Electrolyzer developers scramble for place in new hydrogen economy

Developers big and small are racing to streamline and improve on established technology to win an early foothold in the nascent hydrogen economy.

The race to find an electrolyzer technology that is scalable, can operate efficiently with intermittent electricity flows from renewable sources, and is affordable is increasingly intense as global clean hydrogen strategies seek a place for the gas at every level of the energy sector.

The number of patent families related to the electrolysis of water rose 18% annually from 2005 to 2020 to 10,894, according to an International Renewable Energy Association (IRENA) and European Patent Office (EPO) patent insight report.

Applications from China totaled 6,383 patent families, followed by Japan, Korea, United States, Germany and France, the study showed.

China currently holds around 61% of the global manufacturing capacity and, by 2027, some 93% of capacity will be shared between China, North America, and Europe, according to a study by the Clean Energy Associates (CEA).

In an increasingly crowded field, each of the electrolyzer developers is looking to differentiate their product, including PEM developers ITM Power and Ohmium, and AEM developer Enapter.

Mainstream Electrolyzer Technologies Comparison

(Click to enlarge) 

Source: Clean Energy Associates - Clean Hydrogen Supply, Technology, and Policy Report H1 2024

Balance of plant included

ITM Power, which has three key clean hydrogen PEM electrolyzers, the Trident, the Neptune, and the Poseidon, includes the balance of plant, or the subsystems and infrastructure around the electrolyzer stack that help keep it running.

At the heart of the company’s electrolyzers is a 2MW 'stack', which is made up of three stacks each the size of an undercounter fridge, says Head of Business Development at ITM Power James Collins.

“The Neptune system, for example, sits in a 40-foot shipping container with a 2 MW unit and all the balance of plant around it to produce hydrogen,” says Collins.

"All you need to do is plug in water and power." 

The ITM Power electrolyzers, or differential pressure electrolyzers, also produce fuel cell grade hydrogen at 30 bar pressure without additional compression or cleaning that many alkaline electrolyzers need to add to their systems to deliver hydrogen to clients at usable levels.

“Those are two big savings, both in terms of money and space,” says Collins.

Keeping down the costs

Indeed, it is the cost of the PEM systems that is their largest challenge using, as they do, precious metals from the platinum group of elements as the catalyst within the electrolyzers.

At Ohmium, which raised some $250 million in funding in April 2023 and expects to be ready to start shipping volumes of around 500 MW a quarter of its Lotus modular PEM electrolyzers by 2025/26, researchers are working hard to keep the iridium content of its catalysts at a minimum.

“We've got two key challenges for the company; one is design, so that you can install in a very modular way and not add costs in the construction process, and the second is to carefully work the supply chain so that we don't have to go find all the Iridium in the world,” says Ohmium CEO Arne Ballantine.

Companies such as Mattiq, that are working on alternative alloys with similar qualities to iridium and platinum, have helped discover more common, less expensive alloys.

“We work on some (alternatives to iridium) ourselves and have been very successful reducing the amount we need,” Ballantine says.

The U.S. startup has delivered to six sites around the world already, and Ballantine notes that, while the U.S. market is important, the company has a global focus and is looking closely at developments in Europe, India, the Middle East, and Australia.

While precious metal supply was his main concern just a few years ago, focus has changed since, he says.

The company strives to be as flexible as possible as the hydrogen economy develops around the world and Ballantine is watching regulatory developments in key countries carefully.

“It's early for the industry. Things are moving very quickly, and people are having a lot of success, which is good,” he says.

PEM alternative

While PEM electrolyzer manufacturers work to keep the cost of their product down, companies such as Enapter have instead focused on the less developed Anion Exchange Membrane (AEM) electrolyzers.

AEM, says Enapter’s Vice President of Strategy (and Business Development) Tim Cholibois, has the potential to be as cheap as alkaline but with the flexibility of PEM when fed with variable electricity sources.

By using a patented dry cathode, Enapter’s electrolyzers have all the technological advantages of PEM systems without the need for costly materials such as iridium and titanium, he says. 

“That's a really important factor that will make it possible for us to achieve the cost reduction that the PEM industry has been promising and likely won't achieve,” says Cholibois.

“The very different composition of the cell makes it much more likely for AEM to become the cheapest electrolyer technology.”

Enapter has started with electrolyzers roughly the size of a microwave with a 2.4 kW stack power.

Due to their modular design, their stacks can be combined in systems with a capacity of up to 15 MW, though Cholibois sees capacity rising to triple-digit megawatts by the end of the decade.

Roughly half of Enapter’s clients use their products for energy storage, with the other half divided into 10% research institutions, 20% industry, and 20% for mobility applications, Cholibois says.

The company has delivered over 6,500 units to over 375 customers in more than 50 countries, he says, though adds that, as the market moves forward, it will also be up to governments to further increase market appetite.

“What the Americans did with IRA completely changed the market,” says Cholibois.

Such policy signals are essential for off-takers to decisively enter into the market and for projects to reach final investment decision (FID), which remains low as legislation is sometimes slow to be defined and implemented.

“FID right now is very low numbers, because legislation is still being finalized and the exact time horizons and criteria being defined,” he says.

By Paul Day