According to Keith Bethune, an Assistant Specialist at HNEI’s Hawai‘i Sustainable Energy Research Facility (HiSERF) fuel cell laboratory, an on-site electrolyzer reached 12.3 years of production, exceeding the expected lifetime of the three original stacks by over 60%. The Proton On-Site H-Series Electrolyzer installed in October 2006, achieved 107,100 hrs of production on the three original electrolyzer stacks. This far exceeded the manufacturer’s expected lifetime of 60,000 hrs for the 2005 stack design. The unit has a maximum production rate of 6Nm3/H (107.6 SLPM) and during operation approximately 3,400 kg of hydrogen were produced supporting fuel cell testing operations at the facility. The overall system, including the Proton electrolyzer, cooling water chiller, and deionized water supply unit had a 99% uptime over the life of the electrolyzer stacks. The majority of the shutdowns were due to peripheral equipment issues, routine maintenance, power outages, and a planned 6 month shutdown of the lab.
The three electrolyzer stacks were replaced in one day and the unit was restarted in mid-August. The ease of stack replacement further contributes to the availability of the equipment and the stack longevity has been attributed to a strict adherence to maintenance scheduling for all components in the system, particularly the quality of the feedwater into the system.
With proper maintenance and maintaining quality inputs into the system (feedwater), electrolyzers are a very reliable source of hydrogen and may even outlast the manufacturer specs.