{"id":3454,"date":"2026-06-18T14:21:14","date_gmt":"2026-06-18T14:21:14","guid":{"rendered":"https:\/\/websites.fraunhofer.de\/iwes-blog\/?p=3454"},"modified":"2026-07-17T11:36:09","modified_gmt":"2026-07-17T11:36:09","slug":"hydrogen-lab-leuna-testing-and-validating-hydrogen-electrolysis-systems-on-an-industrial-scale","status":"publish","type":"post","link":"https:\/\/websites.fraunhofer.de\/iwes-blog\/en\/hydrogen-lab-leuna-testing-and-validating-hydrogen-electrolysis-systems-on-an-industrial-scale\/johannes-hoeflinger","title":{"rendered":"Hydrogen Lab Leuna: Testing and validating hydrogen electrolysis systems on an industrial scale"},"content":{"rendered":"\n

The production of green hydrogen will be a key element of the energy transition. To meet the growing demand in the coming decades, production capacities in Europe must be massively expanded. But how can we ensure in advance that hydrogen systems can be operated safely, efficiently, and reliably? And how can this be done before they are deployed at the final production sites, where they could potentially incur high follow-up costs? How can actual efficiency be independently verified?<\/p>\n\n\n\n

The Hydrogen Lab Leuna (HLL) offers industry, project developers, and operators a scalable testing and validation infrastructure with a pipeline connection, enabling detailed investigations ranging from large-scale system tests in the megawatt range down to individual electrolysis stacks and stack components.<\/p>\n\n\n\n

Outdoor test pads: Megawatt-scale operation under industrial conditions<\/strong><\/h4>\n\n\n\n

The HLL currently offers three flexible outdoor test pads for electrolysers and (hydrogen) systems up to 5 MW, an additional Power-to-X test area, and a 2-MW electrolyzer stack test bench. The test sites are designed for long-term operation and allow systems to be examined 24\/7 over weeks or months under real-world conditions.<\/p>\n\n\n\n

The focus of these test pads is on analyzing the continuous operation of complex systems. At the megawatt scale, conclusions can be drawn regarding the efficiency, long-term stability, and reliability of the system and its components, as well as their interaction. Dynamic operating modes, such as those involving fluctuating power supply, can also be simulated and evaluated here.<\/p>\n\n\n\n

Thanks to its integration into the Leuna industrial chemical site, the facility is connected to the pipeline system of the local chemical network, ensuring a reliable, simple, and high-volume supply of media to the plants. Hydrogen systems and Power-to-X plants are not considered in isolation but are operated within the context of real industrial infrastructure. This allows for the investigation of issues related to the decarbonization of industrial processes under practical conditions.<\/p>\n\n\n\n

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Outdoor test pad with electrolyzer \u00a9Fraunhofer IWES<\/em><\/figcaption><\/figure>\n\n\n\n

Test facility: System tests in the kilowatt range<\/strong><\/h4>\n\n\n\n

The HLL test facility features electrolysis stack test benches ranging from approximately 3 kW to 46 kW. This facility is primarily used to translate laboratory findings into system operation and to conduct targeted investigations of individual stacks under defined yet realistic conditions. Furthermore, these test benches are used for the development and validation of suitable measurement concepts for the accurate, precise, and rapid characterization of the individual components in an electrolysis stack. This includes, for example, the combination in rainbow stacks, the validation and optimization of accelerated stress test protocols, as well as the development of efficient and economical test series.<\/p>\n\n\n\n

Efficiency tests can be conducted on the stack test benches, allowing operating parameters such as temperature, pressure, and electrical load to be specifically adjusted and varied. During longer test campaigns spanning several months, it is also possible to observe and quantitatively evaluate aging and degradation effects.<\/p>\n\n\n\n

These tests provide reliable data on the operational behavior of stacks and form an important basis for evaluating efficiency, stability, and service life. This offers industry partners the opportunity to technically classify systems before transitioning to higher performance classes and to validate design and operational concepts.<\/p>\n\n\n\n

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Exterior view of one of the 46-kW test benches, designed for stacks of 10 cells, at the HLL technical center \u00a9Fraunhofer IWES<\/em><\/figcaption><\/figure>\n\n\n\n
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Interior view of a PEM stack connected to a 46 kW test bench \u00a9Fraunhofer IWES<\/em><\/figcaption><\/figure>\n\n\n\n
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Spray coater for the production of CCMs (catalyst-coated membranes) or CCS (catalyst-coated substrates) for testing in electrolysis cells \u00a9Fraunhofer IWES<\/em><\/figcaption><\/figure>\n\n\n\n

Laboratory: Analytical methods and in-depth understanding<\/strong><\/h4>\n\n\n\n

Determining key material properties \u2013 such as gas permeability and ionic conductivity in ion-conducting membranes \u2013 under electrolysis conditions makes a significant contribution to a better understanding of electrolysis and to predicting material behavior.<\/p>\n\n\n\n

Therefore, in addition to the system-oriented tests conducted in the pilot plant and outdoor facilities at the HLL, analytical laboratory infrastructure<\/a> is available. At this level, scientists conduct electrochemical as well as fluid and gas analytical investigations that enable a detailed understanding of the underlying processes.<\/p>\n\n\n\n

Laboratory analysis serves to classify measurement results from system operation, to specifically investigate individual effects, and to develop and validate measurement and evaluation methods. It thus forms the scientific basis for further testing on the kilowatt and megawatt scales.<\/a><\/p>\n\n\n\n

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Corrosion testing of materials used in electrolysis \u00a9 Fraunhofer IWES<\/em><\/figcaption><\/figure>\n\n\n\n
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Light microscopic examination of a PTL (porous transport layer) \u00a9 Fraunhofer IWES<\/em><\/figcaption><\/figure>\n\n\n\n

Data analysis, modeling, and system integration<\/strong><\/h4>\n\n\n\n

Comprehensive data acquisition and analysis accompany all test levels. The measured data obtained is incorporated into analyses, modeling, simulations, and experimental design, which enable the comparison of operational scenarios, the evaluation of design options, and the identification of optimization potential. To this end, Fraunhofer IWES has developed and established its own cross-system database (H2Labs), which effectively combines and analyzes measurement data, measurement parameters, and metadata. This enables industrially relevant insights to be derived more accurately, more precisely, and more cost-effectively.<\/p>\n\n\n\n

From the research question to the appropriate test setup<\/strong><\/h4>\n\n\n\n

A test project typically begins with a specific technical question, such as regarding efficiency, degradation, dynamics, or other relevant performance metrics. Based on this, we jointly assess whether tests in the laboratory, pilot plant, or megawatt-scale are appropriate and how the project can be implemented at the Leuna site.<\/p>\n\n\n\n

A comprehensive testing portfolio from MW to kW<\/strong><\/h4>\n\n\n\n

The Hydrogen Lab Leuna combines large-scale outdoor test pads, pilot plant infrastructure, and laboratory analytics into a comprehensive testing portfolio. This creates a facility for industry and project developers in which electrolysers and hydrogen systems can be progressively investigated, validated, and further developed \u2013 from megawatt-scale operation under industrial conditions to detailed analysis of individual stacks.<\/p>\n\n\n\n

Research projects at HLL:<\/strong><\/h4>\n\n\n\n