Some early green hydrogen projects in Latin America and Africa could already produce hydrogen for as little as $2-3/ kg, according to a report from certification body DNV.

The firm foresees a role for all four main technologies—alkaline electrolysis, proton exchange membrane (PEM), solid oxide electrolysis (SOE), and anion exchange membrane (AEM).

While AE and PEM are competing for commercial position, SOE has just entered the market via three manufacturers. SOE development mainly focuses on improving the stability and lifetime of the stack, increasing capacity and reducing costs.

“We might also see electrolysis offshore on (artificial) islands, platforms, or even integrated into wind turbines” DNV

SOE will likely be applied in combination with a stable power supply, integrated with other processes in ammonia and synthetic fuel production, and possibly in reverse operation to convert hydrogen back into electricity.

“Costs are predicted to decrease by 50pc solely on the basis of economies of scale,” says the report, titled DNV Technology Progress Report 2021. “This should enable SOE to compete with AE and PEM by 2030.”

The report notes that AEM still requires the most development, with systems at the moment too small to be commercially viable. But it adds that successful development of AEM could allow the technology to join AE and PEM in applications across many sectors.

Some firms say the technology has the opportunity to lower the cost of green hydrogen production because of cheaper components. The various different technologies will be needed because of the wide range of applications that electrolysers will be deployed in, according to the report.

Electrolysis plants could be built onshore either as large centralised plants towards gigawatt-scale, or small and decentralised plants to supply local demand, in mobility for example, it says. “We might also see electrolysis offshore on (artificial) islands, platforms, or even integrated into wind turbines.”

Large wind farm operators are assessing the possibilities of integrating hydrogen with offshore wind, it notes, requiring systems to be compact, reliable and suitable for remote operation.

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Author: Tom Young