A US start-up says it has developed an entirely new type of electrolyser that is more efficient — and will therefore produce cheaper green hydrogen — than comparative technologies, its CEO tells Recharge.

Chad Mason, the founder of Wisconsin-based Advanced Ionics — which emerges from stealth mode today — explains that the Symbiotic electrolyser requires 35kWh of electricity to produce one kilogram of hydrogen, 30% less than top-range alkaline or PEM machines, which operate at around 50kWh/kgH2.

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The Advanced Ionics electrolyser, however, does require process or waste heat at temperatures above 150°C to reach that efficiency and is therefore only targeting industrial settings.

Solid-oxide electrolysers (SOEs) are also designed to use industrial heat to reduce the amount of electricity required, but those machines need far higher temperatures to operate. For example, SOEs produced by German manufacturer Sunfire require at least 850°C, while Denmark’s Haldor Topsøe needs 700°C for its machines.

Advanced Ionics’ electrolyser can run at any temperature above 150°C, which Mason says is significant because most industrial processes run at 200-600°C.

“Many solid-oxide electrolyser manufacturers don’t count the energy required to 'step up' steam from typical industrial steam to the 800°C required for solid oxide — it's a hidden energy cost,” he states. “Our temperature flexibility allows us to work with whatever is already onsite, often without a step up.”

According to a 2018 study by Italian academics in the journal Applied Thermal Engineering, which looked at the potential for utilising unwanted industrial heat around the world, “not much waste heat is available” in the 500-1,000C range, “with the potential being restricted in the cement, iron and steel sectors”.

“Within the 200–500°C range the potential increases, mainly in pulp and paper and iron and steel industries,” it explains, adding: “The majority of waste heat lies in the temperature range of 100-200°C, spread over most industrial sectors.”

Mason says that his company’s electrolyser will also be cheaper and longer-lasting than solid-oxide machines because Advanced Ionics uses predominantly “stainless steel and a variety of other low-cost materials”, compared to SOEs, which require “delicate, brittle ceramics”.

The symbiotic electrolyser — so-called because it requires heat, electricity and water working in unison — also does not require expensive materials such as the platinum group metals used in PEM (proton-exchange membrane) machines.

“We know what the raw materials costs are in bulk, so we’ll be very, very competitive from a capex [capital expenditure] point of view with alkaline [electrolysers], which also uses pretty low-cost materials,” says Mason.

It is no surprise that Advanced Ionics is purely targeting industrial hydrogen users — both new and existing — as its customers. Current H2 consumers — mainly oil refiners, ammonia fertiliser producers and chemicals companies — which together use about 70-75 million tonnes of grey H2 produced from unabated natural gas and coal each year, creating as much CO2 as the UK and Indonesia combined.

“Most of heavy industry [that uses hydrogen] — 90%-plus — has waste heat — petrochemicals, ammonia, in the future green steel,” says Mason. “Other applications like methanol, glass manufacturing, just about every single thing that uses hydrogen has waste heat in one form or another. Sometimes it’s low-grade, sometimes it’s high-grade. So we’re really the ideal solution for those processes.”

It also makes economic sense to produce H2 where it is used, to avoid expensive transportation and keep costs low.

Mason explains that a levelised cost of $1/kg of green hydrogen could be achieved with an electricity supply of $20-25/MWh — the lower range of solar power in very sunny countries.

However, those calculations also assume a capacity factor of 90%, meaning that the electrolyser would have to be operating at maximum capacity nine hours out of every ten — which would be almost impossible when powered by variable renewables. So renewable energy credits would need to be bought to ensure the hydrogen is “green”.

“We can also work with intermittent renewables,” Mason adds. “We’ve demonstrated a relatively fast ramp-up in the lab… and we’ve talked to folks about the possibility of high-wind, high-solar applications where you’re at 60%-plus capacity factor.”

‘Secret sauce’

So how is the symbiotic electrolyser different from rival technologies?

Mason describes the equipment he helped design as a “water-vapour electrolyser” — a new class of electrolyser that is “not alkaline, PEM, AEM [anion exchange membrane] or solid-oxide… but hitting that sweet spot that combines some of the best of all these technologies”.

The machine operates in the same way to other electrolysers, using electrodes and an electric current to split water molecules into hydrogen and oxygen.

Advanced Ionics’ electrodes are made from “matched, engineered porous metal”, with an electrolyte made from “composite ionic materials”.

These have “significant tunability, meaning our technology does not require delicate perfluorinated membranes or expensive, brittle ceramics”, Mason says.

“We have a pretty good team that has experience in battery materials, fuel cells, lithium-ion, lead-acid batteries, electrolysers, solar cells, textiles. So we brought together all of these threads of knowledge and asked ourselves, ‘if the goal is to make an electrolyser that runs at these temperatures, what materials and what engineering do we need to enable that?’” he adds. “So we started from the ground up to really architect the platform coming from that angle.”

Mason declines to give any more information about the electrolyser.

“We have a secret sauce that we don’t disclose with anybody,” he says. “There's a bit of secret sauce in every component that we use.”


At this stage, the symbiotic electrolyser is still a lab-based technology starting on the long road to commercialisation, and the machine still needs to be proven in the field, with eventual gigawatt-scale production required to beat competitors on cost, Mason admits.

The good news is that Advanced Ionics has secured $4.2m in financing — led by Boston-based climate tech venture capital firm Clean Energy Ventures — that will enable the deployment of the initial pilot projects.

“We’re currently in negotiation for private pilot deployment partners, the learnings from which will inform design enhancements for commercial units,” Mason explains, adding: “We expect to take commercial orders in 2024 and ship in 2025.”

His preference would be to build a factory in southeast Wisconsin, near the company’s Milwaukee headquarters, which would reach 1GW of production capacity by 2030 at the latest.

“The hydrogen market is accelerating quite fast and people are talking about shortages of electrolysers by 2030, that there isn’t going to be enough capacity,” Mason says.

“So we're being very aggressive on our timelines to match the desperate need for green hydrogen supply to decarbonise all aspects of our economy.”