Efficient electrolysis coupling with variable renewable electricity and/or heat integration

Renewable hydrogen production via electrolysis offers a clean alternative for various industrial and mobility applications. To reach the REPowerEU domestic hydrogen production target of 10 million tonnes of renewable hydrogen by 2030, many large-scale electrolysis production projects will be commissioned between 2025 and 2027 with the massive support of subsidies at EU (e.g. through IPCEI^[1] and Innovation Fund) or national level. Additional large-scale renewable hydrogen projects will be supported by the European Hydrogen Bank. However, considerable effort is needed to achieve these targets due to the many technical, regulatory and economical challenges to be tackled. These challenges include the integration of electrolysis plants into energy systems (concerning electricity, heating and gas networks, both on- and off-power grid, on- and offshore) fed with variable renewable energy (VRE), and the integrated management of heat (both inside the electrolysis plant and in relation to external infrastructures and uses).

When operated flexibly, electrolysers can support grid stability. Increasing levels of renewable electricity penetration to the target defined in the REPowerEU plan brings a range of challenges, some of which could be addressed by hydrogen produced via electrolysis:

• To reduce the need for grid improvements and grid management operations (variable renewable energy curtailment) through dynamic electrolyser operation and cross-sectoral flexibility (connecting power, gas and heat networks), especially in regions with strong current (or planned) variable renewable energy surplus;
• To boost off-grid renewable electricity generation in offshore installations and areas adjacent to underground storage, islands, and remote areas;
• To provide a range of energy storage (including seasonal) and grid services to help match supply and demand, while reducing curtailment, dependencies on fossil fuels and electricity prices;
• To increase the penetration of renewable energy into the energy system (in on- and/or off-grid systems);
• To reduce the need for curtailment of renewable electricity generation at times of excess production.

The EU regulations (Renewable Energy Directive III, Delegated Acts) have laid the foundations of defining renewable hydrogen (Renewable Fuels of Non-Biological Origin – RFNBO) for different hydrogen production contexts (e.g. direct or indirect interconnection of hydrogen production via electrolysis to (additional) sources of variable renewable energy).

Enhanced thermal management can improve overall energy efficiency and offers another optimisation pathway for the economically viable production of renewable hydrogen. This can appear through the valorisation of heat from the electrolysis plant itself, through the integration of heat from renewable sources or heat from industrial processes. Such heat can be valorised in the electrolysis plant itself, or through external stakeholders. In all cases, enhanced and integrated thermal management can contribute to lower the levelised cost of green hydrogen.

Projects should address efficient electrolysis coupling with variable renewable electricity or heat integration or both.

Project results should contribute to all the following expected outcomes:

For all projects:

• Enhanced electrolysis capacity to produce renewable hydrogen (in line with EU regulations);
• Reduction of the levelised cost of hydrogen, including business models for generating additional income;
• Improved overall integration of electrolysis with the energy system.

For projects on coupling with variable renewable electricity:

• Fostering the use of electrolysis plants to balance the electrical network;
• Coupling of multi-MW electrolysis plants to variable renewable energy generation (both on- and off-grid, directly or indirectly coupled);
• Improved and diversified business models for electrolysis plants thanks to the provision of remunerated electrical grid services (at transmission and distribution system level).

For projects addressing heat integration:

• Fostering synergies between electrolysis plants and external heat stakeholders (producers and consumers);
• Improving thermal management within electrolysis plants;
• Improved and diversified business models for electrolysis plants through integrated thermal management and/or integration into heating supply networks.

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

• Improve dynamic operation and efficiency of systems, with high durability and reliability, especially when operating dynamically, with the following KPIs of the Clean Hydrogen JU SRIA by 2030:
  • Hot idle ramp time at electrolyser system level:
    • Alkaline Electrolysis: 10s;
    • Proton Exchange Membrane Electrolysis: 1s;
    • Solid Oxide Electrolysis: 180s;
    • Anion Exchange Membrane Electrolysis: 5s;
  • Stability in constant power sections: 2.5%;
• Demonstrate the value of electrolysers for the power system through their ability to provide flexibility and allow higher integration of renewables;
• Operate efficiently (at system level including balance of plant) and safely (including with reduced gas crossover when relevant) under variable load with adequate flexibility to be coupled with variable renewable energy;
• MW scale direct coupling to renewable generation (both on- and off-grid) including offshore hydrogen production, aiming at identifying the best system configuration to reach competitiveness;
• Consider innovative system designs and improved balance of plant components to reduce parasitic losses and reduce cost (e.g. purpose-built rectifiers, integrated cooling systems, electrical heaters and heat-exchangers), when relevant in optimised electrical integration with renewables;
• Explore the options for utilising by-product oxygen and waste heat.

Several previous and current projects supported by the Clean Hydrogen Partnerhsip such as REMOTE^[2], HYBALANCE^[3], HAEOLUS^[4], ELY4OFF^[5], DEMO4GRID^[6], H2FUTURE^[7], HOPE^[8] and EPHYRA^[9] as well as supported by national funded projects such as such as Energiepark Mainz^[10],have explored different coupling configurations and system optimisations for the integration of hydrogen production with renewable electricity generation and the provision of grid services. Yet further progresses are needed to demonstrate the full potential of this integration. These should increase the capacity of electrolysis plant operators to produce RFNBO respecting the EU Delegated Acts on Renewable Hydrogen requirements on time correlation, while enhancing their business model through the provision of higher levels of remunerated flexibility services to the electrical grid and potentially through heat integration. These progresses should also address improving electrolysis whole system efficiency and robustness towards load variation and power fluctuation. Improvements in the economics of electrolytic hydrogen production may be achieved by valorisation of dissipated heat from electrolysis and/or by integration of renewable or process heat when coupling the electrolyser to a RES or in an industrial plant, as explored in several European projects (such as as GrinHy^[11], GrInHy2.0^[12], MULTIPLHY^[13], SOPHIA^[14], REFLEX^[15], GAMER^[16]).

This topic is open for all technologies of water and steam electrolysis and for synergies with projects funded under topics supported by the Clean Hydrogen JU: HORIZON-JTI-CLEANH2-2024-01-04^[17], HORIZON-JTI-CLEANH2-2025-01-01 and HORIZON-JTI-CLEANH2-2025-01-02.

The following activities are within the scope of this topic:

• Improve storage (hydrogen, demineralised water, heat, power) and plant control strategies to increase overall plant response reactivity while smoothening ramp-up and -down. This may be supported by a connection to a gas network (incl. salt cavern), or other energy storage (gaseous or electrochemical);
• Demonstrate innovative power electronics (e.g. transformer and rectifier, direct DC/DC coupling) and control strategies to maximise flexibility of operation;
• Develop ad-hoc Balance of Plant components for heat integration;
• Optimise heat re-use within the electrolysis plant and/or the integration of the plant with its environment (e.g. heat networks, industry);
• Improve interaction with the electricity grid to perform grid services on command from the grid (e.g., utilising unexpected power production peaks from renewables, thanks to planning and optimisation tools that could benefit of utilising advanced methodologies such as predictive approach and real-time optimisation). Such tools should optimise the renewable coupling and/or heat integration, including on the basis of economic aspects;
• Utilise emerging digital technologies to integrate electrolysers into a highly flexible and resilient energy system, in synergy with calls from Horizon Europe Cluster 5 and Clean Energy Transition partnership;
• Minimise power consumption in stand-by operation and ensure safe operation at high turn-down operation of the electrolyser;
• Provide improved plant designs of >50MW sites with design-inherent increased operating flexibility, providing higher levels of services to the electrical grid (e.g. capacity to absorb black outs from other sites) while better valorising heat, with concrete business cases on at least one plant with a commissioning date before 2030.

Projects should demonstrate developments for at least 6 months on plants in operation at least at the MW scale. Applicants may work on existing electrolyser installations where only the BoP would need to be adapted/modified or on electrolyser installations under development.

It is expected to have an electrolyser manufacturer in the consortium for this topic. In addition, it is encouraged to include a balance of plant manufacturer. Cooperation with renewable hydrogen production plant operators is also encouraged.

The costs for the construction and commissioning phase of the hydrogen production technology/ies maybe funded while costs related to the operation of the hydrogen production plant (e.g., electricity for electrolysers) will not be funded.

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.

It is expected that Guarantees of origin (GOs) will be used to prove the renewable character of the hydrogen that is produced. In this respect consortium may seek out the issuance 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^[18]).

For activities developing test protocols and procedures for the performance and durability assessment of electrolysers and fuel cell components proposals should foresee a collaboration mechanism with JRC^[19] (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^[20] to benchmark performance and quantify progress at programme level.

Proposals should provide a preliminary draft on ‘hydrogen safety planning and management’ at the project level, which will be further updated during project implementation.

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

Activities are expected to 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 6.00 million – proposals requesting Clean Hydrogen JU contributions above this amount will not be evaluated.

The conditions related to this topic are provided in the chapter 2.2.3.2 of the Clean Hydrogen JU 2025 Annual Work Plan and in the General Annexes to the Horizon Europe Work Programme 2023–2025 which apply mutatis mutandis.

[1] Important Projects of Common European Interest

[2] https://cordis.europa.eu/project/id/779541

[3] https://cordis.europa.eu/project/id/671384

[4] https://cordis.europa.eu/project/id/779469

[5] https://cordis.europa.eu/project/id/700359

[6] https://cordis.europa.eu/project/id/736351

[7] https://cordis.europa.eu/project/id/735503

[8] https://cordis.europa.eu/project/id/101111899

[9] https://cordis.europa.eu/project/id/101112220

[10] https://www.energiepark-mainz.de/en/

[11] https://cordis.europa.eu/project/id/700300

[12] https://cordis.europa.eu/project/id/826350

[13] https://cordis.europa.eu/project/id/875123

[14] https://cordis.europa.eu/project/id/621173

[15] https://cordis.europa.eu/project/id/779577

[16] https://cordis.europa.eu/project/id/779486

[17] https://ec.europa.eu/info/funding-tenders/opportunities/portal/screen/opportunities/topic-details/horizon-jti-cleanh2-2024-01-04?keywords=HORIZON-JTI-CLEANH2-2024-01

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

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

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