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Worldwide about 550 hydrogen refueling stations (HRS) were in operation in 2021, of which 38% were in Europe. With their number expected to grow even further, the collection and investigation of real-world station operative data are fundamental to tracking their activity in terms of safety issues, performances, maintenance, reliability, and energy use. This paper analyses the parameters that characterize the refueling of 350 bar fuel cell buses (FCB) in five HRS within the 3Emotion project. The HRS are characterized by different refueling capacities, hydrogen supply schemes, storage volumes and pressures, and operational strategies. The FCB operate over various duty cycles circulating on urban and extra-urban routes. From data logs provided by the operators, a dataset of four years of operation has been created. The results show a similar hydrogen amount per fill distribution but quite different refueling times among the stations. The average daily mass per bus and refueling time are around 14.62 kg and 10.28 min. About 50% of the total amount of hydrogen is dispensed overnight, and the refueling events per bus are typically every 24 h. On average, the buses' time spent in service is 10 h per day. The hydrogen consumption is approximately 7 kg/100 km, a rather effective result reached by the technology. The station utilization is below 30% for all sites, the buses availability hardly exceeds 80%. • Small/medium-sized hydrogen refueling stations performance analysis. • Investigation of fuel cell buses operation under real-world conditions. • Actual demand is lower than the planned maximum capacity suggesting future bus fleets ramp up potentiality. • On average, the fuel cell buses consume 7 kg H2 /100 km, meeting the EU targets. • The majority of the refuelings are performed overnight from 8 p.m. to 3 a.m. to secure capacity and availability. [ABSTRACT FROM AUTHOR]

Many countries in Europe are investing in fuel cell bus technology with the expected mobilization of more than 1200 buses across Europe in the following years. The scaling-up will make indispensable a more effective design and management of hydrogen refueling stations to improve the refueling phase in terms of refueling time and dispensed quantity while containing the investment and operation costs. In the present study, a previously developed dynamic lumped model of a hydrogen refueling process, developed in MATLAB, is used to analyze tank-to-tank fuel cell buses (30–40 kg H2 at 350 bar) refueling operations comparing a single-tank storage with a multi-tank cascade system. The new-built Aalborg (DK) hydrogen refueling station serves as a case study for the cascade design. In general, a cascading refueling approach from multiple storage tanks at different pressure levels provides the opportunity for a more optimized management of the station storage, reducing the pressure differential between the refueling and refueled tanks throughout the whole refueling process, thus reducing compression energy. This study demonstrates the validity of these aspects for heavy-duty applications through the technical evaluation of the refueling time, gas heating, compression energy consumption and hydrogen utilization, filling the literature gap on cascade versus single tank refueling comparison. Furthermore, a simplified calculation of the capital and operating expenditures is conducted, denoting the cost-effectiveness of the cascade configuration under study. Finally, the effect of different pressure switching points between the storage tanks is investigated, showing that a lower medium pressure usage reduces the compression energy consumption and increases the station flexibility. • Single-tank versus multi-tank hydrogen storage system techno-economic analysis for heavy-duty application. • Investigation of the lowest compressor energy consumption for different storage switching points. • The storage system design does not affect the vehicle refueling time and hydrogen dispensed. • The cascade system reduces compressor energy demand and gas heating increases station flexibility and is more economic. [ABSTRACT FROM AUTHOR]