RenewEconomy Article : Fortescue-backed sunlight-to-hydrogen pilot goes live

“Untamed dream”: Fortescue-backed sunlight-to-hydrogen pilot goes live

A groundbreaking sunlight-to-hydrogen pilot plant launched in Adelaide today just three months after construction started, with a goal to dramatically improve the economics of making the green gas.The green hydrogen reactor is the first real-world test of University of Adelaide professor Greg Metha’s photocatalytic water splitting technology, a process which ditches electrolysers in favour of pure sunlight to separate hydrogen from water molecules. The reactor is a big step towards finding a way to commercialise the technology, says Nick O’Loughlin, the managing director of the company spearheading the project, Sparc Technologies.“In an environment where major challenges exist for hydrogen projects due to the high cost of power, the requirement for new solutions to unlock low-cost green hydrogen without relying on electrolysers has never been higher,” he said. The company declined to say what the facility’s production capacity might be, but did say the plant will test different photocatalysts and reactor configurations after it’s commissioned in July.The project is owned by a joint venture of ASX-listed Sparc Technologies, billionaire Andrew Forrest’s Fortescue and the University of Adelaide, and is the result of years of work. Holy grail: dumping electrolysers

Fortescue chair Andrew Forrest earlier this year hinted at a potential breakthrough in hydrogen technology, although he declined to provide specifics.“There is a new form of hydrogen, which will come onto the marketplace, which will be a lot cheaper,” he told Bloomberg in an interview. “We’re not yet in a position where I want to talk about it publicly.”Fortescue declined on Tuesday to say if this technology is the one, but it has been seen by the industry as something of a holy grail.In 2022, a desktop analysis suggested that if the photocatalyst and reactor met assumed benchmarks, then the benefits outweighed the risk of the trio investing more money into the idea. That was enough to prompt the joint venture partners to start doing the work required to build a reactor. The ultimate goal is to commercialise a green hydrogen technology that can avoid electrolysers and the likely-unrealistic volumes of wind and solar power required to deliver significant production. “This next-generation photocatalytic water splitting technology has major advantages over electrolysis as it offers the potential to produce low cost, scalable green hydrogen and heat without significant electricity use,” Metha said in a statement. “The SHARP plant at the University of Adelaide’s Roseworthy campus will allow us to independently and concurrently test different reactor designs and photocatalyst materials.”For Fortescue, the plant is another element of its attempts to be a player in green hydrogen as it refocuses on R&D over production. Last year the company put on hold its ambitious goal to produce 15 million tonnes of renewable hydrogen annually by 2030, and in March cut 90 hydrogen jobs including at its Gladstone PEM50 electrolyser project in Queensland.The company cited global headwinds and a return to R&D, rather than manufacturing.Inspired by nature and really, really difficultPhotocatalytic water splitting is inspired by photosynthesis in nature, and was discovered in the 1960s by Japanese researchers.It uses a chemical process that uses sunlight, concentrated by mirrors or lens into an intense beam, and a photocatalyst to break apart water molecules into hydrogen and oxygen. The photocatalyst absorbs photons from light which ‘excites’ electrons. The energised electrons leave holes on the molecule where they had been positioned, and this is destabilising enough to break it into its parts. It’s an idea that over the last 15 years researchers have labelled a “holy grail” of clean energy and “the untamed dream”.The Adelaide pilot aims to improve the economics of producing green hydrogen using this technology with a photocatalyst supplied by Japan’s Shinshu University.A swathe of academic papers outlines just how difficult the joint venture’s ambition is.In 2021, a paper in the Chemical Engineering Journal noted that despite new reactors and photocatalysts, and other advances, the process was still only yielding a solar-to-hydrogen efficiency of less than 1 per cent.To be economically viable, that figure needs to come up to 10 per cent. The target for the Adelaide reactor is 5 per cent.The paper also pointed out that the electron likes to recombine with its vacant hole before the splitting action happens, which is another factor driving low efficiency. Last year, a team of researchers from Japan, the UK and China outlined just how big a challenge the Adelaide project has ahead of it in turning a lab idea into a commercially viable process. “An elaborate laboratory-scale photovoltaic-powered electrolyzer can exhibit an STH [solar to hydrogen] efficiency of 30 per cent and pilot-scale plants based on this technology have been constructed worldwide. Even so, large-scale production of solar hydrogen is likely still more expensive than generating hydrogen from fossil resources,” the researchers wrote in the Frontiers in Science journal. “Advances that enable the deployment of water-splitting photocatalysts over large areas are necessary, as is the ability to recover hydrogen safely and efficiently from the produced oxyhydrogen gas.”Key design issues include the cost of materials needed to concentrate sunlight, and controlling conditions within the plant to keep the reaction on track and reduce the potential for unwanted side-reactions.