A new electrolysis system can pump green hydrogen from water without an expensive membrane, taking a giant step toward the $1-per-kg goal.

Membrane-Free Green Hydrogen To Chase The Fossil Fuel Blues Away

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Fossil fuel stakeholders are depending on petrochemicals to stay afloat as renewable energy takes over the power generation sector, but new green hydrogen technology is beginning to pull the rug out from under their feet. For now, the relatively high cost of green hydrogen is shielding fossil energy from competition. Nevertheless, costs are dropping, and a new membrane-free electrolysis system could force a day of reckoning upon coal, oil, and natural gas sooner rather than later.

Chasing The Green Hydrogen Unicorn

CleanTechnica first encountered the green hydrogen topic in 2015, when we embarked on a technology tour of Switzerland that took us to EPFL, the École Polytechnique Fédérale de Lausanne.

The perovskite solar cell research of Professor Michael Graetzel, head of the school’s Laboratory of Photonics and Interfaces, was the main purpose of the visit. We were also invited to a hydrogen presentation by Professor Kevin Sivula, head of the Molecular Engineering of Optoelectronic Nanomaterials Lab.

“EPFL is one of a number of A-list research institutions turning attention to solar-powered hydrogen production, aka a ‘solar refinery’ that can churn out hydrogen — essentially, a means of storing solar energy in a simple chemical bond,” we reported.

“The idea, as Sivula describes it, is that solar hydrogen would provide a stable solar energy storage platform for plastics manufacturing and the many other economic sectors that currently rely on fossil sources for foundational ingredients, in addition to enabling solar-based fuel for aircraft as well as ground vehicles,” we added.

The idea seemed rather mysterious back then but the basic technology was already well in hand, in the form of electrolysis systems that deploy an electrical current and a catalyst to push hydrogen gas from water.

That, in a nutshell, is green hydrogen. And the problem, in a nutshell, is cost.

Sivula told CleanTechnica that green hydrogen would cost about $10.00 USD per kilogram, based partly on using conventional silicon solar cells to supply the electricity.

Bringing Down The Cost Of Green Hydrogen

The cost of solar power has dropped considerably in the nine years since 2015, helping to push the cost of electrolysis down. Green hydrogen stakeholders can also take advantage of low-cost wind power and other renewables. Improvements in electrolyzer technology and scaleup in the electrolyzer manufacturing industry are also lending an assist.

Still, progress has been slow. The US Department of Energy uses a ballpark figure of $5.00 per kilogram for green hydrogen sourced with electrolysis systems today, which is a long way from the goal of $1.00 per kilogram by 2030.

In contrast, the International Energy Agency puts the cost of fossil-sourced hydrogen in the range of 50 cents to $1.70 for fossil-sourced hydrogen, depending on the region. With the addition of carbon capture systems the cost goes up, but IEA still puts it well below the cost of green hydrogen, at $1.00 to $2.00 per kilogram.

Look Ma, No Membrane

One sticking point is the stubbornly high cost of the membrane, which is an essential part of an electrolyzer system.

Or, maybe the membrane is not so essential after all. Membrane-free electrolysis is beginning to happen, one example being a new system developed by the Israeli startup H2Pro. The company came across the CleanTechnica radar in 2022, when we were reading up on the $100 million “XCarb Accelerator Programme” under the wing of the leading steel maker ArcelorMittal.

“ArcelorMittal points out that the XCarb Innovation Fund launched in March 2021 and it already has $180 million in the pipeline, consisting of four companies that have sailed across the CleanTechnica radar in recent years,” we wrote. H2Pro’s membrane-free electrolysis system made the cut along with Heliogen’s concentrating solar power solution, Form Energy’s long duration energy storage system, and LanzaTech’s industrial waste gas upcycling system.

ArcelorMittal was not the only one to notice. H2Pro spun out of Technion (the Israel Institute of Technology) in 2019. The very next year it caught the eye of the US company New Fortress Energy, which tasked its Zero hydrogen division to work with H2Pro on demonstration projects, with the goal of demonstrating the feasibility of $1.00 per kilogram for green hydrogen.

The Long (Or Short) Road To $1.00 Per Kilogram Green Hydrogen

Things have moved along at a rapid clip since then. In 2021 H2Pro hooked up with the Israeli renewable energy firm Doral Energy, which is no small potatoes. Doral describes itself as a “global renewable energy developer, with 15 GW of renewable assets under development.” The agreement with H2Pro is part of Doral’s plan to establish a “large green hydrogen project pipeline worldwide.”

In 2022, the Bill Gates firm Breakthrough Energy Ventures put up a $22 million stake in H2Pro’s membrane-free electrolysis system.(see more Breakthrough coverage here).

And, now we come to the part that will probably give fossil energy stakeholders a headache. Hydrogen is the petrochemical workhorse of the modern industrial society, used to produce ammonia fertilizer as well as pharmaceuticals and other products. It is also used in systems like steel making, which explains AcelorMitall’s interest.

Currently, the primary source of the global hydrogen supply is natural gas, with coal chipping in some as well, which means that natural gas and coal are essential for ammonia production — but apparently, not for much longer.

Last spring H2Pro and the sprawling Japanese Fortune 500 conglomerate Sumitomo Corporation announced an agreement to deploy H2Pro’s membrane-free electrolyzers, primarily to produce hydrogen for green ammonia projects. Somewhere  along the way Sumitomo also became an investor in the company.

“The agreement between H2Pro and its investor-turned-partner is a critical strategic move for H2Pro to scale its technology,” the partners noted in a joint press release on March 8, 2023.

The agreement calls for Sumitomo and its partners to work with H2Pro on pilot and demonstration projects, including an assist with manufacturing equipment. “By the second half of this decade, Sumitomo plans to incorporate H2Pro’s electrolyzer technology, both within and outside the Sumitomo Corporation Group, toward the production of several hundred tons of green hydrogen per day,” the partners stated.


Wait, How Does It Work?

As for how exactly this works, in November last year the news organization C&N tapped H2Pro for a spot in its 2023 “10 Startups to Watch” list.

Writing for C&N, reporter Alex Scott explained that conventional electrolyzers are only about 70% efficient in terms of converting electricity to chemical energy, while H2Pro’s E-TAC (short for electrochemical thermally activated chemical) system achieves 95% conversion efficiency.

As described by Scott, E-TAC deploys a two-step process that avoids mixing hydrogen and oxygen, which is why the system does not require a membrane. That’s the key to reducing the cost of building the system, which is reportedly 50% less than a conventional electrolyzer. The second step of the process is also an energy efficient money-saver, contributing to a significant savings on operating costs.

For the latest word on membrane-free green hydrogen check out the study, “Electrochemical and chemical cycle for high-efficiency decoupled water splitting in a near-neutral electrolyte.” Published in the journal Nature Materials on January 9, the study was conducted by a Technion team headed up by Professor Avner Rothschild of the Department of Materials Science and Engineering, who co-founded H2Pro with other Technion scientists Dr. Hen Dotan and Professor Gideon Grader.

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Image: A new membrane-free electrolyzer system produces green hydrogen from water (screenshot, courtesy of H2Pro).

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Tina Casey

Tina specializes in advanced energy technology, military sustainability, emerging materials, biofuels, ESG and related policy and political matters. Views expressed are her own. Follow her on LinkedIn, Threads, or Bluesky.

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