Skip to main content
European Commission logo print header

Green Industrial Hydrogen via steam electrolysis

Periodic Reporting for period 3 - GrInHy2.0 (Green Industrial Hydrogen via steam electrolysis)

Reporting period: 2022-01-01 to 2022-12-31

Clean Hydrogen from renewable energies is key to a successful cross-sectoral energy transition enabling the EU’s low-carbon economy goal in 2050. However, access to renewable electricity will be a limiting factor in the future and energy efficient technologies will still be important. Due to a significant energy input in form of steam preferably from industrial waste heat, High-Temperature Electrolysis based on Solid Oxide Electrolysis Cells (SOEC) achieves outstanding electrical efficiencies.

Essential element of the GrInHy2.0 project is to produce hydrogen the most energy efficient way while increasing the technological maturity of the High-Temperature Electrolyser (HTE). Although starting with hydrogen production for today’s steel annealing processes, GrInHy2.0 marks an important milestone towards a hydrogen-based, low carbon European steel industry. Here, hydrogen has the potential to reduce today’s process related CO2 emissions by more than 95 %.

The Salzgitter companies Salzgitter Flachstahl GmbH and Salzgitter Mannesmann Forschung GmbH together with the partners Sunfire GmbH, Paul Wurth S.A. Tenova SpA and the French research centre CEA have worked together at the world’s most powerful HTE for the energy efficient production of hydrogen. During the project, the consortium contributed to a detailed analysis of the potentials of renewable hydrogen in the iron-and-steel industry as well as the in-depth understanding of SOEC long-term behaviour on stack level.

With the first implementation of a High-Temperature Electrolyser of the Megawatt-class, GrInHy2.0’s prototype has produced 200 Nm³/h of hydrogen at nominal power input of 720 kWAC. The HTE system consists of up to eight modules with 720 or 1,080 SOECs each, i.e. 24 or 36 stacks, respectively. As in the predecessor project GrInHy, the prototype was fully integrated into Salzgitter’s steelmaking operations and ran on steam from waste heat of the steel production. By the end of 2022 the system was operating for more than 14,000 hours, injecting more than 100 tons of climate neutral hydrogen into the grid. A maximum electrical efficiency of 84.6 %el,LHV was successfully demonstrated with the electrolyser unit onsite in Salzgitter.

In a broader perspective, the project has delivered answers on how to avoid CO2 emissions in the European steel industry by switching to a hydrogen-based primary steelmaking and what it takes.
The first reporting period mostly covered initial and preparational work: Sunfire manufactured the High-Temperature Electrolyser with a target capacity of 720 kWAC producing of 200 Nm³/h and Paul Wurth assembled the Hydrogen Processing Unit consisting of compressor and dryer. In the meantime, SZFG prepared the installation site. For the parallel stack testing, CEA installed and commissioned the test bench for the 20,000- hours testing period.

The second reporting period was mainly dedicated to the commissioning and operation of the GrInHy2.0 system prototype, on one hand, and long-term stack testing, on the other. The first hydrogen was injected during the commissioning stage in December 2020. As of December 2021, the prototype system reached 5,600 hours of operation and produced 42 t of ‘green’ hydrogen. This equalled a time availability of ~ 80 %. System downtimes were mostly due to hardware and software optimisations and installations of replacement HTE modules. Over the year 2021, the production capacity increased to a production rate of 170 Nm³/h with an HTE electrical efficiency of >84 %LHV.

Within the remaining 12 months almost all remaining operational targets were reached. In April 2022 the full capacity of 200 Nm³/h was successfully demonstrated and a record-high electrical efficiency of 84.6 %el,LHV could be communicated over all channels. By the end of 2022 the system was operating for more than 14,000 hours, injecting more than 100 tons of climate neutral hydrogen into the grid.
Dynamic testing showed that once the system is running, load change can be achieved quite quickly. A transient from 30 % load to full production takes less than 15 minutes. Main time-consuming action is the start of further HTE modules from Hot Standby to load operation. Furthermore, a normal shutdown of the system takes 3 minutes only. The long-term testing on the dedicated single-stack test bench experienced unforeseen challenges which is why the milestone of 20,000 h of operation on a single stack could not be achieved. Nevertheless, the dedicated test bench has been operated for a cumulated 17,000 h.

Our analysis of the CO2 avoidance potential of hydrogen for the European steel industry showed that the CO2 emissions of the entire European iron-and-steel industry can be reduced by more than 90 %. However, CAPEX requirements for carbon-neutral steel production are high and operation is only sustainable and economically viable if cheap green energy is available. Two techno-economic studies and one life cycle assessment add to our discussion of the HTE technology.

All project results are published via the European website as well as the project website and were additionally presented to an international audience at a conference in Salzgitter.
Despite its advantages, HTE technology still shows a lower degree of maturity compared to water electrolysis technologies. A specific challenge of the project was to bring HTE closer to the maturity level of PEM and alkaline electrolysers. In this context, GrInHy2.0 has achieved great contributions. The project focused on designing and manufacturing the most powerful SOEC system at that time and on operating it at an integrated iron-and-steel works. Therefore, the project addressed the progress against state-of-the-art from several angles:

This included the technology itself at stack and system level, as well as the integration of green hydrogen from a decentralised electrolyser into the processes of the European steel industry.

Through a multitude of improvements (e.g. efficiency, durability, costs), GrInHy2.0 significantly impacted the competitiveness of green hydrogen production compared to fossil alternatives such as steam methane reforming, as well as the competitiveness of green hydrogen used in Direct Reduction compared to traditional coal-based reduction processes.

Furthermore, GrInHy2.0 changed the perception of using green hydrogen in industrial processes by demonstrating a viable large-scale application for the use of renewable energy. The generated information on the operational, technical and financial performance of the HTE itself and the illustration of the integration into the commercial and technical processes of the customer will ensure that the results have maximum impact for further market deployment.

The aim was to create a viable market by demonstrating how HTE can work in a complex industrial environment improving carbon reductions over existing technologies. Therefore, the project results will be disseminated to decision makers that are likely to commission similar facilities in the near future (potential customers in the same or other relevant industries) and those who provide supportive policies for the technology (e.g. national governments and people of public interest).

GrInHy2.0 provided a significant share of green hydrogen to the iron-and-steel works. In addition, it provided an assessment on the EU market based on the CO2 avoidance potential of hydrogen for the European industry as a whole.
International visitors take a look at GrInHy2.0 in Salzgitter.
GrInHy2.0 Sunfire's high temperature electrolyser in Salzgiter.
Integrational concept of GrInHy2.0 into SZFG’s production site in Salzgitter.