To develop and demonstrate a proof-of-concept of complete diesel-powered fuel-cell based 3 kW (net electric) auxiliary power unit (APU) independently in a laboratory real application and possibly, on-board a truck.
Advantageous with Fuel cell – based Auxiliary Power Units (APU) systems:
Provide high efficiency electric power with very low emissions as an alternative to the engine idling, which beside low efficiency results also in high emissions, high noise and mechanical wear of the engine.
- Further development of the the key components and subsystem technologies that have been advanced in previous collaboration projects and move them closer towards commercially viable solutions.
- Provide knowledge on APU assembly on-board trucks, communication between the unit and the vehicle and safety and conformity to regulations.
Final result and impact
The vision of the FCGEN project was to move the FC-based APU systems a major step towards industrialization. The project was targeting several issues which make this possible, among others: system cost, improved system design for better performance, better efficiency and durability, reduced system size and weight. Efficient, durable and cost effective FC-based APU systems provide clean electricity (less CO2 and HCn, very low NOx emissions) and less noise to the driver cabin during stand still conditions compared to the condition when electricity is generated by engine idling.
As expected for the development projects, also FCGEN faced many challenges, mostly in difference of component behaviour compared to manufacturer characteristics when interacting with each other, or their models due to prototype components provided by suppliers, hidden details and partners not knowing each-others work approach.
However, by strict management, work ethics (means) of bringing the problems out, and strong incentive to finish the project successfully, all problems were solved in the best possible way, albeit some with compromises (6 months project time extension and somewhat compromised weight, size and reduced efficiency).
Finally the efficient autonomous operation of the APU was demonstrated using commercially available diesel fuel. The operation reached efficiencies above 25% and was able to power its start-up, and shutdown and recharge the battery on its own. During numerous FP and complete APU testing sessions, the necessary measures to significantly improve the following parameters were identified for future work: bring the efficiency above 35%, shorten start-up time, durability and serviceability.
The FCGEN APU system provides around 80% fuel saving when it is used as electrify source to the truck cabinet under stop phases compared to electricity provided via Internal Combustion Engine (ICE) idling. The reduced consumption results also in same level reduction of CO2 emissions. Compared to diesel-driven APUs a 40% consumption reduction can be expected. The reported idling time of trucks in US in is in the range of 1500 to 2500 h per year, results in fuel costs of 4000-7500€ per year. Even higher value confirmed also by internal project study addressing EU situation makes opportunity for a good business case.
Within the FCGEN project, cheaper fabrication techniques have been developed, such as embossing, to reduce the production costs of a future micro channel coated heat exchanger reactors compared to the currently employed fabrication methods. Further cost reduction is expected via the reduction of precious metal loadings in the fuel processor catalysts and the selection of some cost effective BoP components. In project undertaken cost analysis has shown that in high volume production the cost is estimated to 5235 €, which is only 16% higher than the target for 2023. Moreover, the cost estimation in the FCGEN is based on the current design. It includes many components that can be avoided, replaced and combined. Several of the sensors in the system is only for analysing the system and not needed in a series product. Some of the component has been added to secure the controllability of the system, when the behaviour of the system is better known these components can probably be removed.
Due to the catalytic technologies used in the FCGEN for system heating at start-up, fuel reforming, reformate purification and anode off-gas combustion, the level of emissions NOx, non-methane hydrocarbon, CO and SOx are < 1ppm which are significantly lower than the corresponding emissions produced during ICE idling.
As the FCGEN is one of the first projects which focus on integration of FC-based APU systems targeted for on-board a vehicle and tested under close to real conditions with logistic fuels, the project provides valuable data and findings to vehicle OEMs with respect to various aspects of APU integration on-board the vehicle: mechanical, electrical, communication, safety. This is a powerful step for the commercialization of FC-based APU systems for on-board power generation and may open the path for additional utilization areas for these systems (e.g. electrifications of auxiliaries, H2 supply for other application, etc.).
Project partners have detected commercial interest from OEMs in various transport fields, namely maritime and road recreational vehicles, and are pursuing ways to jointly further increase the TRL level with gained experience: to reduce cost, significantly increase the efficiency, improve reliability, ensure serviceability and durability.
The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under grant agreement n° 277844.