Research projects are not always easy to follow from the outside. Progress happens in work packages, results come in technical deliverables, and the broader significance of what has been achieved can be difficult to see when you are looking at individual data points rather than the full picture.
As OUTFOX moves into its final year, this post steps back and looks at that full picture: what the project set out to do, what it has accomplished, and what the remaining work will produce.
What OUTFOX was set up to solve
The starting point for OUTFOX was a specific problem: solid oxide electrolysis is one of the most efficient technologies available for green hydrogen production, but it operates at a fundamentally different scale from competing technologies.
PEM and alkaline electrolysers are already being deployed at hundreds of megawatts. Solid oxide systems, despite their efficiency advantages, have largely been demonstrated at the kilowatt to single-megawatt scale. The cells are smaller. The stacks are smaller. The manufacturing volumes are lower. And the cost of the technology reflects all of these constraints.
The central objective of OUTFOX was to remove scale as a limiting factor — not by wishing the constraints away, but by doing the engineering and materials science work needed to actually address them. The project was structured around three pillars: scaling up cell and stack dimensions, developing high-volume manufacturing processes, and increasing current density to improve output per unit of cell area.
Nine consortium partners across Europe have been working on these challenges since early 2023. The project is co-funded by the European Union through the Clean Hydrogen Partnership and by UKRI under the UK government’s Horizon Europe funding guarantee.
Cells: from 150 cm² to 900 cm²
The first major area of progress has been in cell development. OUTFOX set out to produce solid oxide electrolysis cells with geometric areas up to 900 cm² — representing a 2-6x increase over the formats that were typical at the project’s start.
TNO and Elcogen have led this work, and the results have been significant. OUTFOX has successfully produced thin cells at the 900 cm² scale, adapting manufacturing processes, support layer recipes, and handling procedures to make larger cells producible within existing production lines rather than requiring entirely new facilities.
The European Commission’s Innovation Radar formally recognised this work as a key advance in the field, identifying the OUTFOX consortium as a leading innovator in high-performance upscaled SOEL cells.
The scale-up of cell area is not simply about making things bigger. Larger cells introduce mechanical stress distributions, microstructure requirements, and manufacturing yield challenges that do not simply scale linearly with size. VTT has contributed to validating stack-level performance with these larger cells, running characterisation and testing work that has generated data on current density and degradation behaviour at the stack scale.
The project’s current density target — at least 0.85 A/cm² in short stack configurations — has been achieved with reference-scale cells. This result is important because current density directly determines hydrogen output per unit of cell area, which in turn drives the economics of the system.
Stacks and systems: toward 80 kW
The second area of progress is in stack architecture and system design. OUTFOX is not just developing better cells — it is developing the stacks and system architectures that can house those cells in configurations capable of operating at industrial scale.
Elcogen (Finland) has been leading stack development and manufacturing, working on new stack generations that incorporate the larger cells and higher current densities developed in the project. A central theme of this work has been design for manufacturing: ensuring that the engineering decisions made at the stack level are compatible with industrial production processes and component supply chains, not just with research-scale assembly.
Convion has been developing the system architecture, drawing on its experience with solid oxide systems across multiple applications. Its 250 kW piloting platform is now at VTT’s Bioruukki test site, where the OUTFOX system demonstration will take place. This platform allows current density to be increased gradually during testing — giving the project the ability to systematically explore operating conditions and identify real-world limits rather than staying conservatively within known boundaries.
The capstone of the system work will be two 80 kW prototype SOEL modules, to be tested at Shell’s facilities in Amsterdam. These tests will run for more than 4,000 hours in total, covering both steady-state operation and intermittent operating conditions that reflect real renewable energy scenarios. The 80 kW scale is large enough to reveal engineering challenges that do not appear at smaller scales, and to generate operational data that makes techno-economic modelling credible at the 100+ MW level.
Techno-economic analysis: the path to €2.7/kg
The third strand of OUTFOX work has been carried out by Politecnico di Milano, which has developed a full-system simulation and techno-economic model for SOEL-based hydrogen production under various scenarios.
The modelling has produced several important findings. It shows that electricity price is the dominant variable in hydrogen production economics — at European average prices, power cost accounts for the majority of the levelised cost of hydrogen. At lower electricity prices, capital cost and capacity factor become more important, pointing toward the importance of co-location with low-cost renewables and high plant utilisation rates.
The modelling also shows that as stack manufacturing scale increases, the cost structure of the plant changes significantly. The stack’s share of total system cost falls, shifting attention to components like high-temperature recuperators and the hydrogen compressor as the next targets for cost reduction. System modularity — specifically, increasing the number of stacks per hot box and centralising compression — can reduce capital cost by up to 40% from the baseline configuration.
On lifecycle emissions, the analysis confirms that the emissions impact of SOEL hydrogen production is dominated by the electricity source. Using renewable electricity largely addresses the operational emissions question. Manufacturing-phase emissions are smaller but non-negligible — with nickel, though present at only 14% of total cell mass, accounting for approximately 40% of manufacturing-phase CO2 due to its extraction and processing footprint.
The modelling supports the €2.7/kg LCOH target as achievable at 100+ MW scale, under conditions of low-cost electricity, high capacity factor, and manufacturing volumes in the gigawatt-per-year range. None of these conditions is guaranteed — but all of them are within reach if the technology, policy, and investment conditions develop as projected.
The webinar series: sharing results publicly
Alongside the technical work, OUTFOX ran its first public webinar series in February and March 2026 — three sessions that brought together project researchers, industrial partners, and external experts to discuss the project’s findings and their broader implications.
The three sessions covered the cell development work (Webinar 1), stack and system design (Webinar 2), and the economic and policy landscape for SOEL deployment (Webinar 3). Together they attracted hundreds of participants from across the hydrogen and clean energy community — researchers, engineers, policy professionals, and industry representatives.
Recordings of Webinars 2 and 3 are now available on the OUTFOX YouTube channel. Webinar 1 will follow shortly.
What the final year will deliver
OUTFOX is scheduled to complete in the first quarter of 2027. The remaining work centres on two areas.
The first is the 80 kW system testing campaign. This will generate the operational data that validates the project’s technical results at the closest scale yet to real industrial deployment — and will feed directly into the design parameters for future multi-MW SOEL systems. How the system behaves over 4,000+ hours of operation, under both steady and intermittent conditions, will be among the most valuable outputs the project produces.
The second is the roadmap. OUTFOX will publish a comprehensive techno-economic and deployment roadmap setting out the pathway from the project’s current results to multi-MW and ultimately gigawatt-scale SOEL deployment. This roadmap will address not only the technical requirements but the manufacturing, policy, and investment conditions that need to be in place. It is intended to be a practical resource for the industry and policy community, not simply a project deliverable.
Public deliverables, research results, and further updates will continue to be shared through the project website and newsletter as the final phase of work progresses.