On-site hydrogen refueling stations (HRS) facilitate localized hydrogen production and supply, reducing dependence on

external distribution networks. However, the limited deployment of on-site HRSs has hindered comprehensive analyses of

their operational characteristics and equipment reliability due to a lack of long-term data and maintenance records. This

study examines 3 years (2022–2024) of operational data from an on-site HRS, with a particular focus on 2023, to identify

key failure modes, analyze downtime causes, and evaluate maintenance effi ciency. Among the 74 recorded failures, the most

frequent involved the degradation of the CO removal unit (PSA) in the reformer (23 cases, 31%), piston and gasket wear in

the low-pressure compressor (13 cases, 18%), and refrigerant leakage in the chiller (5 cases, 7%). Reformer failures led to

hydrogen purity issues, requiring an average maintenance time of 19.5 h, while compressor failures caused effi ciency loss and

gas leakage, necessitating 4.3 h of repair. Prolonged maintenance was primarily due to technological immaturity, including

limitations in equipment performance and system reliability. Addressing these issues is essential to enhance the long-term

reliability and operational effi ciency of on-site HRSs, ensuring their viability for widespread adoption.