WP2: The ambitious objectives of the project, a voltage of 0.68 V at 1 A cm-2 at only a slight pressurisation, can only be achieved if the flow fields cause minor losses and ensure an almost ideal supply of the MEA. The task of WP2 is the development of the flow fields for the GRASSHOPPER stack. The first design phase was based on a small test cell with an active area of 25 cm2. The multiphysical numerical investigations of the flow field were prepared. The necessary parameterisation of the MEA, was done in the calculation software. In the third development phase, the completely constructed 300 cm2 bipolar plates of the grasshopper stack, are being investigated. Pure and decoupled flow simulations of the anode, cathode and cooling structures have been done separately and multiphysical numerical analysis of the entire cell been done.
WP3: An MEA optimised for stationary applications was developed, with a low platinum loading compared to state-of-the-art stationary power MEAs such as those developed in the previous FCH-JU funded DEMCOPEM project. The MEA was designed to be manufactured on high-volume, continuous roll-to-roll equipment, using techniques developed in automotive catalyst coated membrane (CCM) manufacture. Testing showed that the newly developed MEA could give high power density in flexible, grid assisting operation, along with significant durability, giving a long operating lifetime compared to other high power CCM-based MEAs. Accelerated stress tests and beginning-of-life testing was carried out. JMFC tested the GRASSHOPPER MEA in a single cell with a drive cycle to assess its durability in flexible operation.
WP4: The target of WP4 is to develop a new stack platform with increased nominal stack power under power plant conditions. These stacks should be series manufacturable at lower cost, while maintaining high lifetime and efficiency. WP4 consists of component development, new cell plates and improved cell plate manufacturing. During the development of the cell plate moulding process several iterations were needed. A 3-cell stack was developed and assembled, using MEAs manufactured by JMFC. The stack performance reached the predefined project targets at 0.689 mV at 1 A/cm2. 9 mV above target. Based on these short stack test results, the final specification for the Grasshopper stack was defined. The 132-cell stack with 300 cm2 has an output power of 27 kW at nominal operating conditions. Nominal operating conditions are defined at 1 bar pressure and a current density of 1 A/cm2. Design improvements on MEA ICD design and sealing were identified to improve the manufacturability. A layout and concept for the equipment required for volume production have been developed.
WP5: System modelling and performance optimization: The first period of the project has been dedicated to preliminary simulations of the fuel cell power plant under various scenarios of configuration and component integration options. A first set of results achieved the objective to support the decisional process for defining the plant layout and the early stages of plant design and engineering. The dynamic model of the whole GRASSHOPPER system was prepared, with its calibration and validation from experimental data. Pilot plant simulations achieved the objective to support the ongoing decisional process for defining the plant layout. MW-scale plant simulations are then carried out to explore possibilities of efficiency improvement in plant scale-up. The model supported the control system implementation providing correlation for predictive control.
WP6: The design of a flexible, modular, low cost 100 kW pilot plant were completed. The pilot plant was ready for its operation with two different options of stacks: GH new design and S2tF design. The final integration of the GH stacks and their testing was not possible during the project period. The Factory Acceptance Test (FAT) were divided into two phases: a first test phase without the stacks using dummy piping, and a second phase with the stacks. The GRASSHOPPER pilot plant was transported to Netherland for further testing and later installation on final location.
WP7: The goal is to develop and integrate an interface, Fuel Cell Power Plant to Grid (FCPP2G) that will enable FCPP, to be integrated into Demand Side Management via Virtual Power Plant. FCPP2G will enable extracting flexible operation of FCPP and offer this flexibility for grid supporting services. The latter can be used by different business entities on electricity market (grid operators, aggregators, and others).
The work contained the algorithms for the FCPP2G which supports the interface for the user on the grid side and communication algorithms for the FCPP control interface. The task was completed with the definition of the test strategy. The dedicated FCPP simulator was developed to test the data exchange, communication protocol FCPP state transitions and power response performance.
WP8: Several activities for disseminating the project philosophy, objectives, challenges, progress, and results of GRASSHOPPER project were developed. The GRASSHOPPER website was installed and regularly updated, The planned second workshop was replaced with an online webinar. Two leaflets were produced. Additional marketing material was produced to increase project visibility, such as a graphics design for the pilot plant, demonstration videos and a roll-up. The final business plan was prepared at the end of the project. Main inputs were received from the Advisory Board (AB). The AB consultations were done in form of teleconferences and two physical meetings.
