Demonstration of rSOC operation for local grid-connected hydrogen production and utilisation

Expected Outcome

Given the increasing penetration of Renewable Energy Sources (RES), Long Duration Energy Storage (LDES) is essential to facilitate their integration into the power grid and avoid overbuilding infrastructure. Reversible Solid Oxide Cells (rSOC) offer a valuable solution to this problem, also leveraging the effective coupling between the gas and electricity grids. Reversible fuel cells could be a solution to this problem, but they are still in the early stages of commercial deployment, with ongoing research focused on improving efficiency, durability, and cost-effectiveness. The project should demonstrate the use of rSOC for providing services to both the electric and hydrogen grids or proxy environments (e.g., on-site usages) including heat recovery. When operated in electrolysis mode, the MW-scale system should produce hydrogen to then be compressed and injected into the hydrogen infrastructure or a storage solution. When operated in Fuel Cell (FC) mode, the system will consume hydrogen to produce electricity.

Despite their potential, the widespread adoption of rSOC technology still faces several challenges. One of the primary issues is the need for large-scale demonstration projects to validate their performance, reliability, and economic viability in real-world conditions. Additionally, the integration of rSOC systems into the existing electricity grid requires advanced control strategies and robust system designs to ensure seamless operation and grid stability.

The topic of the project will focus on validating the system's ability to support grid stability, also assessing the impact of hydrogen pressure in the hydrogen pipeline, and the stability of energy price. This will contribute to the development of a more flexible and resilient energy infrastructure, supporting the sector coupling and transition to a decarbonised energy system.

Project results are expected to contribute to the following expected outcomes:

• Demonstrate the integration of rSOC to enhance the coupling between the hydrogen and electricity grid;
• Contribute to the definition of best practice guidelines and support regulation definition for the development and monitoring of reversible systems for sector coupling and grid balancing;
• Contribute to the European energy supply and exploitation of Renewable Energy Sources providing solutions for Long Duration Energy Storage (>8 hours) applications;
• Support the integration of scalable and replicable rSOC-based Long Duration Energy Storage (LDES) solutions into European energy strategies and infrastructure planning, enabling more efficient use of renewable generation and reducing the need for overbuilding grid infrastructure.

Project results are expected to contribute to the following objectives and KPIs of the Clean Hydrogen JU SRIA:

• For Pillar 1, “Renewable Hydrogen Production” and sub-Pillar 1, “Electrolysis”: renewable hydrogen to become competitive by scaling up rSOC systems, increasing the efficiency of renewable hydrogen production and increasing profitability by also using the same system for efficient electricity generation, thereby increasing overall utilisation.
• For Pillar 3.2, “Hydrogen end uses – Clean heat and power” and sub-Pillar 1, “Stationary fuel cells”: enhance the flexibility of systems in operation through reversible fuel cells.

Scope

The scope of this topic builds on the significant advancements made by previous European projects in the field of reversible solid oxide cells systems (rSOC). The REFLEX[1] project has developed an innovative renewable energy storage solution called “Smart Energy Hub", which is based on rSOC technology. The SWITCH[2] project focused on the development of a rSOC able to guarantee highly pure hydrogen production in compliance with main industrial and automotive standards. The European project REACTT[3] focused on developing and demonstrating advanced diagnostic and control tools for rSOC, highlighting the importance of monitoring, diagnostics, prognostics, and control tools for SOE and rSOC stacks and systems with the aim of enhancing the system reliability and extend stack lifetime. Within the SO-FREE[4] project, they developed a solid oxide FC-based system for combined heat and power generation. More recently, the 24_7 ZEN[5] project has contributed to understanding Solid Oxide Cells by developing and demonstrating a cutting-edge reversible solid oxide cell (rSOC) power-balancing plant at a 33/100 kW scale, designed to be compatible with both gas and electricity grids.

Despite advances in addressing key technical challenges and demonstrating the feasibility of rSOC systems across various operational contexts, several challenges remain in integrating rSOC systems with existing gas and electric grids. Building on these results, the scope of this topic is to validate the performance, reliability, and economic viability of MW-scale rSOC systems in real-world conditions, providing valuable insights and data to support the broader adoption of this technology to the grid, and generating data which serve as basis for comparison with battery storage of electricity, for instance.

The reversible solid oxide system (rSOC) should be designed, developed, installed, and operated to demonstrate its capability, availability, and reliability in real-world, MW-scale applications.

The costs (CAPEX) of the whole system including multiple stacks, BoP and gas handling system (purification, compression, and control), as well as the costs for the construction and commissioning phase (e.g connection to the electricity/gas grid, electricity/gas/hydrogen costs) of the reversible solid oxide system may be funded. The OPEX (electricity and gas/hydrogen costs in demonstration/business operation) will not be funded.

Key requirements include:

• A minimum system capacity of at least 1 MW in electrolysis mode to ensure that the solution is scalable and representative of real-world deployment scenarios. The system can contain multiple modules. The modules, as building blocks for the whole system, should provide at least 10 kW electrolysis power. Modules can contain several stacks to reach at least 10 kW electrolysis . This will help in addressing the knowledge gaps associated with rSOC;
• The system should be designed to be able to deliver services to the electricity infrastructure, contributing to sector coupling and overall energy system flexibility;
• The rSOC should be connected to the electricity grid. Where relevant, a hydrogen storage system should be included to enable flexible operation in both electrolysis and fuel cell modes. The setup should allow simulation of ancillary service provision and validate the system’s role in sector coupling and grid balancing of the electric grid;
• Leverage hydrogen and/or biofuels/biogas grid connection to enable electricity generation and ensure continuous system operation when it is not operated in electrolysis mode.
• Operation for over 5,000 h under dynamic conditions, including both operation modes (SOFC/SOEC and switching) and H2 purity at least 99.5%, with performance data addressing key operational characteristics such as: • High ramp-up speed and cycling capability.
• Effective heat management strategies.

• Demonstrate at least 1000 h of electrolysis operation at thermoneutral voltage according to nominal temperature with or without temperature adjustment.
• The entire setup should also include the infrastructure required for injecting hydrogen into the hydrogen grid or a storage facility.
• Hydrogen produced from the rSOC should be compressed using a compressor unit to ≥5 bar output from the complete system. This will ensure hydrogen is adequately pressurised for various applications (e.g., injection into the hydrogen infrastructure or storage tanks);
• Implementation of advanced control strategies, robust system design and optimisation of the Balance of Plant (BoP) to guarantee optimal operation and integration of the system in the electric and hydrogen infrastructure (pipeline or storage). This also includes the development of advanced control for reducing cost of maintenance and operative cost, even considering the HiL/SiL approach;
• The solution should explore the potential of reversible systems as a Long Duration Energy Storage (LDES) option, providing power-to-power conversion (from electricity to hydrogen and vice versa) and enhancing the exploitation of renewable energy sources;
• The project should produce comprehensive development and monitoring guidelines for rSOC-based systems aimed at sector coupling, also including support to regulation and standards definition;
• A comprehensive techno-economic analysis (with a focus on balancing the electricity and, potentially, the hydrogen grid) should be conducted, focusing on capital and operational costs, system lifetime and performance under real operating conditions, potential revenues from market participation (e.g., ancillary services, etc.), and the overall economic viability of integrating rSOC systems into the energy value chain;
• The analysis should also include a comprehensive Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) analysis, to evaluate the environmental impacts and economic costs associated with the entire lifecycle of rSOC.

In doing so, the following KPIs should be addressed:

• Roundtrip electrical efficiency (net) of the whole system ≥50% by 2030, with target of ≥60% by 2035. The efficiency should consider the whole system, involving the BoP (e.g., steamer, compressor, H2 processing unit, inverters, etc.) and rSOC connection to the hydrogen infrastructure;
• Reversibility – The system should demonstrate fast transition capabilities, with switching mode time from one configuration to the other equal to at least 5 min by 2030, targeting ≤2 min by 2035;
• The system should ensure a warm start time of at least 10 min achievable by 2030, targeting 5 min by 2035;
• The system should achieve low electrical energy consumption in electrolysis mode (<37 kWh/kg).
• Low level of stack degradation (<0.3%/1000 h);
• Specific cost of stacks <1000 €/kWFuel Cell.

This holistic approach will help unlock the full potential of rSOC technology, contributing to a resilient, flexible, and decarbonised European energy system.

It is expected that Guarantees of origin (GOs) will be used to prove the renewable character of the hydrogen that is produced/used. In this respect consortium may seek out the issuance/purchase and subsequent cancellation of GOs from the relevant Member State issuing body and if that is not yet available the consortium may proceed with the issuance and cancellation of non-governmental certificates (e.g CertifHy[6]).

For activities developing test protocols and procedures for the performance and durability assessment of (reversible) electrolysers proposals should foresee a collaboration mechanism with JRC[7] (see section 2.2.4.3 "Collaboration with JRC"), in order to support EU-wide harmonisation. Test activities should adopt the already published EU harmonised testing protocols[8] to benchmark performance and quantify progress at programme level.

Proposals are expected to demonstrate the contribution to EU competitiveness and industrial leadership of the activities to be funded including but not limited to the origin of the equipment and components as well infrastructure purchased and built during the project. These aspects will be evaluated and monitored during the project implementation.

Proposals should provide a preliminary draft on hydrogen safety planning and management at the project level.

For additional elements applicable to all topics please refer to section 2.2.3.2.

Activities are expected to start at TRL 5 and achieve TRL 7 by the end of the project - see General Annex B.

At least one partner in the consortium must be a member of either Hydrogen Europe or Hydrogen Europe Research.

The maximum Clean Hydrogen JU contribution that may be requested is EUR 8.00 million – proposals requesting Clean Hydrogen JU contributions above this amount will not be evaluated.

Technology Readiness Level - Technology readiness level expected from completed projects

Activities are expected to start at TRL 5 and achieve TRL 7 by the end of the project - see General Annex B.

[1] https://cordis.europa.eu/project/id/691685

[2] https://cordis.europa.eu/project/id/875148

[3] https://cordis.europa.eu/project/id/101007175

[4] https://cordis.europa.eu/project/id/101006667

[5] https://cordis.europa.eu/project/id/101101418

[6] https://www.certifhy.eu

[7] https://www.clean-hydrogen.europa.eu/knowledge-management/collaboration-jrc-0_en

[8] https://www.clean-hydrogen.europa.eu/knowledge-management/collaboration-jrc-0/clean-hydrogen-ju-jrc-deliverables_en