water – leaving hydrogen gas to be captured and stored for later use as a fuel or in industrial processes.

The doped ceria is then ready to be repeatedly reused.

The use of doped ceria at CSIRO’s Newcastle Energy Centre is the first time the modified metal oxides have been used in a demonstration-scale test, and according to Professor Tatsuya Kodama from Niigata University, the particles have excellent performance as the catalyst.

“We can produce over three times more hydrogen than what’s typically achieved using standard materials in a similar reaction,” said Kodama.

“That shows real promise for improving the efficiency in future designs.

“We also gained valuable insights into how we can further develop the particles to improve the overall process.”

The development of this new beam-down technology could serve as an important breakthrough in the decarbonisation of Australia’s industrial processes. Specifically, according to CSIRO, around 75 per cent of Australia’s national energy use comes from fuel-based sources – particularly in heavy industry and transport.

Reliance on these emissions intensive fuel-based sources has been hard to overcome, with electrification technologies often unable to deliver the same performance.

However, CSIRO computer scientist and solar thermal researcher Michael Rae expects green hydrogen to play an important role in Australia’s transition to net zero – a role which will be bolstered by CSIRO’s new beam-down technology.

“Most hydrogen today is made from methane, a process that releases emissions, known as grey hydrogen,” Rae said.

“To make green hydrogen, we need methods that can produce it in large volumes, reliably and cost-effectively, without relying on fossil fuels.”