It’s no secret. If green hydrogen wants to play a decisive role in the future and contribute to the decarbonisation of the economy, especially in heavy industry and long-distance transport, two sectors in which electrification can be more complex, it must first face a key challenge: lower costs. The challenge is not easy. Nor minor. Its high bill, with a price that is eight times that of natural gas, is already leading some companies to postpone the leap towards clean energy and postponing the goodbye to fossil fuel.
Hence, there are those who are looking for ways to reduce their bill… even making the devices used to generate it cheaper.
Important… And expensive? Green, blue, grey, pink… Hydrogen as such is colourless, but depending on how we obtain it and the environmental footprint of the process, we assign it one or another chromatic “surname”. Brown, for example, is obtained through the gasification of coal, which explains why CO2 is released during its production. Pink, defended tooth and nail by France, takes advantage of the energy of nuclear power plants.
In this extensive chromatic arc, green identifies that hydrogen that we obtain from the electrolysis of water and the use of energy generated from renewable sources, such as wind or photovoltaic. Some are convinced that it is a key ally to decarbonise sectors in which electrification may be more difficult, such as heavy industry or long-haul transport, and the truth is that the sector has taken steps in that direction. The problem: Green hydrogen may be clean, but it’s also expensive. Very expensive.
How expensive? The European Energy Exchange (EEX) recently launched a tool that helps us answer that question: Hydrix, a market-based hydrogen index that is regularly updated with prices calculated based on supply and demand. Its latest available data corresponds to the second week of June and places the value at €259.83/MWh, slightly above the values of the previous five weeks, when the estimates ranged more or less between €217 and €231/MWh .
To understand the data, it is worth taking a look at the Title Transfer Facility (TTF), a reference for the price of natural gas in Europe. Its latest data places its price below 30 euros. The values are not immutable, of course, and the escalation experienced by gas barely a year ago is still recent, when the TTF climbed to €340/MWh due to the influence of the war in Ukraine, but the truth is that today green hydrogen is considerably more expensive than the fossil alternative. And that has already led some companies to warn that they will not make the leap to the renewable option until it is “commercially competitive”.
And how to reduce costs? That is the question that has been asked at the Korea Institute of Science and Technology (KIST), where they have decided to bet on a peculiar strategy: lower the bill for hydrogen production… while lowering the cost of the tools used during electrolysis. , which is the phase in which electric current is used to decompose —with electrodes— the water molecule into oxygen and hydrogen.
To achieve this, they have decided to reduce the amount of rare metals they incorporate. “Due to the high cost of producing water electrolysis devices, the economic viability of green hydrogen has not been very high,” explains KIST. “However, the development of a technology that drastically reduces the amount of rare metals such as iridium and platinum used in devices with polymer electrolyte membranes is leading the way in reducing production costs.” Both metals are on the list of critical minerals drawn up last year by the International Energy Agency, the IEA.
How have they achieved it? What Hyun S. Park, Sung Jong Yoo and the rest of their KIST colleagues have done is develop technology that “significantly reduces” the amount of platinum and iridium typically used in devices used for electrolysis. The merit of their proposal is that they have achieved this saving – they guarantee from the Korean center – with a level of performance and durability similar to those offered by conventional equipment.
“The researchers replaced the precious metal in the electrode’s protective layer with low-cost iron nitride that has a large surface area, and evenly coated a small amount of iridium catalyst on top, increasing the economic efficiency of the device.” Ditch the KIST, which recalls that electrolysis devices usually incorporate gold, platinum or iridium, metals with very low reserves and production volumes. “It’s a factor that makes the adoption of hydrogen production devices difficult.”
And beyond the laboratory? Park explains that they will continue to study the performance and durability of the electrode, but they want to go further and transfer it to commercial devices “in the near future.” “Reducing the amount of iridium catalyst and developing alternative materials for the platinum protective layer are essential for the widespread and economical use of green polymer electrolyte membrane hydrogen production devices,” the professor highlights. For him the key is in the iron nitride.
Are they the only ones working on that line? No. At the Argonne National Laboratory, of the United States Department of Energy, they have just presented a low-cost catalyst to obtain clean hydrogen from water. Their objective is the same: to reduce costs. And to achieve this they have adopted an approach very similar to that of Park and Yoo: lighten the bill for the materials used. “One problem is that the anode catalyst uses iridium, which currently has a market price of around $5,000 an ounce. Its lack of supply and cost is an obstacle.”
For this reason, they propose a new catalyst that incorporates cobalt as the “main ingredient”, which is cheaper than iridium. “Using the cobalt-based catalyst prepared by our method could remove the main cost bottleneck for producing clean hydrogen in an electrolyser,” says Di-Jia Liu, an Argonne chemist and Pritzker School researcher.
Top image: Argonne National Laboratory
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