Solid oxide fuel cell combined heat and power: Future-ready Energy

Project Information

SO-FREE

Grant agreement ID: 101006667

DOI

10.3030/101006667

Project closed

EC signature date 15 December 2020

Start date 1 January 2021

End date 30 June 2026

Funded under

• SOCIETAL CHALLENGES - Secure, clean and efficient energy

Total cost

€ 2 835 807,75

EU contribution

€ 2 739 094,00

Coordinated by

AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L'ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBILE
Italy

Periodic Reporting for period 3 - SO-FREE (Solid oxide fuel cell combined heat and power: Future-ready Energy)

Reporting period: 2024-01-01 to 2024-12-31

Summary of the context and overall objectives of the project

Considering the prospected evolution of the gas network in Europe, and the fuel alternatives for residential-commercial-scale SOFC-CHP, likely fuel compositions for the midterm future can be rationally defined. Current gas grid infrastructure regulation relies a lot on safeguarding down-stream appliances (often combustion-based) in terms of the Wobbe Index and other parameters. Large-scale field demonstration projects have shown, however, that up to 20% H2 by volume will not impair most appliances currently connected to the gas grid. Above this limit, all down-stream appliances would have to be changed, therefore one may go directly to 100% H2. 20% H2 by volume is however a very small contribution in terms of energy and will not achieve significant CO2 reduction for equivalent energy transfer. It is important to evaluate which NG-H2 compositions can be viable all things considered, and in the meantime appliances that are fully fuel-flexible will guarantee a smooth transition to any finally to be established range of energy carriers.
The overall objective of SO-FREE is the development of a fully future-ready solid oxide fuel cell based system for combined heat and power generation. This means a versatile system concept for efficient, near-zeroemission, fuel-flexible and truly modular power and heat supply to end users in the residential, commercial, municipal and agricultural sectors.
Beyond the primary objective required by the call topic – i.e. the delivery of a pre-certified SOFC-CHP system allowing an operation window from zero to 100% H2 in natural gas and with additions of purified biogas – the project will endeavour the realization of a standardized stack-system interface, allowing full interchangeability of SOFC stack types within a given SOFC-CHP system. This interface design will be taken to the International Electrotechnical Commission as a New Work Item Proposal for international standardization.
The prototype will be operated to assess compliance with applicable requirements at TRL 6, defining the outstanding pathway to full product certification; then it will run at TRL7 (demonstration in operational environment) providing combined heat and power with natural gas with injections of H2.
Two stacks will be operated (sequentially, by replacing one with the other) within the final prototype, that cover the spectrum of SOFC operating temperatures: 650°C (Elcogen) and 850°C (IKTS).

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the first RP the basis of the design of the final systems is defined. This has comprised:
- an experimental campaign for performance characterisation of the 2 stack modules to be integrated in the system: the campaign is ongoing with a slight delay but seems to be confirming preliminary performance maps provided by stack suppliers
- first definition of a common stack module-system interface
- preliminary design of the first reference system in iterative loop with the activities of stack characterisation and stack module-system interface standardization: the design has been completed at P&ID level
- pre-assessment of the regulatory framework and of applicable directives and standards for certification of the SO-FREE system
Furthermore, the visual identity and communication profile of SO-FREE has been professionally set up, with preparation of dissemination and communication materials. Also the Data management plan has been elaborated and is being compiled with inputs from the Partners as relevant data start to be generated.

In the second RP the pulling out of AVL from the design of their CHP system has led to transfer of commitment to ICI to evaluate and potentially develop AVL's preliminary design into a competing system.
In terms of short stack characterization, a powerful result was obtained in the parallel testing campaign at ENEA and IEN, where the stack operational data were all within 2% of each other and the expected values. The reliability of both ELC's and IKTS's stack manufacturing processes has thus been demonstrated.

In the third RP, the comparison of the 2 system designs (AVL's original one elaborated by ICI and ICI's own) led to a formal approval to proceed with ICI's original design. This uses less components and employs a robust and simple solution for stack temperature control (fuel bypass after the reformer).
Still, optimising the selected design for operation under ALL targeted fuel compositions (NG - pure H2 - 20% blend - 67% blend), with BOTH stack technologies (ELC and IKTS) and achieving ALL efficiency targets (>48% electrical) while staying within budget constraints, proved to be a more difficult and lengthy task than expected.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Impact 1: Plug-and-play residential CHP systems adapted to the full range of SOFC stack technologies, leading to volume increase and cost reductions across the supply chain
Impact 2: Demonstration of long-term operation (>6000 h) at stack level with degradation rate below 1%/1000h in the operation window 0 to 20% and >67% H2 in natural gas, clean biogas and 100% H2, thus proving the tolerance of the SOFC systems to this range of fuels
Impact 3: Confirmation that flexi-fuel operation mode allows the lifetime and efficiencies targeted by the 2024 MAWP values to be reached, thus demonstrating that SOFC systems are fully H2 ready
Impact 4: Demonstrate that BoP components are compatible for this wide range of gas composition, by qualifying them for the 0 to 20% and >67% H2 in natural gas, clean biogas and 100% H2 fuel range and by integrating them in SOFC systems, maintaining CAPEX targeted by the 2024 MAWP values
Impact 5: Demonstrate the operation at system level in relevant environment, with an electrical efficiency >48% LHV for the defined operation window from 0 to 100% H2 in natural gas, a behaviour and a degradation rate similar to natural gas-fed SOFC systems, and with availability >90% over the operating duration
Impact 6: Decrease of CO2 emissions of SOFC by at least 40% during operation as compared to a standard natural gas fuel cell fed system and demonstrate that the primary energy reduction through cogeneration is available also to pure H2 networks
Impact 7: Strengthen the competitiveness of European fuel cell industry
Impact 8: Consolidation of background research results into competitive products
Impact 9: Recommendations for international standardisation of a stack module-system interface through a New Working Item Proposal and update of current standards
Impact 10: Making SOFC-CHP systems ready for increased H2 concentration in NG contributes to increase reliability and to provide flexibility to the energy system, allowing easier penetration of further RES power capacity.
Impact 11: Thanks to the standardised stack module-system interface European SOC industries could upscale manufacturing thus investing more in high-level job creation and market cultivation.

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At-a-glance description of SO-FREEE