Hydrogen is often discussed as an energy carrier, an industrial feedstock or a climate solution. All three are true. But physically, the hydrogen transition is also a materials challenge. Electrolysers, fuel cells, storage systems, compressors, pipes and balance-of-plant equipment all have to be built before hydrogen can play the role assigned to it.
That is where the circular problem begins. The hydrogen economy is being scaled to reduce dependence on fossil fuels, but some of the technologies needed to produce and use green hydrogen depend on scarce and concentrated materials of their own. In PEM electrolysers and fuel cells, that means platinum group metals such as iridium and platinum. In other technologies, it means nickel, membranes, coatings, power electronics and complex assemblies that need long lifetimes and credible recovery routes.
So the circularity question in hydrogen is not whether hydrogen is clean at the point of use. The question is whether the equipment that produces, converts and uses hydrogen can scale without creating a new critical-material bottleneck.
That was already the central lesson from the Blue Paper work on fuel cells and the BlueCity supply-chain tracks on electrolysers. Hydrogen circularity is not a waste topic at the end of the stack's life. It is a design, lifetime, serviceability and material-security question from the start.
Hydrogen is a hardware system, not only an energy system
Start with the physical reality. Green hydrogen is produced by splitting water using electricity. That sounds simple. The equipment is not. Electrolysers are industrial systems made from stacks, membranes, catalysts, bipolar plates, seals, power electronics, pumps, sensors, control systems and water treatment. Fuel cells reverse part of the logic, turning hydrogen back into electricity, with their own stacks, catalysts, membranes and balance-of-plant components.
The stack is where much of the circular pressure sits. It contains the high-value and performance-critical materials. It also determines efficiency, degradation, maintenance cycles and replacement costs.
That makes hydrogen different from a simple commodity story. A hydrogen project is not just a question of producing kilograms. It is a question of how long the equipment lasts, how easily it can be serviced, what materials it locks in, and whether those materials can return to use when stacks are replaced.
A short-lived stack with scarce materials is not a circular solution just because the hydrogen is green. It is a materials liability with a clean-energy label.
The pressure with a target: electrolyser scale-up
The Netherlands has treated hydrogen as a strategic part of industrial decarbonisation, energy storage and port development. The Dutch hydrogen strategy set targets of 500 MW of electrolyser capacity by 2025 and 4 GW by 2030.
Those targets are not just energy targets. They imply a physical build-out of electrolyser hardware, supply chains, installation capacity, grid connections, water systems, maintenance capability and end-of-life routes. Every megawatt of electrolysis capacity pulls materials into the system.
That matters because the technology mix is not materially neutral. Alkaline electrolysers, PEM electrolysers and solid oxide systems have different material profiles, operating strengths and circularity risks. PEM technology is attractive because it can respond quickly and operate flexibly with renewable electricity, but it relies on platinum group metals, especially iridium at the anode and platinum at the cathode. The European Hydrogen Observatory notes that hydrogen technologies such as electrolysers and fuel cells rely on critical raw materials, particularly platinum group metals including platinum and iridium, and that concentration of supply could create bottlenecks for the EU.
That is the strategic tension. The technology that helps integrate variable renewable electricity can also be the technology most exposed to scarce materials.
The pressure without a target: iridium
Iridium is the material that makes the problem visible. It is scarce, produced mostly as a by-product of platinum mining, and difficult to scale independently. TNO has warned that shortages of scarce raw materials such as iridium and platinum could threaten green hydrogen production, noting that EU hydrogen production by 2050 could require more iridium than is currently produced worldwide each year.
More recent research continues to identify iridium as a serious constraint for PEM electrolysis scale-up. A 2025 study estimated annual iridium production at around 7.5 tonnes and found that meeting net-zero deployment scenarios would require major improvements in catalyst efficiency and access to a substantial share of global iridium production.
The exact numbers vary by scenario, technology mix and catalyst-loading assumptions. The direction does not. If hydrogen scale-up depends heavily on technologies that use scarce materials, then circular design is no longer optional. It becomes part of the feasibility case.
That means designing for lower material intensity, longer stack life, serviceability, refurbishment and material recovery. A system that cannot recover its iridium is not only wasting value. It is weakening its own growth path.
The circular levers are also the scale-up levers
Once hydrogen is seen as a hardware and materials system, the circular levers become practical.
Design for durability
Longer stack life reduces replacement demand, lowers lifetime cost and delays the need for new critical materials.
Design for serviceability
Stacks and balance-of-plant components need to be inspected, repaired and replaced without treating the whole system as disposable.
Material efficiency
Reducing iridium and platinum loading is one of the most direct ways to lower critical-material exposure. TNO, for example, is working on techniques such as Atomic Layer Deposition to reduce iridium use in electrolysers.
Stack refurbishment and remanufacturing
A used stack is not automatically waste. If components can be assessed, cleaned, recoated, replaced or remanufactured, part of the value stays in the system.
Critical material recovery
Platinum group metals need credible recovery routes from electrolysers and fuel cells, not only from existing industrial catalyst streams. Research and pilot work is increasingly focused on bringing critical raw materials from electrolysers back into the cycle.
Technology-fit decisions
Not every hydrogen application needs the same electrolyser technology. Matching technology to operating profile, material exposure and lifetime requirements is a circular decision as much as an engineering one.
Asset passports and material documentation
If operators do not know what materials are inside their stacks, where they are, how they have degraded and who has recovery rights, the circular value is already leaking before end-of-life arrives.
These are not sustainability extras. They determine whether hydrogen projects become cheaper, more resilient and more financeable over time, or whether they become dependent on fragile supply chains and expensive replacement cycles.
What the BlueCity electrolyser track showed
The BlueCity electrolyser track made this practical. The point was not to debate hydrogen in the abstract. It was to bring actors from across the supply chain into the same room and ask what has to change for electrolysers to become more circular, serviceable and scalable.
That matters because no single actor controls the full loop. Stack manufacturers control design. Component suppliers control material choices. Project developers control specifications. Operators see degradation in practice. Recyclers know what can be recovered. Investors care about lifetime and residual value. Policy makers shape incentives and targets. If each actor optimises separately, the system produces equipment that works technically but fails circularly.
The track showed that hydrogen circularity lives in the interfaces: between design and maintenance, between procurement and end-of-life, between material scarcity and technology choice, between performance guarantees and refurbishability. The hard part is not naming circular levers. The hard part is turning them into coordinated decisions before the market locks in a linear model.
That was also the lesson from the fuel cell Blue Paper. Fuel cells and electrolysers are often treated as clean-tech endpoints. But the real question is whether the supply chain behind them can support the scale being promised. Lifetime, repairability, stack replacement, catalyst recovery and second-life value are not details. They are the difference between a technology that scales cleanly and one that imports its own resource constraint.
The trap is treating hydrogen as clean by definition
The common failure is to treat green hydrogen as automatically circular because it is produced with renewable electricity. That is too easy.
Green hydrogen can still depend on scarce materials. It can still use equipment that is hard to repair. It can still produce stack waste. It can still create supplier dependencies. It can still be specified in ways that make refurbishment impossible and recovery uneconomic.
The better question is not whether the hydrogen is green. The better question is whether the hydrogen system is circular enough to scale.
That question changes the investment case. It asks which technology fits the use case, how long the stack will last, what the replacement strategy is, how critical materials are recovered, who owns the residual value, and whether the project is creating a future materials liability.
For CFOs and project developers, this is not philosophical. Stack lifetime, maintenance cost and replacement cycles shape the levelised cost of hydrogen. For public programmes, material dependency shapes strategic autonomy. For technology companies, circular design can become a competitive advantage. For industrial users, traceable and durable equipment reduces future procurement risk.
Where Circular Intelligence works
Circular Intelligence works at the point where hydrogen ambition has to become operational and investment logic.
For hydrogen, that means helping technology providers, project developers, industrial users, sector programmes and public bodies identify where circularity actually affects scale-up: stack lifetime, material exposure, technology fit, serviceability, refurbishment, recycling, procurement criteria and residual value.
Our work on fuel cells and electrolysers showed the same pattern repeatedly. The circular economy opportunity is not at the end of the equipment's life. It is in the decisions made before deployment: what is specified, what is documented, what can be serviced, what can be recovered, and which actor has an incentive to keep value in the loop.
The goal is not a better hydrogen story. Hydrogen already has one. The goal is a hydrogen system that can survive contact with material scarcity, operating reality and investment scrutiny. Circularity here is not a branding layer. It is one of the conditions for scale.
What this means for different roles
For technology providers and stack manufacturers
Your design choices set the material intensity, lifetime, serviceability and recoverability of the entire system. Lower iridium and platinum loading, longer-lived stacks and refurbishable architecture are becoming competitive advantages, not sustainability extras. The firms that design for recovery and long life set the cost and resilience benchmark others have to meet; those that lock scarce materials into disposable stacks build their own constraint.
For CFOs and project developers
Stack lifetime, maintenance cost and replacement cycles feed straight into the levelised cost of hydrogen, so circular design is a cost-of-capital and risk question, not green spend. The readiness gap is the variable that decides whether a project is quietly creating a future materials liability or a recoverable asset. Durability, serviceability and recovery routes are what make the investment case hold as material prices move.
For procurement and industrial users
Traceable, durable, serviceable equipment is the most direct way to reduce future procurement and supply risk. The leverage is in the specification: material documentation, recovery rights and refurbishability written in upfront, because by the time a stack needs replacing the circular value is already determined. Buyers who demand this become less exposed when supply tightens.
For engineering and technical teams
Material intensity and recoverability are decided at design, in catalyst loading, stack architecture and how serviceable the system is, often years before anyone tries to recover anything. Your decisions set what is possible later. The most valuable thing you can do is make low loading and recoverability design inputs rather than afterthoughts, and make sure that case is in the room when the engineering trade-offs get made.
For operators and service providers
You see stack degradation and failure patterns in practice, which is the data that determines whether lifetime extension, refurbishment and recovery are feasible at all. That operational knowledge is the input that turns circular intentions into real decisions. The firms that capture and share it shape how the rest of the chain plans replacement and recovery.
For policy makers
Material dependency on iridium and other platinum group metals is a question of strategic autonomy, not only of environment. The missing piece is incentive and allocation design that rewards durable, material-efficient and recoverable systems and helps build the recovery routes, so that scale-up does not import its own bottleneck. Targets for capacity without conditions for circularity risk locking in a linear, import-dependent model.
How to engage
The useful first step is a short readiness conversation. A focused session that identifies which circular pressure is actually binding for your organisation, whether that is stack lifetime, critical-material exposure, technology fit or residual value, where the business and investment case sits today, and which decisions have to be made before deployment rather than at stack replacement. From there the work can run as a focused assessment, a technology-fit or material-strategy design, or ongoing support, scaled to where you are.
References and sourcing note
Key external claims in this piece are attributed in the text to the Dutch hydrogen strategy (the 500 MW by 2025 and 4 GW by 2030 electrolyser capacity targets), the European Hydrogen Observatory (hydrogen technologies' reliance on critical raw materials, particularly platinum group metals), TNO (iridium and platinum scarcity as a threat to green hydrogen, and Atomic Layer Deposition to reduce iridium use), and recent research on iridium constraints in PEM electrolysis (including the 2025 estimate of around 7.5 tonnes of annual iridium production).
Sourcing note: the figures above, in particular the Dutch capacity targets, the iridium production estimate, and the claim that EU 2050 hydrogen could require more iridium than is produced worldwide each year, vary by scenario and assumption and should be reconfirmed against the primary sources (the Dutch government or RVO hydrogen roadmap, the European Hydrogen Observatory, TNO, and the underlying 2025 study) and dated before publication, in line with the verification standard applied to the other explainers in this series.