The European Commission and its roadmap for moving towards a competitive low-carbon economy in 2050 sets greenhouse gas emissions targets for different economic sectors . One of the main challenges of transforming Europe´s economy will be the integration of highly volatile renewable energy sources (RES). Especially hydrogen produced from RES will have a major part in decarbonizing the industry, transport and energy sector – as feedstock, fuel and/or energy storage. However, access to renewable electricity will also be a limiting factor in the future and energy efficient technologies the key. Due to a significant energy input in form of steam preferably from industrial waste heat, Steam Electrolysis (StE) based on Solid Oxide Electrolysis Cells (SOEC) achieves outstanding electrical efficiencies of up to 84 %el,LHV. Thus, StE is a very promising technology to produce hydrogen most energy efficiently. GrInHy2.0 will demonstrate how steam electrolysis in an industrial relevant size can: • Be integrated into the industrial environment at an integrated iron-and-steel works with a StE unit of 720 kWAC and electrical efficiency of up to 84 %el, LHV • Operate at least 13,000 hours with a proved availability of >95 % • Provide a significant amount of hydrogen (18 kg/h) while meeting the high-quality standards for steel annealing processes • Produce at least 100 tons of green hydrogen at a targeted price of 7 €/kg to substitute hydrogen based on fossil fuels • Support the most promising Carbon Direct Avoidance (CDA) approach by substituting the reducing agent carbon by green hydrogen to reduce carbon dioxide emissions in the steel production In context with the production of green hydrogen from a steam electrolyser, the steel industry combines both hydrogen and oxygen demand – today and future – and the availability of cost-efficient waste heat from its high-temperature production processes.

High-temperature electrolysis (HT electrolysis) is one of the most promising technologies to address the European Commission´s Roadmap to a competitive low-carbon economy in 2050. Because a significant share of the energy input is provided in the form of heat, HT electrolysis achieves higher electrical system efficiency compared to low temperature electrolysis technologies. Therefore, the main objectives of the GrInHy project focus on: • Proof of reaching an overall electrical efficiency of at least 80 %LHV (ca. 95 %HHV); • Scaling-up the SOEC unit to a DC power input (stack level) of 120 kWel; • Reaching a lifetime of greater 10,000 h with a degradation rate below 1 %/1,000 h; • Integration and operation for at least 7,000 h meeting the hydrogen quality standards of the steel industry; Additional project objectives are: • Elaboration of an Exploitation Roadmap for cost reducing measures; • Development of dependable system cost data; • Integration of a reversible operation mode (fuel cell mode); The objectives are congruent with the call FCH-02.4-2015 and the Multi Annual Work Plan of the FCH JU. The proof-of-concept will take place in the relevant environment of an integrated iron and steel works. Its existing infrastructure and metallurgical processes, which provide the necessary waste heat, increase the project´s cost-effectiveness and minimize the electrical power demand of auxiliaries. As a result, the electrical efficiency of 80 % will be achieved by operating the HT electrolyser close to the thermal-neutral operation point. The installation will consist of an optimized multi-stack module design with 6 stacks modules in parallel (total capacity: 120 kWel). The last project year is dedicated to the testing of 7,000 h and more. This will be achieved due to a high degree of existing knowledge at system level. Lifetime and degradation targets have already been fulfilled at cell level and will be verified by testing an enhanced stack.