Flexi-fuel stationary SOFC

Topic description

Specific Challenge:

Solid Oxide Fuel Cell (SOFC) technology is mainly considered for stationary applications. The number of units installed is growing continuously around the world, for a wide range of power (kW to MW). One of its main advantages is that it can be easily fed by different fuels, not only pure hydrogen as it is the case with other fuel cell technologies. Currently, the reference fuel is natural gas abundantly available throughout EU at low cost. Fuel cells operated with natural gas from the grid reduce already significantly the amount of CO2 generated compared to other conventional heat and power generation systems thanks to their higher efficiency, however not entirely.

In order to reach the target of greenhouse gases emissions reduction set by the EU, a reduction of the carbon footprint of the fuel has to be considered, for example by using renewable gases like biogas or hydrogen. In addition, in order to promote the storage of intermittent renewable energies through the power-to-gas concept, blending hydrogen with natural gas into the existing natural gas network is expected, though several questions remain open like the maximum admissible percentage of H2 in the natural gas and the seasonal variability of the content. The challenge is to have SOFCs able to operate under variable fuel mixtures whilst maintaining acceptable levels of performance.

The project should develop and demonstrate in a relevant environment a stationary solid oxide fuel cell system capable to operate under variable fuel mixtures with high electrical efficiency, high heat quality, long lifetime and able to reach the cost level of conventional fuel cell systems.

The project should evaluate the operation of stationary SOFCs designed for conventional natural gas over a wide range of gas compositions including H2 mixture in natural gas from zero to 100% and additions of biogas in the gas grid.

In order to take advantage of the long and costly development done so far on natural gas fed SOFC and of the high number of units already installed, it is expected that the project focuses on the adaptation of existing SOFC systems design made for natural gas to varying mixtures, with the aim of developing the next generation of “flexifuel” fuel cell systems.

The project consortium should include at least 2 SOFC system manufacturers based in EU or H2020 Associated Country.

The project should:

• Evaluate experimentally at lab scale on stack and system level, how the change of fuel can modify the performance and the durability of the fuel cell, taking in particular into account the thermal management, which will be more complex and might affect SOFC lifetime;
• Implement required BoP components allowing the operation window from zero to 100% H2 in natural gas and with additions of purified biogas (CH4 and CO2, no pollutants);
• Define and validate an operation strategy adapted for a flexifuel operation;
• Demonstrate in relevant environment conditions and at system level, for at least 9 months, the operation in such flexifuel operating conditions; it should involve change of fuel (from 100% natural gas or biogas (potentially varying composition of biogas) to 100% H2, going through different levels of H2 admixtures in natural gas/biogas;
• Address safety and certification aspects in a suitable manner taking into account all relevant directives and regulations. These activities should take into account other FCH 2 JU projects working in this area. The project should bring the fuel cell system developed as close as possible to certification considering the applicable legal basis.

TRL at start of project: 4 and TRL at the end of the project: 6.

Any safety-related event that may occur during execution of the project shall be reported to the European Commission's Joint Research Centre (JRC) dedicated mailbox JRC-PTT-H2SAFETY@ec.europa.eu , which manages the European hydrogen safety reference database, HIAD and the Hydrogen Event and Lessons LEarNed database, HELLEN.

Activities developing test protocols and procedures for the performance and durability assessment of fuel cell components should foresee a collaboration mechanism with JRC (see section 3.2.B "Collaboration with JRC"), in order to support EU-wide harmonisation. Test activities should adopt the already published FCH 2 JU harmonized testing protocols to benchmark performance and quantify progress at programme level.

The FCH 2 JU considers that proposals requesting a contribution from the EU of EUR 2.5 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.

Expected duration: 4 years

Flexifuel operation of SOFC systems should target to cover long-term EU policy perspectives. Consequently, the project is expected to have the following impacts:

• Demonstration of long-term operation (> 6000 h) at stack level with degradation rate below 1%/1000h in the operation window from 0 to 100% H2 in natural gas, thus proving the tolerance of H2 content in natural gas up to 100%;
• Demonstrate that BoP components are compatible for this wide range of gas composition, by qualifying them for the 0-100% H2 in natural gas range in laboratory and by integrating them in SOFC systems;
• BoP components allowing to reach the CAPEX targeted by the 2024 MAWP values [56];
• Demonstrate the operation at system level in relevant environment, with an electrical efficiency >48% LHV for the whole 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 (9 months minimum);
• Confirmation that flexifuel operation mode allow to reach the lifetime and efficiencies targeted by the 2024 MAWP values, thus demonstrating that SOFC systems are fully hydrogen ready;
• Decrease of CO2 emissions of SOFC by at least 40% during operation as compared to a standard natural gas fuel cell fed system;
• Demonstrate that the primary energy reduction through cogeneration is available also to pure hydrogen networks.

[56] https://www.fch.europa.eu/page/multi-annual-work-plan

The conditions related to this topic are provided in the chapter 3.3 of the FCH2 JU 2020 Annual Work Plan and in the General Annexes to the Horizon 2020 Work Programme 2018– 2020 which apply mutatis mutandis.